Asia Patent Alliance

Product by process claims

For inventions of objects, usually the structure and special characteristics of the object are used to define the invention. However, especially in the chemical field, it is quite frequent, that inventions of objects are defined by production process. An example for such a claim would be “Product Y produced by production process X”. Such claims are called product-by-process claims. The merit of such claims is, that even if the structure and special characteristics of the object cannot not be made clear until filing, it is still possible to file a patent by defining the invention by the production process.  In Japan, China and Korea such claims are allowed, but in China and Korea the rules are very strict about whether there are other appropriate notations besides the notations about the process. Especially in Korea product-by-process claims are allowed as an additional measure for inventions of chemical substances in case the substance cannot be defined sufficiently by its structure and nature, but definition just by production process, so-called substance by process (product by process) claims are not allowed as a general rule.

As next point, I would like to explain the patentability and validity of rights of product-by-process claims. (see table)

The patentability is judged by the novelty and inventiveness of the defined object. Therefore, if the object is already known to public with a different production method, it does not fulfill the novelty requirement. This is the difference to production process claims. However, if the object is already known to public, but the production process has a special feature and the nature of the object is modified, a patent can be granted in some cases.

On the other hand, when it comes to the interpretation of the validity of the patent right, usually the „Same-Object Theory“ (A theory that says, even if the object was produced by a different production method, the suspected infringing application belongs to the technical scope.) is applied. However, in special cases (applications that put the technical focus on the production process, for example by adding special conditions to the production process in order distinguish the application from prior art.) the “Limit-Theory” (A theory that says, the technical scope is limited to the production process disclosed in the claims. ) is applied.     


Type of Claim

Important point for judgment of patentability

Validity of right

Production Process Claim

Invention of a method

Production Process

Execution of the production process, production and sales of “objects” produced by this method


Product-by-process Claim

Invention of an object

The defined „object“ itself

Production and sales of the defined „object“

(not dependent on the production process) There are exceptions.