Seatback frame structure

A seatback frame structure comprising:

• a reclining mechanism;
• a joining member that is joined to the reclining mechanism;
• a fastening member;
• a seatback frame that forms a frame of a seatback that can support a back of a seated occupant, the seatback frame being fastened to the joining member by the fastening member;
• and
• a restricting member that includes a metal collar and a restricting portion, the metal collar and the restricting portion being fastened, together with the seatback frame, to the joining member by the fastening member, the metal collar and the restricting portion being configured to restrict relative movement of the seatback frame with respect to the joining member when a vehicle is involved in a rear collision,
• wherein
• the metal collar extends through the restricting member and the seatback frame,
• the seatback frame is made of resin,
• the fastening member engages the restricting member on a laterally outer surface of the seatback frame in a width direction, and
• the seatback frame is fixed in a state sandwiched by the restricting member and the joining member.