(19)

(11)

EP 4 165 243 A1

(12)

(43) Date of publication: 19.04.2023 Bulletin 2023/16 (21) Application number: 21734378.9 (22) Date of filing: 14.06.2021

(51) International Patent Classification (IPC):  D21C 9/08(2006.01) D21H 17/37(2006.01) D21C 9/10(2006.01) D21H 21/02(2006.01) (52) Cooperative Patent Classification (CPC): D21H 21/02; D21C 9/10; D21C 9/086; D21H 17/375 (86) International application number: PCT/FI2021/050441 (87) International publication number: WO 2021/255335 (23.12.2021 Gazette 2021/51)

(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 MK MT NL NO PL PT RO RS SE SI SK SM TR Designated Extension States: BA ME Designated Validation States: KH MA MD TN (30) Priority: 16.06.2020 FI 20205630 (71) Applicant: Kemira OYJ Helsinki 00180 (FI)	(72) Inventors: ROBERTSEN, Leif 21600 Parainen (FI) KONN, Jonas 02270 Espoo (FI) (74) Representative: Berggren Oy  P.O. Box 16 Eteläinen Rautatiekatu 10A 00101 Helsinki 00101 Helsinki (FI)