Product-to-Patent Mapping and Patent Validity
Introduction: In the domain of container packaging, the protection of tamper-evident and tamper-proof technologies has become crucial, particularly for food-grade plastic containers. The case of Mold Tek Packaging Limited vs Pronton Plast Pack Pvt. Ltd. examines the nuanced issues of patent infringement, validity, prior art relevance, and the threshold for granting interim relief in intellectual property disputes. This case also sheds light on the standards governing the exercise of equitable jurisdiction in patent disputes.
Factual Background: Mold Tek Packaging Limited is engaged in the manufacture and sale of plastic packaging containers and holds two Indian patents: IN 401417 and IN 298724. Patent IN 401417 relates to a "Tamper-Evident Leak Proof Pail Closure System," which consists of a lid that incorporates lugs along its periphery. These lugs allow the lid to be affixed to a container in a manner that prevents its removal without breaking a tear band, thereby making any tampering evident. Patent IN 298724 relates to "A Tamper-Proof Lid Having Spout for Containers and Process for Its Manufacture." The innovation in IN 298724 includes a spout that allows partial discharge of contents without removing the lid entirely. Both patents are intended for containers used in the storage and transport of food items.
Mold Tek alleged that Pronton Plast Pack Pvt. Ltd. was manufacturing and selling products that were functionally and structurally similar to Mold Tek's patented lids, thus infringing both patents. Photographic comparisons were made, and physical samples were presented in court to demonstrate the similarity between the products.
Procedural Background: Mold Tek instituted CS (Comm) 668/2023 before the learned District Judge (Commercial), Patiala House Courts, seeking an injunction against Pronton Plast for infringing its patents. Along with the suit, Mold Tek filed an application under Order XXXIX Rules 1 and 2 of the Code of Civil Procedure, 1908, seeking ad interim relief. On 20th December 2023, the Commercial Court granted an ex parte ad interim injunction, restraining Pronton Plast from manufacturing, marketing, selling, or dealing with any products that allegedly infringed Mold Tek's patents IN 401417 and IN 298724.
Pronton Plast responded by filing an application under Order XXXIX Rule 4 CPC to vacate the injunction, contending that their product was significantly different and did not infringe the suit patents. They also argued that Mold Tek's patents lacked novelty due to prior art disclosures, and there was suppression of material facts regarding earlier patents, particularly IN 276, which had lapsed.
By order dated 2nd May 2024, the learned Commercial Court vacated the interim injunction, accepting Pronton Plast's arguments about prior art and serious triable issues concerning the validity of the patents. Mold Tek then filed an appeal under Section 13A of the Commercial Courts Act read with Order XLIII of the CPC, challenging the order dated 2nd May 2024 before the Division Bench of the Delhi High Court.
Core Dispute: The central issue in this case is twofold: first, whether Pronton Plast's products infringe Mold Tek's patents IN 401417 and IN 298724; and second, whether the respondent has raised a credible challenge to the validity of Mold Tek’s patents sufficient to warrant vacation of the interim injunction? The dispute also involves procedural questions concerning the standard of review applicable in interim patent litigation, the requirement for product-to-patent mapping versus product-to-product comparison, and the burden of proof in cases where prior art is cited as a defence.
Discussion on Judgments: Several judicial precedents were cited by the parties to support their respective claims.
The respondent relied heavily on F. Hoffmann-La Roche Ltd. v. Cipla Ltd., ILR 2009 Supp (2) Del 551, where the Delhi High Court held that in patent infringement suits, the tenability of the defendant's challenge to patent validity is relevant at the interlocutory stage. If a credible challenge to the validity is raised, interim injunctions may be refused.
The case of Glaverbel S.A. v. Dave Rose & Ors., 2010 SCC OnLine Del 308, was cited to emphasize that where there is a disputed question of fact relating to infringement, interim relief should not be granted, and such questions should be adjudicated at trial.
In Bishwanath Prasad Radhey Shyam v. Hindustan Metal Industries, (1979) 2 SCC 511, the Supreme Court held that to be patentable, an invention must involve an inventive step beyond mere workshop improvement or a simple combination of known elements. This judgment was cited to support the argument that Mold Tek's patents were mere improvements and lacked the required novelty.
The issue of clean hands and suppression of material facts was highlighted through S.P. Chengalvaraya Naidu v. Jagannath, AIR 1994 SC 853, where the Supreme Court held that a person approaching the court must do so with full disclosure of all material facts.
In Aura Synergy India Ltd. v. New Age False Ceiling Co. Pvt. Ltd., (2016) 65 PTC 483, and its subsequent approval by the Division Bench in (2017) 72 PTC 95 (DB), the Delhi High Court emphasized that suppression of material facts can disqualify a plaintiff from seeking interim relief in intellectual property disputes.
The respondent also referred to Gujarat Bottling Co. Ltd. v. Coca Cola Co., (1995) 5 SCC 545, where the Supreme Court held that equitable relief like injunction is discretionary, and the conduct of the party seeking such relief is material.
For assessing infringement, the appellant relied on Sotefin S.A. v. Indraprastha Cancer Society, 2014 SCC OnLine Del 6649, which clarified that patent infringement analysis requires comparing the defendant's product with the claims of the patent, not merely the products in question.
The general principles regarding the credible challenge standard were discussed in Strix Ltd. v. Maharaja Appliances Ltd., 2009 SCC OnLine Del 2825, where the Delhi High Court held that a defendant must produce some acceptable scientific material supported by expert evidence to make out a credible challenge to a patent's validity.
Additionally, the appellant cited Kudos Pharmaceuticals Ltd. v. Natco Pharma Ltd., 2024 SCC OnLine Del 1439, to argue that a credible challenge must be more than a mere possibility of invalidity; it must present a prima facie case that would merit favourable consideration at trial.
Reasoning and Analysis of the Judge: The Division Bench of the Delhi High Court found that the Commercial Court's order dated 2nd May 2024 suffered from significant legal infirmities. The Court held that the Commercial Court failed to properly analyze the issue of infringement. The correct method of analysis requires a product-to-patent mapping, wherein the features of the allegedly infringing product are compared with the claims in the suit patents, not merely with the plaintiff’s product. The Commercial Court’s approach of comparing products without reference to patent claims was held to be erroneous.
The Court further held that in patent litigation, if the defendant raises a defence under Section 107 of the Patents Act, the burden lies on the defendant to establish a credible challenge to the patent's validity. This onus does not shift to the plaintiff merely because the plaintiff describes its invention as an improvement over prior art. The Commercial Court’s reasoning that Mold Tek bore the burden to establish novelty before the trial was fundamentally flawed.
Regarding prior art, the Court noted that the Commercial Court did not conduct a proper analysis of whether the cited prior arts anticipated or rendered the suit patents obvious. Specifically, while Pronton Plast cited IN 276 and IN 288127 as prior arts, the Commercial Court did not perform a claim-by-claim analysis to determine whether the suit patents were actually anticipated or obvious.
The Division Bench also rejected the respondent’s submission that the initial ex parte injunction should be revisited in this appeal, holding that since the respondent had chosen to proceed under Order XXXIX Rule 4 CPC rather than file an appeal against the ex parte injunction, the High Court could not review the 20th December 2023 order in this appeal.
Final Decision: The High Court allowed the appeal and set aside the order dated 2nd May 2024 passed by the learned Commercial Court. The matter was remanded back for de novo consideration of the application under Order XXXIX Rule 4 CPC. The Commercial Court was directed to reconsider the issues of infringement and validity challenge afresh, applying correct legal principles, particularly the product-to-patent comparison method and the proper allocation of burden of proof.
Law Settled in This Case: This case reaffirms that in patent infringement suits, the test for infringement requires a product-to-patent mapping, not product-to-product comparison. The burden of proof in establishing a credible challenge to a patent’s validity under Section 107 of the Patents Act lies entirely on the defendant. The mere existence of prior art is not sufficient to defeat interim relief unless it is demonstrated that the patented invention lacks novelty or is obvious in light of the prior art. Additionally, procedural fairness and equitable considerations must be balanced with substantive patent law principles when courts consider interim injunctions in intellectual property disputes.
Case Title: Mold Tek Packaging Limited vs Pronton Plast Pack Pvt. Ltd.
Date of Order: 11th July 2025
Case Number: FAO (COMM) 114/2024
Neutral Citation: 2025:DHC:5549:DB
Name of Court: High Court of Delhi at New Delhi
Name of Judges: Hon’ble Mr. Justice C. Hari Shankar & Hon’ble Mr. Justice Ajay Digpaul
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
