CA2157109C - Method of bleaching pulp with chlorine-free chemicals - Google Patents
Method of bleaching pulp with chlorine-free chemicals Download PDFInfo
- Publication number
- CA2157109C CA2157109C CA002157109A CA2157109A CA2157109C CA 2157109 C CA2157109 C CA 2157109C CA 002157109 A CA002157109 A CA 002157109A CA 2157109 A CA2157109 A CA 2157109A CA 2157109 C CA2157109 C CA 2157109C
- Authority
- CA
- Canada
- Prior art keywords
- stage
- pulp
- recited
- bleaching
- ozone
- Prior art date
- Legal status (The legal status is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the status listed.)
- Expired - Fee Related
Links
- 238000004061 bleaching Methods 0.000 title claims abstract description 68
- 238000000034 method Methods 0.000 title claims description 44
- 239000000126 substance Substances 0.000 title claims description 24
- CBENFWSGALASAD-UHFFFAOYSA-N Ozone Chemical compound [O-][O+]=O CBENFWSGALASAD-UHFFFAOYSA-N 0.000 claims abstract description 46
- 229910001385 heavy metal Inorganic materials 0.000 claims abstract description 28
- 150000002978 peroxides Chemical class 0.000 claims abstract description 24
- QVGXLLKOCUKJST-UHFFFAOYSA-N atomic oxygen Chemical compound [O] QVGXLLKOCUKJST-UHFFFAOYSA-N 0.000 claims abstract description 23
- 239000001301 oxygen Substances 0.000 claims abstract description 23
- 229910052760 oxygen Inorganic materials 0.000 claims abstract description 23
- 239000002655 kraft paper Substances 0.000 claims abstract description 9
- 239000000706 filtrate Substances 0.000 claims description 36
- 238000005406 washing Methods 0.000 claims description 34
- 238000012216 screening Methods 0.000 claims description 20
- 239000002253 acid Substances 0.000 claims description 19
- 239000003513 alkali Substances 0.000 claims description 15
- 239000011777 magnesium Substances 0.000 claims description 14
- FYYHWMGAXLPEAU-UHFFFAOYSA-N Magnesium Chemical compound [Mg] FYYHWMGAXLPEAU-UHFFFAOYSA-N 0.000 claims description 12
- 229910052749 magnesium Inorganic materials 0.000 claims description 12
- 102000004190 Enzymes Human genes 0.000 claims description 7
- 108090000790 Enzymes Proteins 0.000 claims description 7
- 229910052751 metal Inorganic materials 0.000 claims description 7
- 239000002184 metal Substances 0.000 claims description 7
- ZAMOUSCENKQFHK-UHFFFAOYSA-N Chlorine atom Chemical compound [Cl] ZAMOUSCENKQFHK-UHFFFAOYSA-N 0.000 claims description 6
- 239000000460 chlorine Substances 0.000 claims description 6
- 229910052801 chlorine Inorganic materials 0.000 claims description 6
- 238000000605 extraction Methods 0.000 claims description 6
- 150000002739 metals Chemical class 0.000 claims description 3
- PWHULOQIROXLJO-UHFFFAOYSA-N Manganese Chemical compound [Mn] PWHULOQIROXLJO-UHFFFAOYSA-N 0.000 claims description 2
- 229910052748 manganese Inorganic materials 0.000 claims description 2
- 239000011572 manganese Substances 0.000 claims description 2
- 239000002738 chelating agent Substances 0.000 claims 3
- 230000002378 acidificating effect Effects 0.000 claims 2
- 239000002657 fibrous material Substances 0.000 claims 2
- 238000007865 diluting Methods 0.000 claims 1
- 238000004519 manufacturing process Methods 0.000 abstract description 2
- 150000002894 organic compounds Chemical class 0.000 abstract 1
- 238000006243 chemical reaction Methods 0.000 description 12
- 230000008569 process Effects 0.000 description 8
- 238000004140 cleaning Methods 0.000 description 7
- 238000010411 cooking Methods 0.000 description 4
- 239000007789 gas Substances 0.000 description 4
- KCXVZYZYPLLWCC-UHFFFAOYSA-N EDTA Chemical compound OC(=O)CN(CC(O)=O)CCN(CC(O)=O)CC(O)=O KCXVZYZYPLLWCC-UHFFFAOYSA-N 0.000 description 3
- HEMHJVSKTPXQMS-UHFFFAOYSA-M Sodium hydroxide Chemical compound [OH-].[Na+] HEMHJVSKTPXQMS-UHFFFAOYSA-M 0.000 description 3
- 239000000835 fiber Substances 0.000 description 3
- 229910052943 magnesium sulfate Inorganic materials 0.000 description 3
- 238000011084 recovery Methods 0.000 description 3
- 239000000725 suspension Substances 0.000 description 3
- 230000008719 thickening Effects 0.000 description 3
- XLYOFNOQVPJJNP-UHFFFAOYSA-N water Substances O XLYOFNOQVPJJNP-UHFFFAOYSA-N 0.000 description 3
- CSNNHWWHGAXBCP-UHFFFAOYSA-L Magnesium sulfate Chemical compound [Mg+2].[O-][S+2]([O-])([O-])[O-] CSNNHWWHGAXBCP-UHFFFAOYSA-L 0.000 description 2
- 239000012159 carrier gas Substances 0.000 description 2
- 238000005352 clarification Methods 0.000 description 2
- 150000001875 compounds Chemical class 0.000 description 2
- 230000003247 decreasing effect Effects 0.000 description 2
- 238000010790 dilution Methods 0.000 description 2
- 239000012895 dilution Substances 0.000 description 2
- OSVXSBDYLRYLIG-UHFFFAOYSA-N dioxidochlorine(.) Chemical compound O=Cl=O OSVXSBDYLRYLIG-UHFFFAOYSA-N 0.000 description 2
- 238000002474 experimental method Methods 0.000 description 2
- 238000010438 heat treatment Methods 0.000 description 2
- 230000007935 neutral effect Effects 0.000 description 2
- 230000001590 oxidative effect Effects 0.000 description 2
- 239000002562 thickening agent Substances 0.000 description 2
- 235000018185 Betula X alpestris Nutrition 0.000 description 1
- 235000018212 Betula X uliginosa Nutrition 0.000 description 1
- KZBUYRJDOAKODT-UHFFFAOYSA-N Chlorine Chemical compound ClCl KZBUYRJDOAKODT-UHFFFAOYSA-N 0.000 description 1
- 239000004155 Chlorine dioxide Substances 0.000 description 1
- 230000004913 activation Effects 0.000 description 1
- 238000010420 art technique Methods 0.000 description 1
- 230000033228 biological regulation Effects 0.000 description 1
- 239000007844 bleaching agent Substances 0.000 description 1
- 239000007795 chemical reaction product Substances 0.000 description 1
- 235000019398 chlorine dioxide Nutrition 0.000 description 1
- 239000008139 complexing agent Substances 0.000 description 1
- 238000005260 corrosion Methods 0.000 description 1
- 230000007797 corrosion Effects 0.000 description 1
- 238000009826 distribution Methods 0.000 description 1
- 239000012467 final product Substances 0.000 description 1
- 239000013505 freshwater Substances 0.000 description 1
- 229920005610 lignin Polymers 0.000 description 1
- 235000019341 magnesium sulphate Nutrition 0.000 description 1
- 150000001455 metallic ions Chemical class 0.000 description 1
- 239000000203 mixture Substances 0.000 description 1
- 238000012986 modification Methods 0.000 description 1
- 230000004048 modification Effects 0.000 description 1
- 150000004045 organic chlorine compounds Chemical class 0.000 description 1
- 238000012545 processing Methods 0.000 description 1
- 239000000047 product Substances 0.000 description 1
- 230000001681 protective effect Effects 0.000 description 1
- 238000004076 pulp bleaching Methods 0.000 description 1
- 230000003134 recirculating effect Effects 0.000 description 1
- 238000011160 research Methods 0.000 description 1
- 239000011122 softwood Substances 0.000 description 1
- 238000012360 testing method Methods 0.000 description 1
- 229910021654 trace metal Inorganic materials 0.000 description 1
- 239000003643 water by type Substances 0.000 description 1
Classifications
-
- D—TEXTILES; PAPER
- D21—PAPER-MAKING; PRODUCTION OF CELLULOSE
- D21C—PRODUCTION OF CELLULOSE BY REMOVING NON-CELLULOSE SUBSTANCES FROM CELLULOSE-CONTAINING MATERIALS; REGENERATION OF PULPING LIQUORS; APPARATUS THEREFOR
- D21C9/00—After-treatment of cellulose pulp, e.g. of wood pulp, or cotton linters ; Treatment of dilute or dewatered pulp or process improvement taking place after obtaining the raw cellulosic material and not provided for elsewhere
- D21C9/10—Bleaching ; Apparatus therefor
- D21C9/1026—Other features in bleaching processes
-
- D—TEXTILES; PAPER
- D21—PAPER-MAKING; PRODUCTION OF CELLULOSE
- D21C—PRODUCTION OF CELLULOSE BY REMOVING NON-CELLULOSE SUBSTANCES FROM CELLULOSE-CONTAINING MATERIALS; REGENERATION OF PULPING LIQUORS; APPARATUS THEREFOR
- D21C9/00—After-treatment of cellulose pulp, e.g. of wood pulp, or cotton linters ; Treatment of dilute or dewatered pulp or process improvement taking place after obtaining the raw cellulosic material and not provided for elsewhere
- D21C9/02—Washing ; Displacing cooking or pulp-treating liquors contained in the pulp by fluids, e.g. wash water or other pulp-treating agents
-
- D—TEXTILES; PAPER
- D21—PAPER-MAKING; PRODUCTION OF CELLULOSE
- D21C—PRODUCTION OF CELLULOSE BY REMOVING NON-CELLULOSE SUBSTANCES FROM CELLULOSE-CONTAINING MATERIALS; REGENERATION OF PULPING LIQUORS; APPARATUS THEREFOR
- D21C9/00—After-treatment of cellulose pulp, e.g. of wood pulp, or cotton linters ; Treatment of dilute or dewatered pulp or process improvement taking place after obtaining the raw cellulosic material and not provided for elsewhere
- D21C9/10—Bleaching ; Apparatus therefor
- D21C9/1026—Other features in bleaching processes
- D21C9/1036—Use of compounds accelerating or improving the efficiency of the processes
-
- D—TEXTILES; PAPER
- D21—PAPER-MAKING; PRODUCTION OF CELLULOSE
- D21C—PRODUCTION OF CELLULOSE BY REMOVING NON-CELLULOSE SUBSTANCES FROM CELLULOSE-CONTAINING MATERIALS; REGENERATION OF PULPING LIQUORS; APPARATUS THEREFOR
- D21C9/00—After-treatment of cellulose pulp, e.g. of wood pulp, or cotton linters ; Treatment of dilute or dewatered pulp or process improvement taking place after obtaining the raw cellulosic material and not provided for elsewhere
- D21C9/10—Bleaching ; Apparatus therefor
- D21C9/1026—Other features in bleaching processes
- D21C9/1042—Use of chelating agents
-
- D—TEXTILES; PAPER
- D21—PAPER-MAKING; PRODUCTION OF CELLULOSE
- D21C—PRODUCTION OF CELLULOSE BY REMOVING NON-CELLULOSE SUBSTANCES FROM CELLULOSE-CONTAINING MATERIALS; REGENERATION OF PULPING LIQUORS; APPARATUS THEREFOR
- D21C9/00—After-treatment of cellulose pulp, e.g. of wood pulp, or cotton linters ; Treatment of dilute or dewatered pulp or process improvement taking place after obtaining the raw cellulosic material and not provided for elsewhere
- D21C9/10—Bleaching ; Apparatus therefor
- D21C9/1057—Multistage, with compounds cited in more than one sub-group D21C9/10, D21C9/12, D21C9/16
-
- D—TEXTILES; PAPER
- D21—PAPER-MAKING; PRODUCTION OF CELLULOSE
- D21C—PRODUCTION OF CELLULOSE BY REMOVING NON-CELLULOSE SUBSTANCES FROM CELLULOSE-CONTAINING MATERIALS; REGENERATION OF PULPING LIQUORS; APPARATUS THEREFOR
- D21C9/00—After-treatment of cellulose pulp, e.g. of wood pulp, or cotton linters ; Treatment of dilute or dewatered pulp or process improvement taking place after obtaining the raw cellulosic material and not provided for elsewhere
- D21C9/10—Bleaching ; Apparatus therefor
- D21C9/147—Bleaching ; Apparatus therefor with oxygen or its allotropic modifications
-
- D—TEXTILES; PAPER
- D21—PAPER-MAKING; PRODUCTION OF CELLULOSE
- D21C—PRODUCTION OF CELLULOSE BY REMOVING NON-CELLULOSE SUBSTANCES FROM CELLULOSE-CONTAINING MATERIALS; REGENERATION OF PULPING LIQUORS; APPARATUS THEREFOR
- D21C9/00—After-treatment of cellulose pulp, e.g. of wood pulp, or cotton linters ; Treatment of dilute or dewatered pulp or process improvement taking place after obtaining the raw cellulosic material and not provided for elsewhere
- D21C9/10—Bleaching ; Apparatus therefor
- D21C9/147—Bleaching ; Apparatus therefor with oxygen or its allotropic modifications
- D21C9/153—Bleaching ; Apparatus therefor with oxygen or its allotropic modifications with ozone
-
- D—TEXTILES; PAPER
- D21—PAPER-MAKING; PRODUCTION OF CELLULOSE
- D21C—PRODUCTION OF CELLULOSE BY REMOVING NON-CELLULOSE SUBSTANCES FROM CELLULOSE-CONTAINING MATERIALS; REGENERATION OF PULPING LIQUORS; APPARATUS THEREFOR
- D21C9/00—After-treatment of cellulose pulp, e.g. of wood pulp, or cotton linters ; Treatment of dilute or dewatered pulp or process improvement taking place after obtaining the raw cellulosic material and not provided for elsewhere
- D21C9/10—Bleaching ; Apparatus therefor
- D21C9/16—Bleaching ; Apparatus therefor with per compounds
- D21C9/163—Bleaching ; Apparatus therefor with per compounds with peroxides
Landscapes
- Life Sciences & Earth Sciences (AREA)
- Engineering & Computer Science (AREA)
- Wood Science & Technology (AREA)
- Paper (AREA)
- Detergent Compositions (AREA)
- Coloring Foods And Improving Nutritive Qualities (AREA)
- Organic Low-Molecular-Weight Compounds And Preparation Thereof (AREA)
Applications Claiming Priority (3)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| FI930954A FI93232C (fi) | 1993-03-03 | 1993-03-03 | Menetelmä massan valkaisemiseksi kloorivapailla kemikaaleilla |
| FI930954 | 1993-03-03 | ||
| PCT/FI1993/000222 WO1994020673A1 (en) | 1993-03-03 | 1993-05-25 | Method of bleaching pulp with chlorine-free chemicals |
Publications (2)
| Publication Number | Publication Date |
|---|---|
| CA2157109A1 CA2157109A1 (en) | 1994-09-15 |
| CA2157109C true CA2157109C (en) | 2002-09-03 |
Family
ID=8537491
Family Applications (1)
| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| CA002157109A Expired - Fee Related CA2157109C (en) | 1993-03-03 | 1993-05-25 | Method of bleaching pulp with chlorine-free chemicals |
Country Status (13)
| Country | Link |
|---|---|
| EP (2) | EP0687321B1 (de) |
| JP (1) | JP3276083B2 (de) |
| AT (2) | ATE228181T1 (de) |
| AU (1) | AU5370594A (de) |
| BR (1) | BR9307858A (de) |
| CA (1) | CA2157109C (de) |
| DE (2) | DE69323566T2 (de) |
| ES (2) | ES2186948T3 (de) |
| FI (3) | FI93232C (de) |
| NO (1) | NO953444L (de) |
| PT (1) | PT884415E (de) |
| RU (1) | RU2126471C1 (de) |
| WO (1) | WO1994020673A1 (de) |
Families Citing this family (17)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| FI89516B (fi) | 1989-05-10 | 1993-06-30 | Ahlstroem Oy | Foerfarande foer blekning av cellulosamassa med otson |
| FI103818B1 (fi) * | 1995-02-21 | 1999-09-30 | Ahlstrom Machinery Oy | Menetelmä massan valkaisemiseksi |
| US20080110584A1 (en) * | 2006-11-15 | 2008-05-15 | Caifang Yin | Bleaching process with at least one extraction stage |
| FR2910027B1 (fr) * | 2006-12-13 | 2009-11-06 | Itt Mfg Enterprises Inc | Procede de blanchiment des pates papeteries chimiques par traitement final a l'ozone a haute temperature |
| FI119062B (fi) * | 2006-12-28 | 2008-07-15 | Upm Kymmene Corp | Menetelmä mekaanisen massan valmistamiseksi |
| MX382645B (es) | 2009-05-28 | 2025-03-13 | Gp Cellulose Gmbh | Celulosa modificada a partir de fibra kraft química y métodos para elaborarla y su uso. |
| WO2012170183A1 (en) | 2011-05-23 | 2012-12-13 | Gp Cellulose Gmbh | Softwood kraft fiber having improved whiteness and brightness and methods of making and using the same |
| TWI628331B (zh) | 2012-01-12 | 2018-07-01 | Ｇｐ纖維股份有限公司 | 具有降低黃化性質之低黏度牛皮紙纖維及其製造與使用方法 |
| JP6242859B2 (ja) | 2012-04-18 | 2017-12-06 | ゲーペー ツェルローゼ ゲーエムベーハー | ビスコースおよび他の二次的繊維製品の製造のための、パルプを処理して、クラフトパルプの繊維への取り込みを改良するための界面活性剤の使用 |
| CA2898417C (en) | 2013-02-08 | 2021-07-27 | Arthur J. Nonni | Softwood kraft fiber having an improved .alpha.-cellulose content and its use in the production of chemical cellulose products |
| MX364379B (es) | 2013-03-14 | 2019-04-24 | Gp Cellulose Gmbh | Un metodo para preparar una fibra kraft altamente funcional y de baja viscosidad, usando una secuencia de blanqueamiento acido, y una fibra hecha por el proceso. |
| CN105143547B (zh) | 2013-03-15 | 2018-05-01 | Gp 纤维素股份有限公司 | 具有增高羧基含量的低粘度牛皮纸纤维及其制造和使用方法 |
| FR3007044B1 (fr) * | 2013-06-13 | 2016-01-15 | Air Liquide | Procede de traitement des pates papetieres chimiques par traitement a l'ozone en presence d'ions magnesium |
| AT515152B1 (de) * | 2013-11-26 | 2015-12-15 | Chemiefaser Lenzing Ag | Verfahren zum Vorbehandeln von rückgewonnenen Baumwollfasern zur Verwendung bei der Herstellung von Formkörpern aus regenerierter Cellulose |
| WO2018093697A1 (en) | 2016-11-16 | 2018-05-24 | Gp Cellulose Gmbh | Modified cellulose from chemical fiber and methods of making and using the same |
| SE2051513A1 (en) * | 2020-12-21 | 2022-03-08 | Valmet Oy | Method for bleaching pulp from recycled textile material |
| SE545759C2 (en) * | 2022-06-20 | 2024-01-02 | Valmet Oy | Method for bleaching pulp from recycled textile material |
Family Cites Families (9)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| NO144711C (no) | 1978-04-04 | 1981-10-21 | Myrens Verksted As | Fremgangsmaate til bleking av oksygendelignifiserte celluloseholdige masser med ozon |
| US4310384A (en) * | 1979-01-11 | 1982-01-12 | Weyerhaeuser Company | Reducing chemical transfer between treatment stages |
| FI74752C (fi) * | 1986-03-20 | 1992-12-01 | Ahlstroem Oy | Foerfarande och anordning foer tvaettning av cellulosa |
| DE69004492T3 (de) * | 1989-06-06 | 2001-11-15 | Eka Nobel Ab, Bohus | Verfahren zum Bleichen von Lignocellulose enthaltenden Zellstoffen. |
| SU1675451A1 (ru) * | 1989-09-25 | 1991-09-07 | Центральный научно-исследовательский институт бумаги | Способ подготовки волокнистого полуфабриката к отливу бумажного полотна при изготовлении бумаги |
| AU636173B2 (en) * | 1989-10-30 | 1993-04-22 | Lenzing Aktiengesellschaft | Method for the chlorine-free bleaching of pulps |
| US5567262A (en) * | 1991-04-16 | 1996-10-22 | Ahlstrom Machinery Inc. | Two stage pressure diffuser |
| SE468355B (sv) * | 1991-04-30 | 1992-12-21 | Eka Nobel Ab | Blekning av kemisk massa genom behandling med komplexbildare och ozon |
| AT400153B (de) * | 1991-05-02 | 1995-10-25 | Voest Alpine Ind Anlagen | Verfahren zum bleichen von xylan- und lignocellulosehältigen materialien |
-
1993
- 1993-03-03 FI FI930954A patent/FI93232C/fi active
- 1993-05-25 AT AT98113684T patent/ATE228181T1/de not_active IP Right Cessation
- 1993-05-25 RU RU95122814A patent/RU2126471C1/ru active
- 1993-05-25 JP JP51962394A patent/JP3276083B2/ja not_active Expired - Fee Related
- 1993-05-25 EP EP93910051A patent/EP0687321B1/de not_active Expired - Lifetime
- 1993-05-25 ES ES98113684T patent/ES2186948T3/es not_active Expired - Lifetime
- 1993-05-25 WO PCT/FI1993/000222 patent/WO1994020673A1/en not_active Ceased
- 1993-05-25 AT AT93910051T patent/ATE176808T1/de not_active IP Right Cessation
- 1993-05-25 DE DE69323566T patent/DE69323566T2/de not_active Expired - Fee Related
- 1993-05-25 BR BR9307858A patent/BR9307858A/pt not_active IP Right Cessation
- 1993-05-25 CA CA002157109A patent/CA2157109C/en not_active Expired - Fee Related
- 1993-05-25 FI FI954093A patent/FI954093A7/fi not_active IP Right Cessation
- 1993-05-25 EP EP98113684A patent/EP0884415B1/de not_active Expired - Lifetime
- 1993-05-25 PT PT98113684T patent/PT884415E/pt unknown
- 1993-05-25 AU AU53705/94A patent/AU5370594A/en not_active Abandoned
- 1993-05-25 DE DE69332508T patent/DE69332508T2/de not_active Expired - Fee Related
- 1993-05-25 ES ES93910051T patent/ES2130260T3/es not_active Expired - Lifetime
- 1993-09-15 FI FI934036A patent/FI98223B/fi not_active IP Right Cessation
-
1995
- 1995-09-01 NO NO953444A patent/NO953444L/no unknown
Also Published As
| Publication number | Publication date |
|---|---|
| FI934036A0 (fi) | 1993-09-15 |
| FI93232B (fi) | 1994-11-30 |
| AU5370594A (en) | 1994-09-26 |
| ATE228181T1 (de) | 2002-12-15 |
| FI98223B (fi) | 1997-01-31 |
| DE69332508T2 (de) | 2003-07-03 |
| ES2186948T3 (es) | 2003-05-16 |
| ATE176808T1 (de) | 1999-03-15 |
| FI930954L (fi) | 1994-09-04 |
| BR9307858A (pt) | 1996-02-27 |
| FI930954A0 (fi) | 1993-03-03 |
| DE69332508D1 (de) | 2003-01-02 |
| FI934036L (fi) | 1994-09-04 |
| DE69323566T2 (de) | 1999-07-15 |
| CA2157109A1 (en) | 1994-09-15 |
| EP0687321B1 (de) | 1999-02-17 |
| FI954093A0 (fi) | 1995-08-30 |
| NO953444D0 (no) | 1995-09-01 |
| NO953444L (no) | 1995-10-19 |
| DE69323566D1 (de) | 1999-03-25 |
| EP0687321A1 (de) | 1995-12-20 |
| FI93232C (fi) | 1995-03-10 |
| EP0884415B1 (de) | 2002-11-20 |
| JPH08509781A (ja) | 1996-10-15 |
| ES2130260T3 (es) | 1999-07-01 |
| PT884415E (pt) | 2003-03-31 |
| RU2126471C1 (ru) | 1999-02-20 |
| JP3276083B2 (ja) | 2002-04-22 |
| EP0884415A1 (de) | 1998-12-16 |
| FI954093A7 (fi) | 1995-10-17 |
| WO1994020673A1 (en) | 1994-09-15 |
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Legal Events
| Date | Code | Title | Description |
|---|---|---|---|
| EEER | Examination request | ||
| MKLA | Lapsed |