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The patent EP3555412 was granted to Nippon Steel on Jun 28, 2023. The application was filed on Dec 13, 2017 under application number EP17821984A. The patent is currently recorded with a legal status of "Granted And Under Opposition".

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 | Opposition Status |
|---|---|---|---|
| HYDRIL | Mar 28, 2024 | BOULT WADE TENNANT | ADMISSIBLE |
Patent citations refer to prior patents cited during different phases such as opposition or international search.
| Citation Phase | Publication Number |
|---|---|
| DESCRIPTION | FR2952993 |
| EXAMINATION | EP2589846 |
| INTERNATIONAL-SEARCH-REPORT | FR2889727 |
| INTERNATIONAL-SEARCH-REPORT | FR2913746 |
| INTERNATIONAL-SEARCH-REPORT | FR2952993 |
| INTERNATIONAL-SEARCH-REPORT | FR2953272 |
| INTERNATIONAL-SEARCH-REPORT | WO02073076 |
| OPPOSITION | EP3043098 |
| OPPOSITION | EP3159592 |
| OPPOSITION | EP3205918 |
| OPPOSITION | EP3470720 |
| OPPOSITION | US2012286507 |
| OPPOSITION | US4662659 |
| OPPOSITION | US6237967 |
| OPPOSITION | US6347814 |
| OPPOSITION | WO2004040184 |
| OPPOSITION | WO2007017082 |
| OPPOSITION | WO2007149673 |
| OPPOSITION | WO2008110494 |
| OPPOSITION | WO2010047406 |
| OPPOSITION | WO2010069491 |
| OPPOSITION | WO2010076007 |
| OPPOSITION | WO2010118839 |
| OPPOSITION | WO2010133299 |
| OPPOSITION | WO2012025461 |
| OPPOSITION | WO2014187973 |
| OPPOSITION | WO2014202555 |
| OPPOSITION | WO2015007579 |
| OPPOSITION | WO2015086466 |
| OPPOSITION | WO2015194193 |
| OPPOSITION | WO2016056222 |
| OPPOSITION | WO2016097049 |
| OPPOSITION | WO2016108141 |
| OPPOSITION | WO8906330 |
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.
Date
Description
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Dec 11, 2025
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Dec 8, 2025
(Electronic) Receipt
Appeal
Dec 8, 2025
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Notice of appeal
Appeal
Dec 5, 2025
(Electronic) Receipt
Appeal
Dec 5, 2025
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Notice of appeal
Appeal
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Decision to grant a European patent
Search/Exam
May 15, 2023
(Electronic) Receipt
Search/Exam
May 15, 2023
English translation of the claims
Search/Exam
May 15, 2023
Filing of the translations of the claims
Search/Exam
May 15, 2023
German translation of the claims
Search/Exam
May 15, 2023
Letter accompanying subsequently filed items
Search/Exam
Jan 26, 2023
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Intention to grant (signatures)
Search/Exam
Jan 26, 2023
Text intended for grant (clean copy)
Search/Exam
Jan 26, 2023
Sep 8, 2022
(Electronic) Receipt
Search/Exam
Sep 8, 2022
Amended claims with annotations
Search/Exam
Sep 8, 2022
Claims
Search/Exam
Sep 8, 2022
Letter accompanying subsequently filed items
Search/Exam
Sep 8, 2022
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Annex to the communication
Search/Exam
May 10, 2022
Communication from the Examining Division
Search/Exam
May 19, 2021
(Electronic) Receipt
Search/Exam
May 19, 2021
Letter accompanying subsequently filed items
Search/Exam
May 19, 2021
Mar 12, 2021
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(Electronic) Receipt
Search/Exam
Mar 8, 2021
Letter accompanying subsequently filed items
Search/Exam
Mar 8, 2021
Nov 18, 2020
Annex to the communication
Search/Exam
Nov 18, 2020
Communication from the Examining Division
Search/Exam
Nov 12, 2020
Examination started
Search/Exam
Jan 20, 2020
(Electronic) Receipt
Search/Exam
Jan 20, 2020
Letter accompanying subsequently filed items
Search/Exam
Jan 20, 2020
Reply to Written Opinion prepared by the EPO
Search/Exam
Sep 25, 2019
Jul 23, 2019
Jul 19, 2019
Communication to designated inventor
Search/Exam
Jul 19, 2019
Communication to designated inventor
Search/Exam
Jul 19, 2019
Communication to designated inventor
Search/Exam
Jul 19, 2019
Communication to designated inventor
Search/Exam
Jul 16, 2019
Priority search results copy provided by EPO
Search/Exam
Jul 11, 2019
Information regarding early processing
Search/Exam
Jul 3, 2019
Jun 4, 2019
(Electronic) Receipt
Search/Exam
Jun 4, 2019
Request for entry into the European phase
Search/Exam
May 2, 2019
May 2, 2019
Notification of the recording of a change
Search/Exam
Apr 26, 2019
Information on entry into European phase
Search/Exam
Jul 16, 2018
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Copy of the international search report
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Jun 21, 2018
Copy of the international search report
Search/Exam
Jun 21, 2018
Published international application - A1
Search/Exam
Mar 27, 2018
ISR: cited documents
PCTISA
Mar 27, 2018
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Dec 13, 2017
Abstract
PCTISA
Dec 13, 2017
Annex
PCTISA
Dec 13, 2017
Claims
PCTISA
Dec 13, 2017
Description
PCTISA
Dec 13, 2017
Drawings
PCTISA