Summary
NOCIL Ltd, a leading Indian rubber chemicals maker, sued Finorchem Ltd and a former NOCIL senior employee before the Calcutta High Court for infringing three process patents for 4-ADPA and for misusing confidential information covered by an NDA. The court held that the patents, though not presumed valid, deserved due weight after years of working and examination, and that Finorchem had raised no credible challenge. It found Finorchem’s process substantially the same as the patented one and its conduct lacking in candour, and granted interim relief on 7 October 2026. The ruling matters because it ties together the credible challenge standard, the duty of a would-be entrant to clear the way, and the burden under Section 104A of the Patents Act.
Background
Fourteen years of working a patented manufacturing route, followed by a rival’s environmental report that matched the patentee’s almost word for word: that sequence framed a process patent infringement dispute before the Calcutta High Court, decided on 7 October 2026.
NOCIL Ltd (“NOCIL”), one of India’s largest rubber chemical manufacturers, developed around 2012 a process for making 4-aminodiphenylamine (“4-ADPA”), an anti-oxidant used in rubber and polymer applications. It holds three Indian process patents for 4-ADPA, Nos. 341922, 366559 and 389262, and United States equivalents of two of them. A former NOCIL employee joined in 1987, rose to head operations at the Dahej plant, retired in 2020 as DGM, Process Technology, and had signed a non-disclosure agreement (“NDA”) dated 11 May 2012 that refers specifically to 4-ADPA.
NOCIL grew concerned when it saw an Environmental Impact and Risk Assessment (“EIRA”) report filed by Finorchem Ltd (“Finorchem”) for a plant proposed to make 4-ADPA, and then learnt that Finorchem had engaged the former employee. Both respondents filed caveats after receiving NOCIL’s notices. On 19 April 2024, Finorchem applied for its own process patent for 4-ADPA. On 26 November 2025, the court directed Finorchem to provide proof of the process it uses, and on 6 February 2026 Finorchem applied to amend its patent application. NOCIL sued for patent infringement and breach of confidentiality, and its interim application, heard on 16 September 2026, was decided on 7 October 2026.
Issues
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- Whether Finorchem raised a credible challenge to the validity of the three patents, when grant under the Patents Act, 1970 (“Patents Act”) is not by itself prima facie proof of validity.
- Whether Finorchem’s proposed process infringes the patents on the pith and marrow test, and on whom the burden lies under Section 104A.
- Whether Finorchem’s failure to use pre-grant opposition, post-grant opposition, revocation or a declaration of non-infringement before entering the field weighs against it.
- Whether the former employee breached the NDA and misused trade secrets, and whether Finorchem procured that breach.
- Whether the claims of patent infringement and breach of confidentiality are mutually destructive.
NOCIL’s Arguments
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- The patents are old, established and have been examined against numerous prior arts in India and abroad.
- Finorchem has not discharged the onus under Section 104A of the Patents Act.
- Finorchem took no step to challenge the patents or clear the way, even after notice.
- The respondents’ conduct was evasive, and Finorchem took inconsistent positions on its proposed process.
- Finorchem recruited the former employee surreptitiously and knowingly procured a breach of his NDA; every affidavit came from a Finorchem manager with no personal knowledge, and he filed no statement on oath.
Finorchem’s Arguments
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- Registration does not establish validity, and Section 104A is wholly inapplicable.
- At the interim stage, Finorchem need only show a credible challenge to validity, and it has done so.
The Former Employee’s Arguments
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- He was not privy to confidential information, is not a named inventor, and shared nothing with Finorchem.
- During commissioning, raw materials and component results were coded and kept confidential, so the allegations are vague and conjectural.
Court’s Analysis
A Grant Is Not Proof, But It Is Not Nothing
The court noted that registration is not prima facie proof of validity, because Sections 12 and 13(4) of the Patents Act depart from the trade mark regime, where registration carries that weight. The court further observed that a patent granted after rigorous examination deserves recognition at the prima facie stage. Under Section 107, a defendant may plead every ground of revocation under Section 64, yet the court held that a defendant must still raise a credible challenge, one that is not fanciful or illusory. In this process patent infringement dispute, the court found that old, working patents, exploited without interruption for more than a decade, weighed in NOCIL’s favour.
Clearing the Way Before Entering the Field
The court opined that a would-be entrant planning a process that may be covered by an existing patent must remove the obstacle before starting, rather than wait to be sued. Finorchem had not filed a pre-grant opposition, post-grant opposition, suit for a declaration of non-infringement or revocation application. The court reasoned that this omission weighs at the interim injunction stage in process patent infringement disputes.
Three Versions of One Process
The court found that the EIRA reports of the two companies were virtually identical, and rejected the explanation that one agency prepared both. It held that Finorchem had advanced at least three versions of its process, that the claimed catalyst difference was false, and that the amendments to its patent application, such as replacing a specific molar ratio with a “predetermined ratio” and labelling the second hydrogenation step optional, were attempts to evade liability.
Pith and Marrow, and the Burden Under Section 104A
The court held that infringement is tested by comparing the patent’s claims with the defendant’s process, looking at the pith and marrow, the essential inventive features, and ignoring trifling variations. It found numerous common steps, and held that specific continuous flow reactors were merely varieties of reactors the patents cover generally. The court stated that, once both processes yield the very same product, the defendant must prove its process differs, and distinguished Natural Remedies Pvt. Ltd. v. Indian Herbs Research & Supply Co. Ltd. (2011 SCC OnLine Kar 4561) as a post-trial decision on non-identical products, not authority that validity must be proved first.
Confidence Survives Alongside a Patent
The court observed that the NDA is specific to 4-ADPA and records the former employee’s role in developing unique steps, which his qualifications and signed assessment reports confirmed. It found, prima facie, that Finorchem intended to procure a breach. The court also rejected the argument that confidentiality and infringement claims are mutually destructive, reasoning that a patentee need not disclose everything material to the invention and that information can remain confidential though some elements are public.
Findings
In view of the observations and the arguments presented by both the parties, the Calcutta High Court held that:
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- NOCIL made out a strong prima facie case for interim relief.
- Registration is not prima facie proof of validity, but the grant, long working and exclusive use of NOCIL’s patents weigh in its favour.
- Finorchem failed to raise a credible challenge to validity, and a mere counter-claim does not bar protective relief.
- Finorchem’s process is substantially similar to the patented processes, and its differences are minor and inconsequential.
- Finorchem did not clear the way, suppressed material facts and took irreconcilable positions, which weigh against it in balancing the equities.
- The former employee was bound by an NDA covering the 4-ADPA processes, and Finorchem prima facie intended to procure its breach.
- The infringement and confidentiality claims are not mutually destructive.
- The balance of convenience favours NOCIL, and Finorchem has not begun commercial production; interim relief was granted in terms of prayers (a) and (b) of the Notice of Motion, and the interim application was disposed of.
Case Citation: NOCIL Ltd v. Finorchem Ltd and Anr, IA No. GA-COM/1/2024 in IP-COM/25/2024, High Court at Calcutta, Intellectual Property Rights Division (Original Side), decided on 7 October 2026. Available at https://indiankanoon.org/doc/190873885/.
Authored by Gaurav Mishra, Patent Attorney, BananaIP Counsels
