Resin composition, method for producing resin composition, and injection molded article

A method for producing a resin composition comprising a step of melt kneading a mixture without allowing the mixture to pass through a screen mesh, the mixture comprising:

• a component (A):
• a crushed material of waste car bumpers comprising 1 mass % or more and less than 30 mass % of a xylene-insoluble matter;
• a component (B):
• peeled powder of coated film of waste car bumpers comprising 30 mass % or more and less than 50 mass % of a xylene-insoluble matter;
• and a component (C):
• a propylene-based polymer, wherein
• a content of the component (A) is 15 mass % or more and 35 mass % or less, a content of the component (B) is 15 mass % or more and 35 mass % or less, and a content of the component (C) is 30 mass % or more and 70 mass % or less, based on a total mass of the mixture.