Iron Man is Marvel's answer to Batman.  Both are gazillionaires who pour their immense fortune (obtained from weaponry) to fund their personal crusades.  Both wield no "super powers".  Both are haunted by loss and are driven by such trauma to save humanity from itself.  But whereas Bruce Wayne's life-mission is to exact vengeance on wrongdoers, Tony Stark aims to have sinful fun while saving the world.  He's not as focused, but he makes up for it with his technological genius.