Patent No. EP3921447 (titled "Process For Refining Steel And Dephosphorization Agent Used In Said Process") was filed by Lhoist Recherche ET Developpement on Feb 4, 2020. The application was issued on Jun 7, 2023.

Patent oppositions filed by competitors challenge the validity of a granted patent. These oppositions are typically based on claims of prior art, lack of novelty, or non-obviousness. They are a key part of the process for determining a patent's strength and enforceability.
| Company | Opposition Date | Representative |
|---|---|---|
| FELS VERTRIEBS UND SERVICE | Mar 7, 2024 | MAIKOWSKI & NINNEMANN PATENTANWALTE PARTNERSCHAFT MBB |
The dossier documents provide a comprehensive record of the patent's prosecution history - including filings, correspondence, and decisions made by patent offices - and are crucial for understanding the patent's legal journey and any challenges it may have faced during examination.
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