NO821525L - PROCEDURE FOR CHEMICAL PREPARATION OF CELLULOSE. - Google Patents
PROCEDURE FOR CHEMICAL PREPARATION OF CELLULOSE.Info
- Publication number
- NO821525L NO821525L NO821525A NO821525A NO821525L NO 821525 L NO821525 L NO 821525L NO 821525 A NO821525 A NO 821525A NO 821525 A NO821525 A NO 821525A NO 821525 L NO821525 L NO 821525L
- Authority
- NO
- Norway
- Prior art keywords
- cellulose
- ozone
- bleaching
- lignin
- procedure
- Prior art date
Links
- 229920002678 cellulose Polymers 0.000 title claims description 31
- 239000001913 cellulose Substances 0.000 title claims description 30
- 238000000034 method Methods 0.000 title claims description 18
- 239000000126 substance Substances 0.000 title description 5
- MWUXSHHQAYIFBG-UHFFFAOYSA-N Nitric oxide Chemical compound O=[N] MWUXSHHQAYIFBG-UHFFFAOYSA-N 0.000 claims description 32
- CBENFWSGALASAD-UHFFFAOYSA-N Ozone Chemical compound [O-][O+]=O CBENFWSGALASAD-UHFFFAOYSA-N 0.000 claims description 16
- 238000004061 bleaching Methods 0.000 claims description 10
- 239000003513 alkali Substances 0.000 claims description 7
- GRYLNZFGIOXLOG-UHFFFAOYSA-N Nitric acid Chemical compound O[N+]([O-])=O GRYLNZFGIOXLOG-UHFFFAOYSA-N 0.000 claims description 6
- 229910017604 nitric acid Inorganic materials 0.000 claims description 6
- 238000000605 extraction Methods 0.000 claims description 4
- 235000010980 cellulose Nutrition 0.000 description 25
- 229920005610 lignin Polymers 0.000 description 10
- HEMHJVSKTPXQMS-UHFFFAOYSA-M Sodium hydroxide Chemical compound [OH-].[Na+] HEMHJVSKTPXQMS-UHFFFAOYSA-M 0.000 description 6
- ZAMOUSCENKQFHK-UHFFFAOYSA-N Chlorine atom Chemical compound [Cl] ZAMOUSCENKQFHK-UHFFFAOYSA-N 0.000 description 4
- 239000007844 bleaching agent Substances 0.000 description 4
- 239000000460 chlorine Substances 0.000 description 4
- 229910052801 chlorine Inorganic materials 0.000 description 4
- LSNNMFCWUKXFEE-UHFFFAOYSA-L sulfite Chemical compound [O-]S([O-])=O LSNNMFCWUKXFEE-UHFFFAOYSA-L 0.000 description 4
- QAOWNCQODCNURD-UHFFFAOYSA-L Sulfate Chemical compound [O-]S([O-])(=O)=O QAOWNCQODCNURD-UHFFFAOYSA-L 0.000 description 3
- 239000007789 gas Substances 0.000 description 3
- 229910021653 sulphate ion Inorganic materials 0.000 description 3
- 238000005406 washing Methods 0.000 description 3
- 239000002351 wastewater Substances 0.000 description 3
- 239000002023 wood Substances 0.000 description 3
- OYPRJOBELJOOCE-UHFFFAOYSA-N Calcium Chemical compound [Ca] OYPRJOBELJOOCE-UHFFFAOYSA-N 0.000 description 2
- FYYHWMGAXLPEAU-UHFFFAOYSA-N Magnesium Chemical compound [Mg] FYYHWMGAXLPEAU-UHFFFAOYSA-N 0.000 description 2
- QVGXLLKOCUKJST-UHFFFAOYSA-N atomic oxygen Chemical compound [O] QVGXLLKOCUKJST-UHFFFAOYSA-N 0.000 description 2
- 238000009835 boiling Methods 0.000 description 2
- 239000011575 calcium Substances 0.000 description 2
- 229910052791 calcium Inorganic materials 0.000 description 2
- 239000003795 chemical substances by application Substances 0.000 description 2
- OSVXSBDYLRYLIG-UHFFFAOYSA-N dioxidochlorine(.) Chemical compound O=Cl=O OSVXSBDYLRYLIG-UHFFFAOYSA-N 0.000 description 2
- 230000007613 environmental effect Effects 0.000 description 2
- 239000000835 fiber Substances 0.000 description 2
- WQYVRQLZKVEZGA-UHFFFAOYSA-N hypochlorite Chemical compound Cl[O-] WQYVRQLZKVEZGA-UHFFFAOYSA-N 0.000 description 2
- 239000011777 magnesium Substances 0.000 description 2
- 229910052749 magnesium Inorganic materials 0.000 description 2
- 239000000463 material Substances 0.000 description 2
- 239000001301 oxygen Substances 0.000 description 2
- 229910052760 oxygen Inorganic materials 0.000 description 2
- 150000002978 peroxides Chemical class 0.000 description 2
- 239000004155 Chlorine dioxide Substances 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
- 241000218657 Picea Species 0.000 description 1
- 239000002253 acid Substances 0.000 description 1
- 238000010306 acid treatment Methods 0.000 description 1
- ZETCGWYACBNPIH-UHFFFAOYSA-N azane;sulfurous acid Chemical compound N.OS(O)=O ZETCGWYACBNPIH-UHFFFAOYSA-N 0.000 description 1
- 239000002585 base Substances 0.000 description 1
- 150000001720 carbohydrates Chemical class 0.000 description 1
- 235000014633 carbohydrates Nutrition 0.000 description 1
- 238000005660 chlorination reaction Methods 0.000 description 1
- 235000019398 chlorine dioxide Nutrition 0.000 description 1
- MAYPHUUCLRDEAZ-UHFFFAOYSA-N chlorine peroxide Inorganic materials ClOOCl MAYPHUUCLRDEAZ-UHFFFAOYSA-N 0.000 description 1
- 238000005352 clarification Methods 0.000 description 1
- 238000002485 combustion reaction Methods 0.000 description 1
- 150000001875 compounds Chemical class 0.000 description 1
- 238000010411 cooking Methods 0.000 description 1
- 238000005260 corrosion Methods 0.000 description 1
- 230000007797 corrosion Effects 0.000 description 1
- VDQVEACBQKUUSU-UHFFFAOYSA-M disodium;sulfanide Chemical compound [Na+].[Na+].[SH-] VDQVEACBQKUUSU-UHFFFAOYSA-M 0.000 description 1
- 239000004744 fabric Substances 0.000 description 1
- 238000004519 manufacturing process Methods 0.000 description 1
- 239000000203 mixture Substances 0.000 description 1
- 150000002989 phenols Chemical class 0.000 description 1
- 238000004064 recycling Methods 0.000 description 1
- 239000011265 semifinished product Substances 0.000 description 1
- 229910052708 sodium Inorganic materials 0.000 description 1
- 239000011734 sodium Substances 0.000 description 1
- 229910000029 sodium carbonate Inorganic materials 0.000 description 1
- 229910052979 sodium sulfide Inorganic materials 0.000 description 1
- 239000007787 solid Substances 0.000 description 1
- 241000894007 species Species 0.000 description 1
- 239000000725 suspension Substances 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
- 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
- D21C9/1063—Bleaching ; Apparatus therefor with compounds not otherwise provided for, e.g. activated gases
-
- 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
Landscapes
- Life Sciences & Earth Sciences (AREA)
- Engineering & Computer Science (AREA)
- Wood Science & Technology (AREA)
- Paper (AREA)
- Polysaccharides And Polysaccharide Derivatives (AREA)
Description
Foreliggende oppfinnelse vedrører en fremgangsmåte ved bleking av kjemisk fremstilt cellulose. The present invention relates to a method for bleaching chemically produced cellulose.
Med kjemisk fremstilt cellulose menes en cellulose som er fremstilt ut fra oppfliset trevirke gjennom koking med alkali eller syre, som regel i NaOH, Na2S og Na2C03 på den ene side eller kalsium- eller magnesium eller natrium- eller ammonium-bisulfitløsning på den annen side. Herunder opp-løses trevirkets ligniner og karbohydrater hvilke skilles fra cellulosen ved vasking. Avlutene oppkonsentreres til 50 til 60 % faststoffinnhold og brennes. Gjennom forbren-ningen kan en.del av prosessen energibehov dekkes. By chemically produced cellulose is meant a cellulose produced from chipped wood by boiling with alkali or acid, usually in NaOH, Na2S and Na2C03 on the one hand or calcium or magnesium or sodium or ammonium bisulphite solution on the other. Here, the wood's lignins and carbohydrates are dissolved, which are separated from the cellulose by washing. The liquors are concentrated to 50 to 60% solids content and burned. Part of the process's energy needs can be met through combustion.
Lignininnholdet til cellulosen som i koking- i stor grad blir befridd for lignin må likevel for fremstilling av høyverdig, trefritt papir senkes ytterligere. Dette skjer gjennom bleking hvorunder resten av ligninet overføres i vann- og/ eller alkaliløslige forbindelser og stoffet får en lysere farge. The lignin content of the cellulose, which is largely freed of lignin during cooking, must nevertheless be further lowered for the production of high-quality, wood-free paper. This takes place through bleaching, during which the rest of the lignin is transferred into water- and/or alkali-soluble compounds and the fabric acquires a lighter colour.
Hittil var det vanlig å behandle cellulosen i et første bleketrinn med en konsistens på ca. 3 % med en vandig klor-løsning. Kloreringen utføres i en reaktor hvori suspensjonen forblir ca. 30 til 60 minutter. Derved reagerer kloret med resten av ligninet, som derpå ekstraheres med en NaOH. Den nesten ligninfri relativt mørke fibermassen blekes med hypo-klorit, klordioksyd eller peroksyd ved ca. 10 % stoffden-sitet, høyere temperaturer og oppholdstider på flere timer pr. bleketrinn og delvis mellomkoblet alkali-ekstraksjoner til et salgbart halvfabrikata. En ulempe ved denne kjente fremgangsmåte er at man får klorholdig avløpsvann som er belastet med organiske substanser med høyt BSB (biologisk oksygenbehov) samt meget tungt biologisk nedbrytbare stoffer så som klorerte fenoler. På grunn av den høye korrosjons-evnen kan slike avluter ikke inndampes under økonomisk for-svarlige betingelser og forbrennes. Until now, it was common to process the cellulose in a first bleaching step with a consistency of approx. 3% with an aqueous chlorine solution. The chlorination is carried out in a reactor in which the suspension remains approx. 30 to 60 minutes. The chlorine thereby reacts with the rest of the lignin, which is then extracted with NaOH. The almost lignin-free, relatively dark fiber mass is bleached with hypochlorite, chlorine dioxide or peroxide at approx. 10% material density, higher temperatures and residence times of several hours per bleaching step and partly intermediate alkali extractions to a salable semi-finished product. A disadvantage of this known method is that you get chlorine-containing waste water which is loaded with organic substances with a high BOD (biological oxygen demand) as well as very difficult biodegradable substances such as chlorinated phenols. Due to the high corrosion potential, such effluents cannot be evaporated under economically responsible conditions and incinerated.
Det er også mulig å anvende peroksyd eller oksygen i stedet for klor. Anvendelsen må imidlertid finne sted i nærvær av alkali, hvor igjennom det i de følgende bleketrinn eller ved kjemikalie-gjenvinningen oppstår vanskeligheter dersom det dreier seg om sulfitcellulose som ble fremstilt med kalsium eller magnesium som base. Dessuten kan restdelignifiser-ingen av teknologiske grunner ikke gjennomføres så langt det ville være ønskelig. Det er allerede overveiet å anvende ozon som blekemiddel fordi man kunne vente en reduksjon av miljøbelastningen gjennom avvannet. Ozonblekingen kunne imidlertid ikke slå igjennom fordi det spesielt ved sulfatcellulose.r ikke lyktes å senke ozonforbruket til en økonomisk forsvarlig målestokk og fordi det videre ikke lyktes å bleke de to. vanlige arter av kjemisk fremstilt cellulose, nemlig sulfit- og sulfatcellulose med like godt resultat. It is also possible to use peroxide or oxygen instead of chlorine. The application must, however, take place in the presence of alkali, which causes difficulties in the following bleaching steps or during chemical recycling if it is a question of sulphite cellulose that was produced with calcium or magnesium as a base. Furthermore, for technological reasons, residual delignification cannot be carried out as far as would be desirable. It has already been considered to use ozone as a bleaching agent because one could expect a reduction of the environmental burden through the waste water. Ozone bleaching, however, could not be successful because it was not possible to reduce the ozone consumption to an economically justifiable scale, especially in the case of sulphate cellulose, and because it was also not possible to bleach the two. common species of chemically produced cellulose, namely sulphite and sulphate cellulose with equally good results.
Oppgaven for foreliggende oppfinnelse var nå å tilveiebringe en fremgangsmåte av den innledningsvis nevnte art slik at en. forbedring av blekeprosessen oppnås med hensyn til miljø-belastningen. Derunder har det vist seg at i tillegg til det tilstrebede, resultat reduseres også arbeidet varighet og det operative oppbud ved fremgangsmåten ifølge oppfinnelsen betydelig. The task for the present invention was now to provide a method of the nature mentioned at the outset so that a. improvement of the bleaching process is achieved with regard to the environmental impact. Below, it has been shown that in addition to the desired result, the duration of the work and the operational costs of the method according to the invention are also significantly reduced.
Den nevnte oppgave løser fremgangsmåten ifølge oppfinnelsen på overraskende enkel og økonomisk måte ved at cellulosen mens den underkastes en defibreringsoperasjon eller deretter behandles med nitrogenoksyder eller også saltpetersyre og ozon. På denne måte er det mulig å delignifisere begge typer av celluloser - sulfit- og sulfatcellulose. Anvendelsen av middelet nitrogenoksyd eller saltpetersyre og ozon lar seg tilpasse de foreliggende omstendigheter. Således kan f.eks. sulfatcellulosen behandles i et første trinn med nitrogenoksyd eller saltpetersyre og i et andre trinn med ozon, hvorunder man ved optimal dosering av middelet og hensikts-messig tilførsel kan arbeide meget økonomisk. Det er også mulig å utføre en alkali-ekstraksjon av cellulosen mellom de to behandlingstrinn, slik at ozonet bare må bleke lignin-rester som blir tilbake etter dette. Ligninet som er an-grepet i ozonbehandlingstrinnet er vannløslig. The above-mentioned task is solved by the method according to the invention in a surprisingly simple and economical way in that the cellulose is subjected to a defibration operation or is then treated with nitrogen oxides or also nitric acid and ozone. In this way, it is possible to delignify both types of cellulose - sulphite and sulphate cellulose. The use of the agent nitric oxide or nitric acid and ozone can be adapted to the present circumstances. Thus, e.g. the sulfated cellulose is treated in a first step with nitric oxide or nitric acid and in a second step with ozone, during which one can work very economically with optimal dosing of the agent and appropriate supply. It is also possible to carry out an alkali extraction of the cellulose between the two treatment steps, so that the ozone only has to bleach lignin residues that remain after this. The lignin that is attacked in the ozone treatment step is water-soluble.
Dersom foreliggende cellulose er. egnet for dette kan be-handlingen foretas med nitrogenoksyd og ozon samtidig. If the present cellulose is. suitable for this, the treatment can be carried out with nitrogen oxide and ozone at the same time.
Også andre varianter av fremgangsmåteutførelsen er tenkelige, f.eks. på den måte at det etter en første nitrogenoksyd-eller saltpetersyrebehandling følger en andre kombinert nitrogenoksyd-ozonbehandling og - eventuelt etter en alkali-ekstraksjon - behandler man videre med ozon. Other variants of the method implementation are also conceivable, e.g. in such a way that after a first nitric oxide or nitric acid treatment, a second combined nitric oxide-ozone treatment follows and - possibly after an alkali extraction - further treatment with ozone.
Anvendelsen av nitrogenoksydet som for eksempel reduseres meget ved sulfitcelluloser eller helt unngås, belaster ikke økonomien ved fremgangsmåten i nevneverdig grad fordi nitrogenoksyder kan kjøpes eller fremstilles billig. The use of nitrogen oxide, which is, for example, greatly reduced with sulphite celluloses or completely avoided, does not burden the economics of the process to a significant extent because nitrogen oxides can be bought or produced cheaply.
Mens det dannede avløpsvann hittil ved den konvensjonelle bleking tilføres forstrømmen uten klaring, kunne ved an-vendelse av fremgangsmåten ifølge oppfinnelsen avlutene tilføres i det generelle avlut-kretsløp og til slutt forbrennes. While the waste water produced until now in the case of conventional bleaching is supplied to the pre-flow without clarification, by using the method according to the invention the effluents could be fed into the general effluent circuit and finally incinerated.
Innretningene som anvendes for utførelse av fremgangsmåten ifølge oppfinnelsen er enkle. For blanding av nitrogenoksyd og ozon med cellulose under samtidig defibrering kan det anvendes en egnet rafinør som er utstyrt med tilførsels-anordninger for den aktuelle gass eller gassblanding. Når flere tilblandinger er nødvendige eller tilrådelige, kan en vifte anvendes som blandingsaggregat så snart fibrene er tilstrekkelig oppsluttet, hvilken sørger for videre trans-port av stoffet idet gasstilførselen skjer i vifteløpsområdet. The devices used for carrying out the method according to the invention are simple. For mixing nitrogen oxide and ozone with cellulose during simultaneous defibration, a suitable refiner can be used which is equipped with supply devices for the relevant gas or gas mixture. When more admixtures are necessary or advisable, a fan can be used as a mixing unit as soon as the fibers are sufficiently mixed up, which ensures further transport of the material as the gas supply takes place in the fan run area.
Fremgangsmåten anskueliggjøres gjennom det følgende eksempel: I et første trinn bringes 2 % nitrogenoksyd ved romtemperatur eller også ved høyere temperatur til å innvirke på en grantre-cellulose med kappatall på ca. 30, mens dette, går gjennom The procedure is illustrated through the following example: In a first step, 2% nitrogen oxide at room temperature or also at a higher temperature is brought to act on a spruce wood cellulose with a kappa number of approx. 30, while this, goes through
en rafinør. Cellulosens konsistens kan i dette behandl.ings-trinn ligge mellom 10 og 50 %, fortrinnsvis ved 35 %. Herigjennom nedbrytes det restlignin som fortsatt er til stede etter kokingen så langt at det ved senere vask delvis a refiner. The consistency of the cellulose in this treatment step can be between 10 and 50%, preferably at 35%. As a result, the residual lignin that is still present after boiling is broken down to such an extent that it partially breaks down during later washing
med vann, men helst med en vandig alkaliløsning kan fjernes.Cellulosens kåppatall reduseres derved med ca. 15 enheter. På den etterfølgende behandling av den meget konsentrerte cellulose med ozon reagerer det fortsatt tilstedeværende restlignin i likhet med sulfitligninet slik at hvithets-graden til cellulosen bare øker med 20-25 hvithetsgrad-punkter ved tilførsel av bare 1 % ozon ved romtemperatur. Etter en vask av cellulosen uten ytterligere kjemikalier ligger cellulosens kåppatall under 5. Sluttblekingen til høyeste hvithetsgrad kan om nødvendig utføres med små mengder konvensjonelle blekemidler. can be removed with water, but preferably with an aqueous alkali solution. The cellulose's coat number is thereby reduced by approx. 15 units. On the subsequent treatment of the highly concentrated cellulose with ozone, the still present residual lignin reacts in the same way as the sulphite lignin so that the whiteness of the cellulose only increases by 20-25 whiteness points when only 1% ozone is added at room temperature. After washing the cellulose without additional chemicals, the cellulose's coat number is below 5. The final bleaching to the highest degree of whiteness can be carried out if necessary with small amounts of conventional bleaching agents.
Claims (4)
Applications Claiming Priority (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| DE3118384A DE3118384C1 (en) | 1981-05-09 | 1981-05-09 | Process for bleaching chemically produced pulp with ozone |
Publications (1)
| Publication Number | Publication Date |
|---|---|
| NO821525L true NO821525L (en) | 1982-11-10 |
Family
ID=6131844
Family Applications (1)
| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| NO821525A NO821525L (en) | 1981-05-09 | 1982-05-07 | PROCEDURE FOR CHEMICAL PREPARATION OF CELLULOSE. |
Country Status (9)
| Country | Link |
|---|---|
| JP (1) | JPS57191388A (en) |
| AT (1) | ATA167682A (en) |
| BR (1) | BR8202532A (en) |
| DE (1) | DE3118384C1 (en) |
| FI (1) | FI821265A0 (en) |
| FR (1) | FR2505377A1 (en) |
| NO (1) | NO821525L (en) |
| SE (1) | SE8202603L (en) |
| ZA (1) | ZA823048B (en) |
Families Citing this family (3)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| AT404740B (en) * | 1989-10-30 | 1999-02-25 | Chemiefaser Lenzing Ag | Process for the chlorine-free bleaching of pulps |
| DE4107356C1 (en) * | 1991-03-08 | 1992-11-05 | Acetocell Gmbh & Co Kg, 7162 Gschwend, De | |
| US5364503A (en) * | 1992-02-20 | 1994-11-15 | Macmillan Bloedel Limited | Nitric oxide treatment for ozone bleaching |
Family Cites Families (5)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| FR432552A (en) * | 1911-07-25 | 1911-12-09 | Claude Achilles Meygret | Improvements in the bleaching of vegetable fibers, vegetable pulps and their equivalents |
| FR2158873A5 (en) * | 1972-10-09 | 1973-06-15 | Bourit Jean Pierre | Bleaching of wood cellulose - using nitrogen oxides |
| GB1505070A (en) * | 1974-06-11 | 1978-03-22 | Canadian Ind | Process for bleaching of lignocellulosic material |
| CA1070909A (en) * | 1976-05-04 | 1980-02-05 | Canadian Industries Limited | Nitrogen dioxide-oxygen delignification |
| GB1590704A (en) * | 1976-11-23 | 1981-06-10 | Defibrator Ab | Method end device for the continuous production of pulp from fibrous lignocellulosic materials |
-
1981
- 1981-05-09 DE DE3118384A patent/DE3118384C1/en not_active Expired
-
1982
- 1982-03-31 FR FR8205593A patent/FR2505377A1/en not_active Withdrawn
- 1982-04-08 FI FI821265A patent/FI821265A0/en not_active Application Discontinuation
- 1982-04-26 SE SE8202603A patent/SE8202603L/en not_active Application Discontinuation
- 1982-04-29 AT AT0167682A patent/ATA167682A/en not_active IP Right Cessation
- 1982-05-03 BR BR8202532A patent/BR8202532A/en unknown
- 1982-05-04 ZA ZA823048A patent/ZA823048B/en unknown
- 1982-05-04 JP JP57073504A patent/JPS57191388A/en active Pending
- 1982-05-07 NO NO821525A patent/NO821525L/en unknown
Also Published As
| Publication number | Publication date |
|---|---|
| SE8202603L (en) | 1982-11-10 |
| ATA167682A (en) | 1985-04-15 |
| BR8202532A (en) | 1983-04-19 |
| ZA823048B (en) | 1983-03-30 |
| FI821265A0 (en) | 1982-04-08 |
| JPS57191388A (en) | 1982-11-25 |
| DE3118384C1 (en) | 1982-11-11 |
| FR2505377A1 (en) | 1982-11-12 |
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