Propylene resin composition including isotactic polypropylene and polyolefin resin

A propylene resin composition comprising:

• a composition containing polypropylene, 45.about.70 parts by weight, said composition containing polypropylene possessing:
• a portion insoluble in xylene at 25.degree. C. by solvent extraction method of not less than 98.0% by weight;
• an isotactic pentad fraction of not less than 96.5% as determined by .sup.13 C-NMR;
• an isotactic average chain length of not less than 90 as determined by .sup.13 C-NMR;
• and
• a total amount of fractions each of which has an isotactic average chain length of not less than 300 as determined by .sup.13 C-NMR, according to a column fractionation method, of not less than 10% by weight;
• a polyolefin resin selected from the group consisting of polyethylene resin and polypropylene resin, 5.about.20 parts by weight, possessing:
• a ratio of .eta..sub.1 /.eta..sub.2 of 4.about.20, wherein .eta..sub.1 is a complex viscosity at an angular frequency of 10.sup.-1 rad/sec at 190.degree. C., and .eta..sub.2 is a complex viscosity at an angular frequency of 10 rad/sec at 190.degree. C.;
• Tcp of 110.degree..about.130.degree. C., and Tmp/(Tmp-Tcp) of 3.0.about.9.8, wherein Tcp is crystallization peak temperature, and Tmp is melting peak temperature of said polyolefin resin, said Tcp and said Tmp measurements obtained by a differential scanning calorimetry method wherein, for polyethylene, Tcp is measured after raising a temperature of said polyethylene resin to 190.degree. C. and maintaining the temperature for five minutes, then lowering said temperature at a rate of 10.degree. C./minute until said temperature reaches 30.degree. C. and Tmp is then measured by raising said temperature at rate of 10.degree. C./minute to 190.degree. C., and for polypropylene, Tcp is measured after raising a temperature of said polypropylene resin to 230.degree. C. and maintaining the temperature for five minutes, then lowering said temperature at a rate of 20.degree. C./minute until said temperature reaches 30.degree. C., and Tmp is then measured by raising said temperature at rate of 20.degree. C./minute to 230.degree. C.;
• and
• a crystal structure of an a-axis orientation in a diffraction pattern according to an X-ray diffraction method;
• at least one inorganic filler selected from the group consisting of precipitated calcium carbonate, hydrated silicic acid, and hydrated calcium silicate, 5.about.30 parts by weight;
• and at least one inorganic filler selected from the group consisting of talc, mica, and potassium titanate, 5.about.30 parts by weight.