legal ground
Article 3 of the Measures for the Registration of Patent Pledge: Where a patent right is pledged, the pledgor and the pledgee shall conclude a written pledge contract. The pledge contract can be a separate contract or a guarantee clause in the main contract. Twelfth patent pledge registration application after examination, China National Intellectual Property Administration registration in the patent register, and send the "patent pledge registration notice" to the parties. The pledge was established when it was registered in China National Intellectual Property Administration.