This paper addresses what has been described as a primary concern related to patents: even if chemical companies in Montreal Protocol Article 5 Parties can develop their own methods of producing low-GWP refrigerant hydrofluoroolefin (HFO) or using them in the products they make, they could be prevented (absent a license) from selling their products at home and in key markets abroad in countries where restrictive patents have been granted to other companies, at least until the time when challenges to patents are decided or these patents expire.
This paper reviews the status of patents granted on HFO-1234yf in automotive air conditioning (AC) in the US, Europe, and China, covering the largest automotive manufacturing regions in the world. This paper primarily focuses on patents on the use of HFO-1234yf in automobiles, as opposed to patents on the manufacture of HFO-1234yf.