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EP 4 816 856 A1

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(43) Date of publication: 07.10.2026 Bulletin 2026/41 (21) Application number: 24812179.0 (22) Date of filing: 25.11.2024

(51) International Patent Classification (IPC):  G02B 1/10(2015.01) C23C 18/06(2006.01) G02B 27/01(2006.01) C23C 18/02(2006.01) C23C 18/12(2006.01) (52) Cooperative Patent Classification (CPC): G02B 1/10; C23C 18/1216 (86) International application number: PCT/EP2024/083377 (87) International publication number: WO 2025/114177 (05.06.2025 Gazette 2025/23)

(84) Designated Contracting States: AL AT BE BG CH CY CZ DE DK EE ES FI FR GB GR HR HU IE IS IT LI LT LU LV MC ME MK MT NL NO PL PT RO RS SE SI SK SM TR Designated Extension States: BA Designated Validation States: GE KH MA MD TN (30) Priority: 28.11.2023 EP 23212576 (71) Applicant: Merck Patent GmbH 64293 Darmstadt (DE)	(72) Inventors: SIEMIANOWSKI, Simon 64293 Darmstadt (DE) BERKEFELD, Andreas 64293 Darmstadt (DE) HAMBURGER, Manuel 64293 Darmstadt (DE) DOLL, Oliver 64293 Darmstadt (DE) (74) Representative: Merck Patent Association  Merck Patent GmbH 64271 Darmstadt 64271 Darmstadt (DE)