Legal analysis: whether the patent is useful after 10 years depends on the patent category: 1, and the term of invention patent right is 20 years; 2. The term of the patent right for utility model is ten years; 3. The term of patent right for design is fifteen years, counting from the date of application. Where a patent for invention is granted for four years from the date of application for a patent for invention and three years from the date of request for substantive examination, the patent administration department of the State Council shall, at the request of the patentee, compensate for the unreasonable delay of the invention patent in the process of authorization, except for the unreasonable delay caused by the applicant.
Legal basis: Article 44 of the Patent Law of People's Republic of China (PRC) is under any of the following circumstances, and the patent right shall be terminated before the expiration of the time limit:
(a) failing to pay the annual fee in accordance with the provisions;
(2) The patentee waives his patent right in writing.
Where the patent right is terminated before the expiration of the time limit, it shall be registered and announced by the patent administration department of the State Council.