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(11)

EP 4 522 661 A1

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(43) Date of publication: 19.03.2025 Bulletin 2025/12 (21) Application number: 23724004.9 (22) Date of filing: 08.05.2023

(51) International Patent Classification (IPC):  C08B 1/00(2006.01) C08B 1/08(2006.01) C01D 1/40(2006.01) B01D 61/42(2006.01) D01F 2/02(2006.01) D01F 13/02(2006.01) (52) Cooperative Patent Classification (CPC): C08B 1/003; D01F 2/02; B01D 61/422; C08B 1/08; D01F 13/02; C01G 9/00; C01D 5/006; C01D 1/38 (86) International application number: PCT/FI2023/050251 (87) International publication number: WO 2023/218125 (16.11.2023 Gazette 2023/46)

(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: KH MA MD TN (30) Priority: 10.05.2022 FI 20225409 (71) Applicant: UPM-Kymmene Corporation 00100 Helsinki (FI)	(72) Inventors: RISTOLAINEN, Matti 00100 Helsinki (FI) MODIG, Sakari 00100 Helsinki (FI) KOSONEN, Harri 00100 Helsinki (FI) VIRTANEN, Pasi 00100 Helsinki (FI) SAPKOTA, Janak 00100 Helsinki (FI) POHJALAINEN, Teemu 00100 Helsinki (FI) (74) Representative: Papula Oy  P.O. Box 981 00101 Helsinki 00101 Helsinki (FI)