Method for producing long glass fiber-reinforced propylene resin composition pellets and method for producing injection molded body

A method for producing long glass fiber-reinforced propylene resin composition pellets, the method comprising:

• a step of filling an impregnation die with a melt mixture in which a propylene resin (A), a modified propylene resin (B), an optionally modified polypropylene wax (C), and an organic peroxide (D) have been melt-mixed with a twin screw extruder, then passing a bundle of long glass fibers (E) through the impregnation die, and impregnating the bundle of long glass fibers (E) with the melt mixture to obtain a strand-shaped molded body;
• and
• a step of cutting the strand-shaped molded body to obtain long glass fiber-reinforced propylene resin composition pellets,
• wherein the polypropylene wax (C) satisfies the following (I) to (III):
• (I) a melting point (Tm) is in a range of 120 to 165° C. as measured with a differential scanning calorimeter (DSC);
• (II) a density is in a range of 890 kg/m3 or more and less than 920 kg/m3;
• and
• (III) a number average molecular weight (Mn) is in a range of 2,000 to 10,000 and a molecular weight distribution (Mw/Mn) is in a range of 2.0 to 6.0, as measured by gel permeation chromatography (GPC).