Companies Must Clear The Way Before Launching Processes That May Infringe Patents: Calcutta High Court

The Calcutta High Court has said companies seeking to enter a market with a process potentially covered by an existing patent must remove legal obstacles before commencing operations, rather than waiting to be sued for infringement.

“In most jurisdictions the Courts now recognize that insofar as patent matters are concerned, if a would be entrant seeks to launch a process which may be covered by an existing patent, it must take steps to clear the way i.e. remove all obstacles before commencing its activities rather than waiting to be sued for infringement. This is purely commercial common sense and the most rational thing to do. If there is an obstacle in your way, clear it out,” Justice Ravi Krishan Kapur observed.

The court made the observation while granting interim relief to rubber chemicals maker NOCIL Ltd in a patent infringement and breach of confidentiality suit against rival Finorchem Ltd and a former NOCIL employee.

Justice Kapur held that NOCIL had made out “a strong prima facie case”, finding that Finorchem had failed to raise a credible challenge to the validity of NOCIL's patents.

NOCIL is one of India's largest manufacturers of rubber chemicals. In or around 2012, it developed a process for manufacturing 4-ADPA (4-aminodiphenylamine), a chemical used as an antioxidant in rubber and polymer applications and as an intermediate in the manufacture of other antioxidants.

The company holds three Indian process patents for manufacturing 4-ADPA, two of which have equivalent US patents.

A former NOCIL employee joined the company in 1987 as a production supervisor and retired on September 30, 2020, as deputy general manager of process technology. He had served as head of operations at NOCIL's Dahej plant and played a key role in developing and implementing the 4-ADPA processes.

He signed a non-disclosure agreement (NDA) with NOCIL on May 11, 2012. The agreement specifically referred to 4-ADPA and covered his involvement in developing the processes.

The dispute arose after Finorchem filed an Environmental Impact and Risk Assessment (EIRA) report for a plant where it proposed to manufacture 4-ADPA. Following enquiries, NOCIL discovered that the former employee had been engaged by Finorchem to manufacture the same product.

After NOCIL issued notices, both respondents filed caveats in different courts. Finorchem applied for its own process patent for 4-ADPA on April 19, 2024. The court directed it on November 26, 2025, to provide proof of the process it used to manufacture the chemical. Finorchem applied to amend its patent application on February 6, 2026.

NOCIL argued that its patents had undergone examination against prior art in different jurisdictions. It contended that Finorchem had failed to discharge its burden under Section 104A of the Patents Act, 1970, and had repeatedly changed its account of the manufacturing process.

Finorchem argued that patent registration did not establish validity and maintained that it had raised a credible challenge.

The court accepted that registration alone did not establish a patent's validity. However, it said a defendant challenging a patent at the interim stage must raise a credible challenge that is “not fanciful, illusory or moonshine but must be prima facie acceptable”.

The court noted that NOCIL's patents had been examined in India and other jurisdictions and commercially exploited for years. Although registration did not create a presumption of validity, “due weightage must be given to the grant”, it said. It also noted that a challenge to NOCIL's equivalent US patents had been dismissed.

The court found that Finorchem had disclosed at least three different versions of its manufacturing process. Its EIRA report described a process substantially identical to NOCIL's, with an apparent difference concerning the catalyst. The court found this explanation to be false because Finorchem proposed to use the same catalyst as NOCIL.

Finorchem later abandoned the process disclosed in its April 2024 patent application. A process disclosed in a subsequent affidavit was also abandoned after the court found it virtually identical to NOCIL's patented process, with “trifling differences creating an illusion of not infringing”.

The court described Finorchem's subsequent patent amendments as “nothing more than an attempt to evade liability for infringement”. It noted that the company had replaced an original molar ratio of 6:1 to 10:1 for aniline and nitrobenzene with the vague expression “predetermined ratio”.

On confidentiality, the court held that the NDA specifically covered the 4-ADPA processes and could not be treated as a general agreement. It rejected the claim that the former employee had worked only in an administrative capacity, noting that he had signed appraisal and assessment reports relating to plant operations and that his qualifications contradicted the claim.

The court also considered his failure to personally affirm any pleading and the evasive account of his recruitment by Finorchem. These circumstances “prima facie indicate that the respondent no. 1 intended to procure breach of the NDA”, it held.

Rejecting the argument that confidentiality and patent infringement claims were mutually destructive, the court said information could remain confidential even if some of its elements were publicly available.

It found that NOCIL had established a strong prima facie case and that the balance of convenience favoured the company. The court also held that NOCIL would suffer irreparable injury without interim protection.

The court granted NOCIL interim protection against Finorchem and disposed of the application seeking urgent relief. It noted that Finorchem had not yet begun commercial production. The question of patent infringement will be decided at trial after expert evidence is examined

The question of infringement will ultimately be decided after an assessment of expert evidence