Polypropylene resin, polypropylene resin composition, and foam-injection-molded article

A polypropylene resin composition for foam injection molding, comprising:

• 3 to 50% by weight of a polypropylene resin;
• and
• 50 to 97% by weight of a first linear polypropylene resin having a melt flow rate at 230° C. of not less than 10 g/10 min and not more than 150 g/10 min and a melt tension of less than 2 cN,
• wherein said polypropylene resin is obtained by melt mixing a second linear polypropylene resin, a radical polymerization initiator and a conjugated diene compound, and
• wherein said polypropylene resin has a melt flow rate of more than 30 g/10 min and not more than 250 g/10 min as measured at 230° C. under a load of 2.16 kg;
• a melt tension at 200° C. of not less than 0.3 cN;
• and a loss tangent, tan δ, of not more than 6.0, the loss tangent being a ratio of loss modulus to storage modulus at an angular frequency of 1 rad/s in dynamic viscoelasticity measurement at 200° C.

An foam-injection-molded article, comprising:

• a composition comprising a polypropylene resin or a polypropylene resin composition for foam injection molding, and
• a foaming agent,
• wherein said polypropylene resin composition for foam injection molding comprises
• 3 to 50% by weight of the polypropylene resin;
• and
• 50 to 97% by weight of a first linear polypropylene resin having a melt flow rate at 230° C. of not less than 10 g/10 min and not more than 150 g/10 min and a melt tension of less than 2 cN,
• wherein said polypropylene resin is obtained by melt mixing a second linear polypropylene resin, a radical polymerization initiator and a conjugated diene compound, and
• wherein said polypropylene resin has a melt flow rate of more than 30 g/10 min and not more than 250 g/10 min as measured at 230° C. under a load of 2.16 kg;
• a melt tension at 200° C. of not less than 0.3 cN;
• and a loss tangent, tan δ, of not more than 6.0, the loss tangent being a ratio of loss modulus to storage modulus at an angular frequency of 1 rad/s in dynamic viscoelasticity measurement at 200° C., and
• wherein said foam-injection molded article is produced by foam injection molding said composition.