In the drafting of claims, product claims are typically defined by structural features of products to ensure clarity regarding their scope of protection. However, when structural features alone cannot adequately define a product, the China Patent Examination Guidelines allow the use of physical or chemical parameters for characterization. If neither structural nor parametric features can clearly define the product, method features may be used instead. This is particularly relevant in the chemical field, where the structure of certain chemical products may not yet be fully understood, making it necessary to define them using performance parameters and/or preparation methods.
When parameter features are used in product claims, determining whether they make a substantial contribution to the claim is a complex issue requiring careful examination. A key consideration is whether the parameter features imply a specific structure or composition of the claimed product. This assessment involves analyzing the factors that influence the parameter features and determining whether the technical effect they reflect results from genuine technological advancements.
For instance, in the case of a polymer product, if a claim defines the Young's modulus of the polymer product - a performance parameter of deformation resistance, since Young's modulus varies with the composition of the polymer, indicating that it is a feature associated with the composition of the product and can be regarded as a technical feature that has a defining effect on the product claim. However, when analyzing the technical effect of this parameter feature on the invention in the specification, if the specification only states that the composition affects the parameter feature without demonstrating any unique technical effect, the parameter feature is merely a measurable property of a given composition, and its technical effect is merely brought by the composition. In such cases, if the composition itself does not substantially contribute to the invention, the parameter feature may not be deemed to provide a meaningful contribution either.
Similarly, consider a spherical resin particle claim that defines a light scattering index. This parameter characterizes the particle’s light-scattering performance and is derived from scattering intensity, which correlates with particle size. Here, the parameter can imply structural characteristics and serve as a defining technical feature. Furthermore, if the specification demonstrates that this parameter enhances light-scattering properties beyond prior art, it can be considered to make a substantial contribution to the invention.
In summary, to determine whether performance parameter features significantly contribute to a product claim, it is crucial to assess whether they distinguish the claimed product’s structure or composition from the prior art. If the parameters merely reflect characteristics directly derived from prior art structures or compositions, they may not serve as distinguishing features. Conversely, if they do provide differentiation, the next step is to evaluate whether their associated technical effects and implied structural or compositional features are non-obvious to a person skilled in the art.
