CH634362A5 - Process for the manufacture of chemical papermaking pulps - Google Patents

Process for the manufacture of chemical papermaking pulps Download PDF

Info

Publication number: CH634362A5
Authority: CH; Switzerland
Prior art keywords: cooking; stage; weight; peroxide; sodium hydroxide
Prior art date: 1977-07-29

Application number

CH815678A

Other languages

English (en)

French (fr)

Inventor

Dominique Lachenal

Christian De Choudens

Pierre Monzie

Original Assignee

Ugine Kuhlmann

Priority date (The priority date 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 date listed.)

1977-07-29

Filing date

1978-07-28

Publication date

1983-01-31

1977-07-29 Priority claimed from FR7724131A external-priority patent/FR2398839A1/fr

1978-07-05 Priority claimed from FR7820715A external-priority patent/FR2430475A2/fr

1978-07-28 Application filed by Ugine Kuhlmann filed Critical Ugine Kuhlmann

1983-01-31 Publication of CH634362A5 publication Critical patent/CH634362A5/fr

Links

238000000034 method Methods 0.000 title claims description 72
230000008569 process Effects 0.000 title claims description 49
238000004519 manufacturing process Methods 0.000 title claims description 9
239000000126 substance Substances 0.000 title claims description 5
HEMHJVSKTPXQMS-UHFFFAOYSA-M Sodium hydroxide Chemical compound [OH-].[Na+] HEMHJVSKTPXQMS-UHFFFAOYSA-M 0.000 claims description 99
238000010411 cooking Methods 0.000 claims description 56
150000002978 peroxides Chemical class 0.000 claims description 36
MHAJPDPJQMAIIY-UHFFFAOYSA-N Hydrogen peroxide Chemical compound OO MHAJPDPJQMAIIY-UHFFFAOYSA-N 0.000 claims description 26
229920001131 Pulp (paper) Polymers 0.000 claims description 12
239000000463 material Substances 0.000 claims description 12
PYKYMHQGRFAEBM-UHFFFAOYSA-N anthraquinone Natural products CCC(=O)c1c(O)c2C(=O)C3C(C=CC=C3O)C(=O)c2cc1CC(=O)OC PYKYMHQGRFAEBM-UHFFFAOYSA-N 0.000 claims description 10
150000004056 anthraquinones Chemical class 0.000 claims description 10
239000000243 solution Substances 0.000 claims description 8
239000002671 adjuvant Substances 0.000 claims description 7
239000012670 alkaline solution Substances 0.000 claims description 7
239000012978 lignocellulosic material Substances 0.000 claims description 7
239000003381 stabilizer Substances 0.000 claims description 6
239000000835 fiber Substances 0.000 claims description 5
-1 aromatic nitro derivatives Chemical class 0.000 claims description 4
150000003997 cyclic ketones Chemical class 0.000 claims description 3
RZVHIXYEVGDQDX-UHFFFAOYSA-N 9,10-anthraquinone Chemical group C1=CC=C2C(=O)C3=CC=CC=C3C(=O)C2=C1 RZVHIXYEVGDQDX-UHFFFAOYSA-N 0.000 claims 1
239000003513 alkali Substances 0.000 claims 1
229910017464 nitrogen compound Inorganic materials 0.000 claims 1
125000001791 phenazinyl group Chemical group C1(=CC=CC2=NC3=CC=CC=C3N=C12)* 0.000 claims 1
239000002655 kraft paper Substances 0.000 description 30
239000001301 oxygen Substances 0.000 description 17
229910052760 oxygen Inorganic materials 0.000 description 17
CDBYLPFSWZWCQE-UHFFFAOYSA-L Sodium Carbonate Chemical compound [Na+].[Na+].[O-]C([O-])=O CDBYLPFSWZWCQE-UHFFFAOYSA-L 0.000 description 15
QVGXLLKOCUKJST-UHFFFAOYSA-N atomic oxygen Chemical compound [O] QVGXLLKOCUKJST-UHFFFAOYSA-N 0.000 description 14
OSVXSBDYLRYLIG-UHFFFAOYSA-N dioxidochlorine(.) Chemical compound O=Cl=O OSVXSBDYLRYLIG-UHFFFAOYSA-N 0.000 description 14
239000003153 chemical reaction reagent Substances 0.000 description 13
230000008901 benefit Effects 0.000 description 11
UDHXJZHVNHGCEC-UHFFFAOYSA-N Chlorophacinone Chemical compound C1=CC(Cl)=CC=C1C(C=1C=CC=CC=1)C(=O)C1C(=O)C2=CC=CC=C2C1=O UDHXJZHVNHGCEC-UHFFFAOYSA-N 0.000 description 8
241000196324 Embryophyta Species 0.000 description 8
238000011282 treatment Methods 0.000 description 8
239000004155 Chlorine dioxide Substances 0.000 description 7
238000004061 bleaching Methods 0.000 description 7
239000003795 chemical substances by application Substances 0.000 description 7
235000019398 chlorine dioxide Nutrition 0.000 description 7
CSNNHWWHGAXBCP-UHFFFAOYSA-L Magnesium sulfate Chemical compound [Mg+2].[O-][S+2]([O-])([O-])[O-] CSNNHWWHGAXBCP-UHFFFAOYSA-L 0.000 description 6
235000015927 pasta Nutrition 0.000 description 6
230000009471 action Effects 0.000 description 5
239000007844 bleaching agent Substances 0.000 description 5
150000001875 compounds Chemical class 0.000 description 5
239000000123 paper Substances 0.000 description 5
239000002023 wood Substances 0.000 description 5
ZAMOUSCENKQFHK-UHFFFAOYSA-N Chlorine atom Chemical compound [Cl] ZAMOUSCENKQFHK-UHFFFAOYSA-N 0.000 description 4
241001236212 Pinus pinaster Species 0.000 description 4
235000005105 Pinus pinaster Nutrition 0.000 description 4
239000004115 Sodium Silicate Substances 0.000 description 4
RAHZWNYVWXNFOC-UHFFFAOYSA-N Sulphur dioxide Chemical compound O=S=O RAHZWNYVWXNFOC-UHFFFAOYSA-N 0.000 description 4
239000000460 chlorine Substances 0.000 description 4
229910052801 chlorine Inorganic materials 0.000 description 4
238000000354 decomposition reaction Methods 0.000 description 4
229910052911 sodium silicate Inorganic materials 0.000 description 4
239000011122 softwood Substances 0.000 description 4
239000002253 acid Substances 0.000 description 3
239000000654 additive Substances 0.000 description 3
RAXXELZNTBOGNW-UHFFFAOYSA-N imidazole Natural products C1=CNC=N1 RAXXELZNTBOGNW-UHFFFAOYSA-N 0.000 description 3
229920005610 lignin Polymers 0.000 description 3
229910052943 magnesium sulfate Inorganic materials 0.000 description 3
235000019341 magnesium sulphate Nutrition 0.000 description 3
229910052751 metal Inorganic materials 0.000 description 3
239000002184 metal Substances 0.000 description 3
230000001590 oxidative effect Effects 0.000 description 3
239000002994 raw material Substances 0.000 description 3
229910000029 sodium carbonate Inorganic materials 0.000 description 3
NTHWMYGWWRZVTN-UHFFFAOYSA-N sodium silicate Chemical compound [Na+].[Na+].[O-][Si]([O-])=O NTHWMYGWWRZVTN-UHFFFAOYSA-N 0.000 description 3
241000894007 species Species 0.000 description 3
230000002087 whitening effect Effects 0.000 description 3
VEPOHXYIFQMVHW-XOZOLZJESA-N 2,3-dihydroxybutanedioic acid (2S,3S)-3,4-dimethyl-2-phenylmorpholine Chemical compound OC(C(O)C(O)=O)C(O)=O.C[C@H]1[C@@H](OCCN1C)c1ccccc1 VEPOHXYIFQMVHW-XOZOLZJESA-N 0.000 description 2
RWSOTUBLDIXVET-UHFFFAOYSA-N Dihydrogen sulfide Chemical class S RWSOTUBLDIXVET-UHFFFAOYSA-N 0.000 description 2
240000000731 Fagus sylvatica Species 0.000 description 2
235000010099 Fagus sylvatica Nutrition 0.000 description 2
FZERHIULMFGESH-UHFFFAOYSA-N N-phenylacetamide Chemical compound CC(=O)NC1=CC=CC=C1 FZERHIULMFGESH-UHFFFAOYSA-N 0.000 description 2
KFSLWBXXFJQRDL-UHFFFAOYSA-N Peracetic acid Chemical compound CC(=O)OO KFSLWBXXFJQRDL-UHFFFAOYSA-N 0.000 description 2
PCNDJXKNXGMECE-UHFFFAOYSA-N Phenazine Natural products C1=CC=CC2=NC3=CC=CC=C3N=C21 PCNDJXKNXGMECE-UHFFFAOYSA-N 0.000 description 2
241000218657 Picea Species 0.000 description 2
ZLMJMSJWJFRBEC-UHFFFAOYSA-N Potassium Chemical compound [K] ZLMJMSJWJFRBEC-UHFFFAOYSA-N 0.000 description 2
VYPSYNLAJGMNEJ-UHFFFAOYSA-N Silicium dioxide Chemical compound O=[Si]=O VYPSYNLAJGMNEJ-UHFFFAOYSA-N 0.000 description 2
HNYOPLTXPVRDBG-UHFFFAOYSA-N barbituric acid Chemical compound O=C1CC(=O)NC(=O)N1 HNYOPLTXPVRDBG-UHFFFAOYSA-N 0.000 description 2
229920002678 cellulose Polymers 0.000 description 2
239000001913 cellulose Substances 0.000 description 2
239000000470 constituent Substances 0.000 description 2
230000000694 effects Effects 0.000 description 2
239000011121 hardwood Substances 0.000 description 2
238000009776 industrial production Methods 0.000 description 2
IJGRMHOSHXDMSA-UHFFFAOYSA-N nitrogen Substances N#N IJGRMHOSHXDMSA-UHFFFAOYSA-N 0.000 description 2
229910052757 nitrogen Inorganic materials 0.000 description 2
238000004806 packaging method and process Methods 0.000 description 2
239000011591 potassium Substances 0.000 description 2
229910052700 potassium Inorganic materials 0.000 description 2
230000009467 reduction Effects 0.000 description 2
150000004760 silicates Chemical class 0.000 description 2
PFUVRDFDKPNGAV-UHFFFAOYSA-N sodium peroxide Chemical compound [Na+].[Na+].[O-][O-] PFUVRDFDKPNGAV-UHFFFAOYSA-N 0.000 description 2
238000005406 washing Methods 0.000 description 2
GDALETGZDYOOGB-UHFFFAOYSA-N Acridone Natural products C1=C(O)C=C2N(C)C3=CC=CC=C3C(=O)C2=C1O GDALETGZDYOOGB-UHFFFAOYSA-N 0.000 description 1
241000609240 Ambelania acida Species 0.000 description 1
BVKZGUZCCUSVTD-UHFFFAOYSA-L Carbonate Chemical compound [O-]C([O-])=O BVKZGUZCCUSVTD-UHFFFAOYSA-L 0.000 description 1
241000726768 Carpinus Species 0.000 description 1
229920003043 Cellulose fiber Polymers 0.000 description 1
240000000797 Hibiscus cannabinus Species 0.000 description 1
DGAQECJNVWCQMB-PUAWFVPOSA-M Ilexoside XXIX Chemical compound C[C@@H]1CC[C@@]2(CC[C@@]3(C(=CC[C@H]4[C@]3(CC[C@@H]5[C@@]4(CC[C@@H](C5(C)C)OS(=O)(=O)[O-])C)C)[C@@H]2[C@]1(C)O)C)C(=O)O[C@H]6[C@@H]([C@H]([C@@H]([C@H](O6)CO)O)O)O.[Na+] DGAQECJNVWCQMB-PUAWFVPOSA-M 0.000 description 1
BPQQTUXANYXVAA-UHFFFAOYSA-N Orthosilicate Chemical compound [O-][Si]([O-])([O-])[O-] BPQQTUXANYXVAA-UHFFFAOYSA-N 0.000 description 1
235000008331 Pinus X rigitaeda Nutrition 0.000 description 1
235000011613 Pinus brutia Nutrition 0.000 description 1
241000018646 Pinus brutia Species 0.000 description 1
235000013431 Pinus clausa Nutrition 0.000 description 1
235000000773 Pinus glabra Nutrition 0.000 description 1
241001502813 Pinus glabra Species 0.000 description 1
WTKZEGDFNFYCGP-UHFFFAOYSA-N Pyrazole Chemical compound C=1C=NNC=1 WTKZEGDFNFYCGP-UHFFFAOYSA-N 0.000 description 1
229960001413 acetanilide Drugs 0.000 description 1
FZEYVTFCMJSGMP-UHFFFAOYSA-N acridone Chemical compound C1=CC=C2C(=O)C3=CC=CC=C3NC2=C1 FZEYVTFCMJSGMP-UHFFFAOYSA-N 0.000 description 1
230000001154 acute effect Effects 0.000 description 1
230000000996 additive effect Effects 0.000 description 1
239000008346 aqueous phase Substances 0.000 description 1
239000007864 aqueous solution Substances 0.000 description 1
239000010905 bagasse Substances 0.000 description 1
239000011230 binding agent Substances 0.000 description 1
239000006172 buffering agent Substances 0.000 description 1
LBAYFEDWGHXMSM-UHFFFAOYSA-N butaneperoxoic acid Chemical compound CCCC(=O)OO LBAYFEDWGHXMSM-UHFFFAOYSA-N 0.000 description 1
235000019402 calcium peroxide Nutrition 0.000 description 1
230000015556 catabolic process Effects 0.000 description 1
150000001768 cations Chemical class 0.000 description 1
239000008139 complexing agent Substances 0.000 description 1
238000006731 degradation reaction Methods 0.000 description 1
230000001627 detrimental effect Effects 0.000 description 1
230000008030 elimination Effects 0.000 description 1
238000003379 elimination reaction Methods 0.000 description 1
238000005265 energy consumption Methods 0.000 description 1
238000005516 engineering process Methods 0.000 description 1
230000007613 environmental effect Effects 0.000 description 1
238000004880 explosion Methods 0.000 description 1
230000002349 favourable effect Effects 0.000 description 1
239000012634 fragment Substances 0.000 description 1
239000007789 gas Substances 0.000 description 1
238000010438 heat treatment Methods 0.000 description 1
GPRLSGONYQIRFK-UHFFFAOYSA-N hydron Chemical compound [H+] GPRLSGONYQIRFK-UHFFFAOYSA-N 0.000 description 1
238000002513 implantation Methods 0.000 description 1
230000006872 improvement Effects 0.000 description 1
238000009434 installation Methods 0.000 description 1
238000010907 mechanical stirring Methods 0.000 description 1
229910021645 metal ion Inorganic materials 0.000 description 1
150000002739 metals Chemical class 0.000 description 1
239000000203 mixture Substances 0.000 description 1
230000003287 optical effect Effects 0.000 description 1
150000002894 organic compounds Chemical class 0.000 description 1
239000007800 oxidant agent Substances 0.000 description 1
JRKICGRDRMAZLK-UHFFFAOYSA-L persulfate group Chemical group S(=O)(=O)([O-])OOS(=O)(=O)[O-] JRKICGRDRMAZLK-UHFFFAOYSA-L 0.000 description 1
239000012071 phase Substances 0.000 description 1
238000007639 printing Methods 0.000 description 1
230000000135 prohibitive effect Effects 0.000 description 1
CZPZWMPYEINMCF-UHFFFAOYSA-N propaneperoxoic acid Chemical compound CCC(=O)OO CZPZWMPYEINMCF-UHFFFAOYSA-N 0.000 description 1
238000004076 pulp bleaching Methods 0.000 description 1
239000000376 reactant Substances 0.000 description 1
238000007670 refining Methods 0.000 description 1
230000001105 regulatory effect Effects 0.000 description 1
238000000926 separation method Methods 0.000 description 1
239000000377 silicon dioxide Substances 0.000 description 1
239000011734 sodium Substances 0.000 description 1
229910052708 sodium Inorganic materials 0.000 description 1
229960001922 sodium perborate Drugs 0.000 description 1
239000001488 sodium phosphate Substances 0.000 description 1
229910000162 sodium phosphate Inorganic materials 0.000 description 1
159000000000 sodium salts Chemical class 0.000 description 1
YKLJGMBLPUQQOI-UHFFFAOYSA-M sodium;oxidooxy(oxo)borane Chemical compound [Na+].[O-]OB=O YKLJGMBLPUQQOI-UHFFFAOYSA-M 0.000 description 1
230000000087 stabilizing effect Effects 0.000 description 1
239000010902 straw Substances 0.000 description 1
150000003464 sulfur compounds Chemical class 0.000 description 1
229910001428 transition metal ion Inorganic materials 0.000 description 1
RYFMWSXOAZQYPI-UHFFFAOYSA-K trisodium phosphate Chemical compound [Na+].[Na+].[Na+].[O-]P([O-])([O-])=O RYFMWSXOAZQYPI-UHFFFAOYSA-K 0.000 description 1
235000013311 vegetables Nutrition 0.000 description 1
XLYOFNOQVPJJNP-UHFFFAOYSA-N water Substances O XLYOFNOQVPJJNP-UHFFFAOYSA-N 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
- D21C3/00—Pulping cellulose-containing materials
- D21C3/22—Other features of pulping processes
- D21C3/26—Multistage processes

Landscapes

Paper (AREA)
Materials For Medical Uses (AREA)

CH815678A 1977-07-29 1978-07-28 Process for the manufacture of chemical papermaking pulps CH634362A5 (en)

Applications Claiming Priority (2)

Application Number	Priority Date	Filing Date	Title
FR7724131A FR2398839A1 (fr)	1977-07-29	1977-07-29	Procede de fabrication de pates papetieres chimiques
FR7820715A FR2430475A2 (fr)	1978-07-05	1978-07-05	Procede de fabrication de pates papetieres chimiques

Publications (1)

Publication Number	Publication Date
CH634362A5 true CH634362A5 (en)	1983-01-31

Family

ID=26220161

Family Applications (1)

Application Number	Title	Priority Date	Filing Date
CH815678A CH634362A5 (en)	1977-07-29	1978-07-28	Process for the manufacture of chemical papermaking pulps

Country Status (10)

Country	Link
AT (1)	AT371860B (de)
BE (1)	BE869153A (de)
CA (1)	CA1128260A (de)
CH (1)	CH634362A5 (de)
DE (1)	DE2833115C3 (de)
ES (1)	ES472184A1 (de)
FI (1)	FI70440C (de)
IT (1)	IT1160561B (de)
NO (1)	NO151975C (de)
SE (1)	SE439172B (de)

Families Citing this family (2)

* Cited by examiner, † Cited by third party
Publication number	Priority date	Publication date	Assignee	Title
FR2493365A1 (fr) *	1980-11-06	1982-05-07	Tech Ind Papiers Carton Centre	Procede pour la fabrication de pate papetiere chimique et pate ainsi obtenue
IT202000019033A1 (it) *	2020-08-03	2022-02-03	Davide Bertinazzo	Metodo per ottenere un precursore di un materiale ibrido legno-inorganico e metodo per ottenere un materiale ibrido legno-inorganico

Family Cites Families (3)

* Cited by examiner, † Cited by third party
Publication number	Priority date	Publication date	Assignee	Title
CA895756A (en) *	1970-04-03	1972-03-21	Macmillan Bloedel Limited	Two-stage soda-oxygen pulping
DE2327900C3 (de) *	1973-06-01	1985-02-07	Degussa Ag, 6000 Frankfurt	Bleichaufschluß von Zellstoff mit erheblich reduziertem Chloreinsatz
CA1073161A (en) *	1975-09-05	1980-03-11	Canadian Industries Limited	Delignification process

1978
- 1978-07-20 BE BE189399A patent/BE869153A/xx not_active IP Right Cessation
- 1978-07-26 NO NO78782573A patent/NO151975C/no unknown
- 1978-07-27 FI FI782342A patent/FI70440C/fi not_active IP Right Cessation
- 1978-07-27 CA CA308,295A patent/CA1128260A/fr not_active Expired
- 1978-07-27 AT AT0546578A patent/AT371860B/de not_active IP Right Cessation
- 1978-07-27 SE SE7808202A patent/SE439172B/sv not_active IP Right Cessation
- 1978-07-28 DE DE2833115A patent/DE2833115C3/de not_active Expired
- 1978-07-28 ES ES472184A patent/ES472184A1/es not_active Expired
- 1978-07-28 CH CH815678A patent/CH634362A5/fr not_active IP Right Cessation
- 1978-07-28 IT IT68812/78A patent/IT1160561B/it active

Also Published As

Publication number	Publication date
SE7808202L (sv)	1979-01-30
CA1128260A (fr)	1982-07-27
BE869153A (fr)	1979-01-22
SE439172B (sv)	1985-06-03
AT371860B (de)	1983-08-10
DE2833115B2 (de)	1980-07-03
DE2833115C3 (de)	1986-04-17
IT7868812A0 (it)	1978-07-28
FI70440C (fi)	1986-09-19
ES472184A1 (es)	1979-02-16
NO151975B (no)	1985-04-01
FI782342A7 (fi)	1979-01-30
FI70440B (fi)	1986-03-27
ATA546578A (de)	1982-12-15
DE2833115A1 (de)	1979-02-08
NO782573L (no)	1979-01-30
IT1160561B (it)	1987-03-11
NO151975C (no)	1985-07-10

Legal Events

Date	Code	Title	Description
1995-03-31	PL	Patent ceased
2024-10-31	PL	Patent ceased

Publication	Publication Date	Title
EP2761081B1 (de)	2018-08-08	Enzymatische vorbehandlung von holz in einem verfahren zur herstellung von mechanischem papierzellstoff
EP0018287B1 (de)	1983-01-12	Verfahren zur Delignifizierung von ungebleichtem chemischem Papierzellstoff
EP1322814B8 (de)	2011-05-25	Verfahren zum bleichen von zellstoff
EP2350381B1 (de)	2016-08-17	Verfahren zur herstellung von papierzellstoff
EP0925401A1 (de)	1999-06-30	Verfahren zum bleichen von papierzellstoff
CH418317A (fr)	1966-08-15	Procédé de fabrication de fibres de cellulose partiellement acétylées
BE1004674A3 (fr)	1993-01-12	Procede pour le blanchiment d'une pate a papier chimique et application de ce procede au blanchiment d'une pate kraft.
CH634362A5 (en)	1983-01-31	Process for the manufacture of chemical papermaking pulps
FR2743579A1 (fr)	1997-07-18	Procede de fabrication de pate a papier a partir de plantes lignocellulosiques et pate a papier obtenue
FR2634233A1 (fr)	1990-01-19	Procede de fabrication de pates chimicothermomecaniques blanchies
BE1004974A3 (fr)	1993-03-09	Procede pour le blanchiment et la delignification de pates a papier chimiques et application de ce procede au blanchiment et a la delignification des pates kraft et des pates asam.
WO2015104506A1 (fr)	2015-07-16	Compositions de peroxyde d'hydrogène pour la délignification de matière végétale et leurs utilisations
EP0213376B1 (de)	1990-10-10	Verfahren zur Delignifizierung von Zellulosematerialien
EP0190723A1 (de)	1986-08-13	Verfahren zur Verbesserung der mechanischen Eigenschaften einer chemischen oder halbchemischen Papierpulpe aus Bagasse
EP0728238B2 (de)	2004-08-11	Verfahren zum bleichen von zellstoff
EP0212329B1 (de)	1990-10-10	Verfahren zur Delignifizierung von Zellulosematerialien
BE1005800A3 (fr)	1994-02-01	Procede pour la delignification et le blanchiment d'une pate a papier chimique.
WO2000068495A1 (fr)	2000-11-16	Procede de blanchiment de pate a papier
BE1010617A3 (fr)	1998-11-03	Procede de blanchiment de pate a papier.
FR2552792A1 (fr)	1985-04-05	Procede perfectionne pour la production de pate de bois utilisant un additif derive de la s-triazine et pate de bois et papier ameliores contenant une s-triazine
BE1010677A3 (fr)	1998-11-03	Procede de delignification et de blanchiment de pate a papier chimique.
BE1010678A3 (fr)	1998-11-03	Procede de delignification et de blanchiment de pate a papier chimique.
CA1162008A (fr)	1984-02-14	Procede pour la fabrication de pate papetiere chimique et pate ainsi obtenue
BE656601A (de)	1964-12-31
BE492018A (de)