Whether buying a product that infringes the patent right is also infringement depends on the situation. If the buyer does not know, it is generally not infringement; If the buyer imports products infringing the patent right from the infringer and knowingly sells them, it is an infringement.
Legal objectivity:
Article 75 of the Patent Law shall not be regarded as infringement of the patent right under any of the following circumstances: (1) The patentee or a unit or individual licensed by him uses, promises to sell, sells or imports a patented product or a product directly obtained by a patented method; (2) Having manufactured the same product, used the same method or made necessary preparations for its manufacture and use before the patent application date, and continuing to manufacture and use it only within the original scope; (3) Foreign means of transport temporarily passing through China's territorial waters and airspace use the relevant patents in their devices and equipment for their own needs in accordance with the agreements signed between their countries and China or international treaties to which they are both parties, or on the principle of reciprocity; (four) the use of relevant patents for scientific research and experiments. Article 77 Anyone who, for the purpose of production and operation, uses, promises to sell or sells an infringing patented product that he does not know was manufactured and sold without the permission of the patentee shall not be liable for compensation if he can prove the legal source of the product.