Hi-Tech Chemicals Vs Deputy Controller of Patents

Evidentiary Standards in Post-Grant Oppositions

Introductory Note:This case involves a dispute over a patent for a special coating used in steel production to prevent slag from sticking to pots. The company Hi Tech Chemicals Limited challenged a decision by the patent office that upheld the patent granted to another company, Allied Metallurgical Products Private Limited. The challenge was about whether the patent office properly considered all arguments against the patent, such as whether the invention was truly new and inventive. The High Court in Madras looked into this and decided to send the matter back to the patent office for a fresh look, pointing out that the original decision lacked proper explanations on key points. The court also dealt with a side issue about delaying the appeal filing and a request to undo that delay approval. In the end, the patent stays in place for now, but it depends on the new decision from the patent office.

Factual Background:The story starts with Allied Metallurgical Products Private Limited, a company based in Bangalore, applying for a patent on January 2, 2012. They called their invention "Anti-stick Coating for Slag Pots," which is a material used in steel plants to stop molten waste, called slag, from sticking to the containers that hold it. This makes cleaning easier and saves time and money in factories. They filed a basic description first and a full one later on January 31, 2013. The patent office in Chennai granted them the patent on April 30, 2019, under number 311984.

Not long after, Hi Tech Chemicals Limited, a company from Kolkata, stepped in. They filed what is called a post-grant opposition on the grounds that the patent should not have been given. They said the invention was not new because similar things were already known or sold, it lacked an inventive step meaning it was obvious to experts, and other reasons like not enough details in the description. Hi Tech backed this up with documents like old patents, invoices showing prior sales, and affidavits from people involved.

Meanwhile, Allied had sued someone else in a lower court in Bellary for copying their patented coating. In that suit, the defendant fought back by saying the patent was invalid, so the case moved to the Karnataka High Court where it is still pending.

Procedural Detail:The patent office formed a group called the Opposition Board to look at Hi Tech's challenge. After hearing both sides, the Deputy Controller in Chennai rejected Hi Tech's opposition on July 5, 2023, saying the patent was valid. Hi Tech then appealed this to the Madras High Court under Section 117A of the Patents Act, 1970.

There was a hiccup because Hi Tech filed the appeal late by 51 days. They asked the court to excuse the delay, blaming it on a mix-up with their company name change from private to limited, which happened back in February 2022. The court okayed the delay on December 15, 2023, without hearing Allied first. Later, when Allied got notice of the appeal, they asked the court to cancel that delay approval, saying they weren't given a chance to argue and that Hi Tech had lied about the reason for the delay.

The High Court heard arguments from both sides. Hi Tech's  explained their points with emails showing the name error caused the hold-up. Allied  said it was a fake excuse and pointed to inconsistencies in the emails. The court looked at everything, including affidavits confirming the emails were real, and decided not to cancel the delay approval.

The main appeal and the request to cancel the delay were heard together, with the court reserving judgment on August 19, 2025, and giving the final order on November 18, 2025.

Core Dispute:At the heart of this case was whether the patent office's rejection of Hi Tech's challenge was fair and well-explained. Hi Tech said the Controller ignored important evidence, like a letter from a customer suggesting Allied sold the product before the patent application date, and didn't properly check if the invention was inventive compared to older ideas (called prior arts D6 to D10). They also said additional documents they filed late, like invoices and court papers from the related suit, should have been considered to prove the patent was not new.

Another big point was whether the patent office should have waited for the Karnataka High Court to decide on the patent's validity in the other case. Hi Tech wanted a pause, but the Controller went ahead.

Allied defended the patent office's decision, saying the late documents didn't count under the rules, the prior sale claim wasn't proven, and the other court case didn't involve Hi Tech directly, so no need to wait.

There was also the side fight over the delay in appealing, where Allied accused Hi Tech of misleading the court.

Detailed Reasoning: The court started by handling the request to cancel the delay approval. Allied said they weren't notified before the delay was excused, which was true, so the court let them argue it now even though their request came late. Allied claimed Hi Tech lied about the name change causing the delay, since the change happened in 2022 but the appeal was filed in 2023. They also questioned email authenticity due to different signatures and fonts.

Hi Tech showed emails from September and October 2023 proving the appeal papers were first made with the old name "Private Limited" and corrected to "Limited" later, causing the delay. An affidavit from their lawyer's partner explained the signature differences as normal office variations. Another from the firm's IT person confirmed the emails came from their server.

The court examined these and said while Hi Tech's initial delay excuse lacked details, there was no deliberate lie. The explanation was good enough as "sufficient cause" for the short 51-day delay. So, the request to cancel was rejected.

Moving to the main appeal, the court looked at Hi Tech's plea to pause the patent office case until the Karnataka High Court decided. Hi Tech cited Aloys Wobben and another v. Yogesh Mehra and others, (2014) 15 SCC 360, where the Supreme Court said one person can't challenge the same patent in multiple places at once, like both in the patent office and court. The court discussed this judgment, noting paragraphs 24 and 25 say an opponent must pick one path: either post-grant opposition or revocation in court. 

But here, the Karnataka case was started by someone else, not Hi Tech. The patent office has a duty under the Patents Act, 1970, Sections 25(2) and related rules to decide oppositions. Without a stay order, the Controller had to proceed. The court said extending Aloys Wobben to stop the Controller would go too far. Hi Tech also cited State of H.P and others v. Surinder Singh Banolta, (2006) 12 SCC 484, paragraph 18, for avoiding inconsistent decisions, but the court said it didn't apply directly since the challengers were different.

Next, on whether the patent lacked novelty due to prior sale. Hi Tech pointed to a January 23, 2015 letter from JSW Steel saying Allied supplied "SLAG KOTE" for four years, meaning sales from January 2011, before the February 1, 2012 priority date. The court said this letter alone doesn't prove it was the exact patented product; more proof like orders or specs was needed. But the Controller didn't give any finding on this, which was a mistake. Affidavits from Hi Tech's director and an inventor also weren't mentioned in the decision. This needed rechecking.

On inventive step, Hi Tech cited prior arts D6 to D10, like old patents on similar anti-slag coatings. The Controller dismissed them briefly, saying D6 was for "anti-adherent slag pigment" and different, D7 for a flame-resistant material, and D8-D10 "entirely different." The court said this was too vague; no reasons why they didn't make the invention obvious. This core issue needed better analysis.

About late documents: "Further evidence A" (invoices, notes, permits, tests) and "B" (court papers). The Controller rejected them under Patents Rules, 2003, Rules 55-62, which limit evidence after certain stages. Rule 60 allows more with permission before hearing; Rule 62(4) lets "publications" with five days' notice. Citing Pharmacyclics LLC v. Union of India, order dated 20.11.2019 in W.P.(C) 12105 of 2019, the Controller said they weren't publications.

The court discussed "publication." It's not defined in the Patents Act, but in Copyright Act, 1957, Section 3, it means making available to the public. In context, Rules 57-60 stop new evidence late, so Rule 62(4) is for public-access docs like journals, not private ones like invoices (seller to buyer) or permits (to one person). For court papers, Section 74 of Indian Evidence Act, 1872, makes them public, but not freely accessible without court leave. Citing Briston-Myers Company's Application, (1969 R.P.C.146), Hi Tech said anything given without secrecy is published, but the court said invoices etc. aren't public in that sense; allowing them would bypass evidence rules. Still, since remand, the Controller should rethink under Rule 60.

On Section 3(e) of Patents Act, which bars patents for mere mixtures without synergy (combined effect better than parts), the Controller said the coating works well, but no basis shown. This needed relook.

Decision:The court set aside the July 5, 2023 order and sent the opposition back to a different Controller for fresh decision within four months, after hearing both sides. The patent stays valid till then. 

Concluding Note:This judgment shows how courts ensure patent decisions are thorough and fair, protecting innovation while allowing challenges. It clarifies rules on evidence in patent fights and when proceedings can run together. For businesses, it highlights documenting inventions clearly and challenging patents promptly with strong proof. It balances quick resolution with careful review, helping the patent system work better for everyone.

Case Title:  Hi Tech Chemicals Limited Vs Deputy Controller of Patents and Designs & Anr.

Order Date: 18.11.2025

Case Number: C.M.A.(PT) No.43 of 2023

Neutral Citation: 2025:MHC:2643

Name of Court: High Court of Judicature at Madras

Name of Hon'ble Judge: The Honourable Mr. Justice Senthilkumar Ramamoorthy

Disclaimer: The information shared here is intended to serve the public interest by offering insights and perspectives. However, readers are advised to exercise their own discretion when interpreting and applying this information. The content herein is subjective and may contain errors in perception, interpretation, and presentation.

Written By: Advocate Ajay Amitabh Suman, IP Adjutor [Patent and Trademark Attorney], High Court of Delhi

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Madras High Court Remands Patent Opposition in “Anti-stick Coating for Slag Pots” Case for Fresh Consideration

Chennai, 18 November 2025: In a significant patent litigation development, the Hon’ble Mr. Justice Senthilkumar Ramamoorthy of the High Court of Judicature at Madras delivered judgment on 18.11.2025 (reserved on 19.08.2025) in C.M.A.(PT) No. 43 of 2023 & CMP No. 17701 of 2025, titled M/s. Hi Tech Chemicals Limited v. Deputy Controller of Patents & Designs & Anr.

The appeal was directed against the order dated 05.07.2023 passed by the Deputy Controller of Patents, Chennai, rejecting the post-grant opposition filed by Hi Tech Chemicals Limited against Indian Patent No. 311984 (Application No. 382/CHE/2012) granted to M/s. Allied Metallurgical Products Private Limited for an invention titled “Anti-stick Coating for Slag Pots”.

The Single Judge set aside the Controller’s order and remanded the post-grant opposition for de novo consideration by a different Controller, primarily on the following grounds:

The impugned order failed to record reasoned findings on critical issues raised by the opponent, particularly on alleged prior commercial sale (lack of novelty), inventive step (prior arts D6–D10), and absence of evidence of synergistic effect to overcome Section 3(e) objection.

Inadequate analysis of inventive step in respect of cited prior arts D6–D10.

No findings on affidavits filed by the opponent’s director and the alleged inventor.

The Controller is directed to reconsider admissibility of additional documents filed by the opponent on 30.01.2023 (invoices, consignment notes, court pleadings, etc.) by treating the request as one for leave under Rule 60 of the Patents Rules, 2003.

The Court clarified that “publication” under Rule 62(4) is confined to documents made freely accessible to the public and does not extend to private commercial documents or court records requiring permission/certified copies.

The Court refused to stay the opposition proceedings pending the counter-claim for revocation before the Karnataka High Court, holding that the principle in Aloys Wobben (2014) 15 SCC 360 does not bar the Controller from discharging statutory duties when the revocation petitioner is a different entity.

The patent remains valid and in force pending the outcome of the remanded proceedings, which the Controller (other than the earlier officer) is directed to complete with a speaking order within four months after giving both parties a reasonable opportunity of hearing.

Disclaimer: This is for general information only and should not be construed as legal advice as it may contain human errors in perception and presentation: Advocate Ajay Amitabh Suman, IP Adjutor (Patent & Trademark Attorney), High Court of Delhi.

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