A thermally conductive wrapper’s claimed flame-barrier function cannot be inferred from conductivity alone.

Philip Morris Products S.A. was granted Indian Patent No. 384250 on 14 December 2021 for an invention titled “Heated Aerosol Generating Article with Thermal Spreading Wrap”, relating to a heated aerosol-generating article in which a gathered sheet of aerosol-forming material is radially encircled by a thermally conductive wrapper intended to function as a flame barrier.

ITC Limited filed a post-grant opposition under Section 25(2) of the Patents Act, 1970, alleging, inter alia, lack of novelty, prior use or knowledge, lack of inventive step, insufficiency of disclosure, and that the subject matter was not an invention; it relied initially on documents D1–D6 and subsequently sought to introduce D7–D10.

After the opposition hearing, the Patentee filed two auxiliary claim sets with its written submissions. ITC objected by filing an interlocutory petition (IP-I).

By two orders dated 30 January 2025, the Controller dismissed both interlocutory petitions and rejected ITC’s post-grant opposition.

Whether the writ petition challenging the Controller’s orders dismissing IP-I and IP-II was maintainable despite the statutory appellate remedy under Section 117A of the Patents Act, 1970?

Whether the Controller erred in dismissing IP-I concerning the auxiliary claim amendments and IP-II concerning the Patentee’s fresh written submissions?

Whether the Controller correctly rejected the post-grant opposition on the ground that the claimed invention was novel over prior art D1 and the other cited documents?

Whether the claimed invention lacked inventive step under Section 25(2)(e), either over D1 alone or in combination with D2–D6 and D7–D10?

Whether documents D7–D10, filed after the originally scheduled hearing date under Rule 62(4) of the Patents Rules, 2003, could be considered?

The Court applied Sections 25(2)(b), 25(2)(e), 25(4), 57(3), 117A and Section 2(1)(ja) of the Patents Act, 1970, together with Rules 57–62 of the Patents Rules, 2003.

For novelty, it applied the all-elements rule: a claim is anticipated only where a single prior-art reference discloses every limitation of the claim, expressly or inherently; mosaicing is impermissible for novelty.

For inventive step, the Court relied on Section 2(1)(ja) and the five-step approach stated in F. Hoffmann-La Roche Ltd. v. Cipla Ltd., requiring identification of the skilled person, inventive concept, common general knowledge, differences from the prior art, and whether those differences would have been obvious without hindsight.

The Court also relied on Whirlpool Corporation v. Registrar of Trade Marks and Best Agrolife Ltd. v. Deputy Controller of Patents for the principle that an alternative remedy does not bar writ jurisdiction where there is a credible allegation of breach of natural justice, jurisdictional error, or failure to consider material grounds.

In relation to additional publications, the Court considered Pharmacyclics LLC v. Union of India, while holding that Rule 62(4) did not impose an absolute bar against accepting publications after the first scheduled hearing where special circumstances justified their admission.

The Court held that the writ petition was maintainable because ITC alleged that IP-II had been decided under an erroneous understanding of the relief sought and that material procedural prejudice had resulted.

However, on examination, the Court found that although the Controller had incorrectly treated IP-II as relating to the auxiliary amendments, the Patentee’s fresh submissions largely explained distinctions already embedded in the claims and specification, particularly the difference between metal foil and metal-paper laminate and the meaning of a “gathered sheet”; they did not introduce a materially new case requiring exclusion.

IP-I was also correctly dismissed because the Patentee did not pursue the auxiliary amendments and instead proceeded on the granted claims after being advised to follow the procedure under Section 57(3).

On the merits, the Court found that D1 did not disclose every limitation of Claim 1.

Although D1 disclosed an electrically heated aerosol-generating article, tobacco material, a wrapper, and heat-conductive metallic material, it did not disclose the claimed gathered sheet of aerosol-forming material in the relevant configuration or the specific functional relationship whereby the wrapper acted as a thermally conducting flame barrier against externally applied flame.

The Court distinguished D1’s wrapper, which functioned primarily as a heat sink or medium for transferring heat from the heating element into the tobacco, from the patented wrapper, which functioned as a heat dissipator to spread heat and mitigate flame-induced ignition.

The Court further held that D2–D6 concerned combustible smoking articles and did not provide a relevant teaching or motivation for modifying D1 to solve the problem addressed by the patent.

D7, though admitted for consideration in the appeal, disclosed aluminium foil for uniform heat transfer and control of combustion during electrically controlled heating, not a wrapper configured to spread heat from an externally applied flame and prevent ignition.

The Court held that equating aluminium’s thermal conductivity with the claimed flame-barrier function was an impermissible hindsight inference.

It held that the writ petition was maintainable, but found no substantive prejudice warranting interference with the interlocutory orders.

IP-I was rightly dismissed because the auxiliary amendments were not pursued, while the objection in IP-II lacked merit because the Patentee’s further submissions did not materially depart from the claims, specification, or earlier case.

On the patent merits, the Court upheld the Controller’s findings that Claim 1 and the dependent claims were novel and involved an inventive step over D1–D6 and, even after considering D7, that the cited prior art neither disclosed nor rendered obvious the claimed thermally conductive wrapper functioning as a flame barrier against externally applied flame.

The orders dated 30 January 2025 were therefore not interfered with, and pending applications were disposed of accordingly.