The study looked at how environmental rules and investments in protecting the environment affect the development of green technology in heavily polluting industries. They found that environmental rules can first slow down and then boost green technology innovation in companies, with a turning point at a certain level of regulation. They also discovered that companies invest in environmental protection as a result of these rules, which in turn helps drive green technology innovation. State-owned companies are particularly influenced by environmental rules, leading to more green technology development. These findings are important for governments making environmental policies and for companies aiming for sustainable growth.