The Delhi High Court recently, in the case of Albemarle Corporation vs The Controller of Patents [C.A.(COMM.IPD-PAT) 19/2022; decision dated July 7, 2025], allowed an interlocutory application seeking to introduce an auxiliary set of claims during the appeal against the refusal of patent application number 2897/DELNP/2012, entitled “Solvent Systems Having No Flash Point and Methods Using Such Solvent Systems for Dissolving Rigid Polyurethane Foams”.

The subject application was refused by the Controller of Patents on the grounds of lack of novelty, lack of inventive step and insufficiency of disclosure. In the instant appeal, Albemarle did not contest the impugned refusal order and only sought the permission to amend the claims of the subject application. The auxiliary claim set narrowed the scope of the original claims by disclaiming the solvent system for cleaning polyurethane foam from an article, and confining the claim to only the process for cleaning polyurethane foam from an article.

The Court referred to its earlier decision in Societe Des Produits Nestle SA vs Controller of Patents and Design and Anr. [C.A.(COMM.IPD-PAT) 22/2022] to reaffirm that the Patents Act does not impose any bar on the amendment of a patent application or specification at the appellate stage. It reiterated that such amendments are permissible, provided they comply with the requirements of Section 59 of the Act.

Upon examining the original and auxiliary claims, the Court concluded that the amended claims were not outside the purview of Section 59(1). It noted that the amendments merely narrowed the scope of the original claims without introducing new matter, thus satisfying the statutory conditions.

In light of these findings, the Court allowed the auxiliary claim set to be taken on record and directed that the subject patent application be revived. The matter was remanded to the Patent Office for fresh consideration, limited to the amended claims.