How long does it take to declare a chemical patent?

More than three years. Within three years from the date of filing, the patent administration department of the State Council may, at the request of the applicant, conduct substantive examination of the application at any time; If the applicant fails to request substantive examination within the time limit without justifiable reasons, the application shall be deemed to have been withdrawn, and the authorization notice may be received after more than 3 years.