EP0148712A1 - Process for bleaching paper pulps with hydrogen peroxide - Google Patents
Process for bleaching paper pulps with hydrogen peroxide Download PDFInfo
- Publication number
- EP0148712A1 EP0148712A1 EP84420215A EP84420215A EP0148712A1 EP 0148712 A1 EP0148712 A1 EP 0148712A1 EP 84420215 A EP84420215 A EP 84420215A EP 84420215 A EP84420215 A EP 84420215A EP 0148712 A1 EP0148712 A1 EP 0148712A1
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- European Patent Office
- Prior art keywords
- hydrogen peroxide
- weight
- concentration
- alkaline
- bleaching
- Prior art date
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Classifications
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- 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
Definitions
- the present invention relates to a process for bleaching chemical pulp with hydrogen peroxide.
- the bleaching of chemical paper pulp that is to say unbleached cellulose pulp obtained by cooking lignocellulosic materials according to so-called sulphite, sulphate or Kraft, sodium hydroxide or carbonate processes, is generally practiced in industry using chlorine or chlorine derivatives having, like chlorine, an oxidizing character, such as chlorine dioxide C10 2 or sodium hypochlorite NaOC1.
- None of these oxidizing agents is, however, capable of ensuring a single, satisfactory whitening in a single operation. It is necessary to operate in several distinct stages and in intermediate operations such as in particular so-called alkaline bath extraction operations.
- the effluents resulting from such operating sequences are very strongly colored, polluting and corrosive. They can even cause risks of explosion during the reagent regeneration cycle. They contain in particular large quantities of chlorinated organic products and chloride ions. As a result, they cannot be rejected or recycled without complex and costly treatments.
- Hydrogen peroxide can be used at atmospheric pressure in conventional bleaching equipment. Its direct use on unbleached pasta with a kappa index of around 30, however, did not make it possible to obtain processed pasta with a kappa index of less than approximately 20-25.
- An additional step of pretreatment of the pasta in an acid medium allows, as described in Japanese patent application n ° 76/102103 and French patent application n ° 77. 24131 to improve this result but, like the set of known bleaching processes based on alternating steps in acid bath and in alkaline bath, does not avoid the problems raised by the rejection or recycling of liquors after use, nor reach low kappa degrees for processed pasta.
- the method according to the invention makes it possible to obtain bleached cellulosic pulp pulp with a kappa index of less than 10 while delivering directly recyclable effluents in the bleaching operation.
- It consists of treating unbleached cellulose pulp with hydrogen peroxide, in a single step, at a temperature between 70 ° C and 100 ° C, using a bleaching bath of pH maintained between 11 and 11.5 and comprising, in addition to hydrogen peroxide, at least one alkaline agent chosen from sodium hydroxide and sodium carbonate, at least one alkali metal silicate at a concentration expressed as silica Si0 2 at least equal at 0.3% by weight, at least one magnesium salt and at least one calcium salt, in an amount such that the concentration by weight of each of the alkaline earth elements is between 0.05% and 1%, kept dissolved using at least one complexing agent for alkaline earth ions, the overall concentration in compexing does not exceed 10% by weight.
- a bleaching bath of pH maintained between 11 and 11.5 comprising, in addition to hydrogen peroxide, at least one alkaline agent chosen from sodium hydroxide and sodium carbonate, at least one alkali metal silicate at a concentration expressed as silica Si0 2 at least equal at 0.
- the concentration of hydrogen peroxide in the bleaching bath is that commonly adopted in this industrial field. It generally does not exceed 1% by weight and is most often between 0.02 and 0.5%.
- the concentration by weight of alkali metal silicate, expressed as Si0 2 is chosen, for reasons of economy, less than 20% and is most often less than 5%.
- the most suitable calcium salts and magnesium salts are those whose anion exhibits the best inertia with respect to hydrogen peroxide under the conditions for carrying out the process of the invention, such as, for example, chlorides .
- the complexing agent (s) for the magnesium and calcium ions are for example chosen from polyphosphates and pyrophosphates of alkali metal, nitrogen acids, such as ethylenediaminetetracetic acid, diethylenetriaminepentacetic acid and nitri-lotriacetic acid, or their salts, monomeric or polymeric phosphoric acids, polyelectrolytes such as poly- ⁇ hydroxyacrylic acid and the corresponding lactone.
- the bleaching obtained remains excellent but requires to be achieved quickly prohibitive residence times.
- the process of the invention is carried out at a temperature above 100 ° C., the decomposition of hydrogen peroxide quickly becomes annoying.
- the preferred temperature range is 85 ° C to 95 ° C.
- the mode of constitution of the bleaching bath can be arbitrary, it is preferred to carry out the solubilization in aqueous medium of the calcium and magnesium salts in the presence of the agent or agents complexing the alkaline earth ions, to then introduce into the solution thus obtained the alkali metal silicate in the form of a concentrated aqueous solution, then the hydrogen peroxide solution before bringing the pH of the mixture to a value between 11 and 11.5 using hydroxide or sodium carbonate,
- the contact of the dough to be bleached with the bath formed for this purpose is carried out either discontinuously or continuously, by passage of the bleaching solution through a solid phase consisting of cellulosic material, or by intimate mixing of this solution with this solid phase.
- the weight ratio of bleaching solution / solid material can be between 10 and 100 and preferably between 15 and 50. In the second case this ratio can be between 4 and 100 and preferably between 8 and 20.
- the pulp after treatment has a kappa index which is no more than 8, the quantity of hydrogen peroxide consumed to achieve this result representing only 4% by weight of the pulp engaged.
- Example 2 By operating as in Example 1 and retaining as a bleaching solution the solution which served to treat the charge of unbleached pulp of Example 1, a second charge of unbleached pulp is treated then a third. At the end of this third operation, it is found that the bleaching bath has retained all its effectiveness since the treated dough has a kappa index of 8 while the consumption of hydrogen peroxide is 4.1% by weight relative to by the weight of committed dough.
- Example 1 10 g of unbleached dough of the same origin and of the same kappa index as in Example 1 are mixed with 100 g of solution of the same weight composition as in Example 1. The mixture is maintained at 90 ° C for 10 hours with introduction , after 5 hours, 0.34 g of hydrogen peroxide.
- the pulp, after treatment, has a kappa index equal to 8, the consumption of hydrogen peroxide to achieve this result being only 4.3% by weight relative to the pulp engaged.
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- Life Sciences & Earth Sciences (AREA)
- Engineering & Computer Science (AREA)
- Wood Science & Technology (AREA)
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Abstract
Description
La présente invention concerne un procédé de blanchiment de pâtes papetières chimiques par le peroxyde d'hydrogène.The present invention relates to a process for bleaching chemical pulp with hydrogen peroxide.
Le blanchiment des pâtes papetières chimiques, c'est-à-dire des pâtes de cellulose écrues obtenues par cuisson de matières lignocellulosiques selon les procédés dits au sulfite, au sulfate ou Kraft, à la soude ou au carbonate, est généralement pratiqué dans l'industrie à l'aide de chlore ou de dérivés chlorés ayant comme le chlore un caractère oxydant, tels que le bioxyde de chlore C102 ou l'hypochlorite de sodium NaOC1.The bleaching of chemical paper pulp, that is to say unbleached cellulose pulp obtained by cooking lignocellulosic materials according to so-called sulphite, sulphate or Kraft, sodium hydroxide or carbonate processes, is generally practiced in industry using chlorine or chlorine derivatives having, like chlorine, an oxidizing character, such as chlorine dioxide C10 2 or sodium hypochlorite NaOC1.
Aucun de ces agents oxydants n'est toutefois capable d'assurer seul un,blanchiment satisfaisant en une seule opération. Il est nécessaire d'opérer en plusieurs étapes distinctes et à des opérations intermédiaires telles qu'en particulier des opérations dites d'extraction en bain alcalin. Les effluents résultant de telles séquences opératoires sont très fortement colorés, polluants et corrosifs. Ils peuvent même entraîner des risques d'explosion au cours du cycle de régénération des réactifs. Ils renferment en particulier des quantités importantes de produits organiques chlorés et des ions chlorures. De ce fait ils ne peuvent être rejetés ni recyclés sans que soit procédé à des traitements complexes et coûteux.None of these oxidizing agents is, however, capable of ensuring a single, satisfactory whitening in a single operation. It is necessary to operate in several distinct stages and in intermediate operations such as in particular so-called alkaline bath extraction operations. The effluents resulting from such operating sequences are very strongly colored, polluting and corrosive. They can even cause risks of explosion during the reagent regeneration cycle. They contain in particular large quantities of chlorinated organic products and chloride ions. As a result, they cannot be rejected or recycled without complex and costly treatments.
L'emploi d'agents oxydants non chlorés, notamment celui de l'oxygène ou du peroxyde d'hydrogène, a été envisagé pour pallier les inconvénients cités. Celui de l'oxygène, qui contraint à un fonctionnement sous pression et par là onéreux, n'a connu qu'un développement limité.The use of non-chlorinated oxidizing agents, in particular that of oxygen or hydrogen peroxide, has been envisaged in order to overcome the cited drawbacks. That of oxygen, which forces it to operate under pressure and is therefore expensive, has experienced only limited development.
Le peroxyde d'hydrogène peut être mis en oeuvre à pression atmosphérique dans les appareillages conventionnels de blanchiment. Son emploi direct sur des pâtes écrues d'indice kappa de l'ordre de 30 n'a toutefois pas permis d'obtenir des pâtes traitées d'indice kappa inférieur à 20-25 environ. Une étape supplémentaire de prétraitement des pâtes en milieu acide permet, comme le décrit la demande de brevet japonais n° 76/102103 et la demande de brevet français n° 77. 24131 d' améliorer ce résultat mais, à l'image de l'ensemble des procédés connus de blanchiment reposant sur des étapes alternées en bain acide et en bain alcalin, ne permet pas d'éviter les problèmes soulevés par le rejet ou le recyclage des liqueurs après usage, ni d'atteindre des degrés kappa faibles pour les pâtes traitées.Hydrogen peroxide can be used at atmospheric pressure in conventional bleaching equipment. Its direct use on unbleached pasta with a kappa index of around 30, however, did not make it possible to obtain processed pasta with a kappa index of less than approximately 20-25. An additional step of pretreatment of the pasta in an acid medium allows, as described in Japanese patent application n ° 76/102103 and French patent application n ° 77. 24131 to improve this result but, like the set of known bleaching processes based on alternating steps in acid bath and in alkaline bath, does not avoid the problems raised by the rejection or recycling of liquors after use, nor reach low kappa degrees for processed pasta.
Le procédé selon l'invention permet d'assurer l'obtention de pates papetières cellulosiques blanchies d'indice kappa inférieur à 10 tout en délivrant des effluents directement recyclables dans l'opération dé blanchiment.The method according to the invention makes it possible to obtain bleached cellulosic pulp pulp with a kappa index of less than 10 while delivering directly recyclable effluents in the bleaching operation.
Il consiste à traiter des pâtes papetières cellulosiques écrues par le peroxyde d'hydrogène, en une seule étape, à une température comprise entre 70°C et 100°C, à l'aide d'un bain de blanchiment de pH maintenu entre 11 et 11,5 et comprenant,en plus du peroxyde d'hydrogène, au moins un agent alcalin choisi parmi l'hydroxyde de sodium et le carbonate de sodium, au moins un silicate de métal alcalin à une concentration exprimée en silice Si02 au moins égale à 0,3 % en poids, au moins un sel de magnésium et au moins un sel de calcium, en quantité telle que la concentration en poids de chacun des éléments alcalino-terreux soit comprise entre 0,05 % et 1 %, maintenus dissous à l'aide d'au moins un agent complexant des ions alcalino-terreux, la concentration globale en compiexant n'excédant pas 10 % en poids.It consists of treating unbleached cellulose pulp with hydrogen peroxide, in a single step, at a temperature between 70 ° C and 100 ° C, using a bleaching bath of pH maintained between 11 and 11.5 and comprising, in addition to hydrogen peroxide, at least one alkaline agent chosen from sodium hydroxide and sodium carbonate, at least one alkali metal silicate at a concentration expressed as silica Si0 2 at least equal at 0.3% by weight, at least one magnesium salt and at least one calcium salt, in an amount such that the concentration by weight of each of the alkaline earth elements is between 0.05% and 1%, kept dissolved using at least one complexing agent for alkaline earth ions, the overall concentration in compexing does not exceed 10% by weight.
La concentration en peroxyde d'hydrogène dans le bain de blanchiment est celle communément adoptée dans ce domaine industriel. Elle n'excède généralement pas 1 % en poids et est le plus souvent comprise entre 0,02 et 0,5 %.The concentration of hydrogen peroxide in the bleaching bath is that commonly adopted in this industrial field. It generally does not exceed 1% by weight and is most often between 0.02 and 0.5%.
La concentration pondérale de silicate de métal alcalin, exprimée en Si02, est choisie, pour des raisons d'économie, inférieure à 20 % et est le plus souvent inférieure à 5 %.The concentration by weight of alkali metal silicate, expressed as Si0 2 , is chosen, for reasons of economy, less than 20% and is most often less than 5%.
Les sels de calcium et les sels de magnésium convenant le mieux sont ceux dont l'anion présente la meilleure inertie vis-à-vis du peroxyde d'hydrogène dans les conditions d'exécution du procédé de l'invention, comme par exemple les chlorures.The most suitable calcium salts and magnesium salts are those whose anion exhibits the best inertia with respect to hydrogen peroxide under the conditions for carrying out the process of the invention, such as, for example, chlorides .
Le ou les complexants des ions magnésium et calcium sont par exemple choisis parmi les polyphosphates et les pyrophosphates de métal alcalin, les acides azotés, tels que l'acide éthylènediamine- tetracétique, l'acide diéthylènetriaminepentacétique et l'acide nitri- lotriacétique, ou leurs sels, les acides phosphoriques monomères ou polymères, les polyélectrolytes tels que l'acide poly-α hydroxyacrylique et la lactone correspondante.The complexing agent (s) for the magnesium and calcium ions are for example chosen from polyphosphates and pyrophosphates of alkali metal, nitrogen acids, such as ethylenediaminetetracetic acid, diethylenetriaminepentacetic acid and nitri-lotriacetic acid, or their salts, monomeric or polymeric phosphoric acids, polyelectrolytes such as poly-α hydroxyacrylic acid and the corresponding lactone.
L'hydroxyde de sodium et le carbonate de sodium ont été préférés à d'autres agents alcalins pour des raisons économiques.Sodium hydroxide and sodium carbonate have been preferred over other alkaline agents for economic reasons.
Lorsque le procédé selon l'invention est réalisé à une température inférieure à 70°C, le blanchiment obtenu reste excellent mais demande pour être atteint des temps de séjour rapidement prohibitifs. Lorsque le procédé de l'invention est réalisé à une température supérieure à 100°C la décomposition du peroxyde d'hydrogène devient vite génante. La plage de température préférée est de 85°C à 95°C.When the process according to the invention is carried out at a temperature below 70 ° C., the bleaching obtained remains excellent but requires to be achieved quickly prohibitive residence times. When the process of the invention is carried out at a temperature above 100 ° C., the decomposition of hydrogen peroxide quickly becomes annoying. The preferred temperature range is 85 ° C to 95 ° C.
Bien que le mode de constitution du bain de blanchiment puisse être quelconque, il est préféré de procéder à la solubilisation en milieu aqueux des sels de calcium et de magnésium en présence du ou des agents complexant les ions alcalino-terreux, d'introduire ensuite dans la solution ainsi obtenue le silicate de métal alcalin sous forme de solution aqueuse concentrée, puis la solution de peroxyde d'hydrogène avant d'amener le pH du mélange à une valeur comprise entre 11 et 11,5 à l'aide d'hydroxyde ou de carbonate de sodium,Although the mode of constitution of the bleaching bath can be arbitrary, it is preferred to carry out the solubilization in aqueous medium of the calcium and magnesium salts in the presence of the agent or agents complexing the alkaline earth ions, to then introduce into the solution thus obtained the alkali metal silicate in the form of a concentrated aqueous solution, then the hydrogen peroxide solution before bringing the pH of the mixture to a value between 11 and 11.5 using hydroxide or sodium carbonate,
Le contact de la pâte à blanchir avec le bain constitué à cet effet, dont la durée peut varier en particulier en fonction de la température mais n'excède généralement pas une dizaine d'heures, est réalisé soit en discontinu, soit en continu, par passage de la solution de blanchiment à travers une phase solide constituée de la matière cellulosique, soit par mélange intime de cette solution avec cette phase solide.The contact of the dough to be bleached with the bath formed for this purpose, the duration of which may vary in particular depending on the temperature but generally does not exceed ten hours, is carried out either discontinuously or continuously, by passage of the bleaching solution through a solid phase consisting of cellulosic material, or by intimate mixing of this solution with this solid phase.
Dans le premier cas, c'est-à-dire dans une technique de percolation, le rapport pondéral solution de blanchiment/matière solide peut être compris entre 10 et 100 et de préférence entre 15 et 50. Dans le second cas ce rapport peut être compris entre 4 et 100 et de préférence entre 8 et 20.In the first case, that is to say in a percolation technique, the weight ratio of bleaching solution / solid material can be between 10 and 100 and preferably between 15 and 50. In the second case this ratio can be between 4 and 100 and preferably between 8 and 20.
Les exemples suivants, donnés à titre non limitatif, illustrent le procédé de l'invention :The following examples, given without limitation, illustrate the process of the invention:
20 g de pâte écrue issue d'une cuisson Kraft de résineux et ayant un indice kappa égal à 30 sont traités par percolation, à 90°C, durant 8 heures, à l'aide de 500 g de solution de blanchiment de pH maintenu constant à une valeur comprise entre 11 et 11,5 par adjonction d'hydroxyde de sodium, circulant en boucle fermée à raison de 300 ml/h, de teneur en peroxyde d'hydrogène maintenue constante par adjonction de ce réactif, et contenant, en poids :
La pâte après traitement a un indice kappa qui n'est plus que de 8, la quantité de peroxyde d'hydrogène consommée pour atteindre ce résultat ne représentant que 4 % en poids de la pâte engagée.The pulp after treatment has a kappa index which is no more than 8, the quantity of hydrogen peroxide consumed to achieve this result representing only 4% by weight of the pulp engaged.
En opérant comme dans l'exemple 1 et en conservant comme solution de blanchiment la solution ayant servi à traiter la charge de pâte écrue de l'exemple 1, on traite une deuxième charge de pâte écrue puis une troisième. A l'issue de cette troisième opération il est constaté que le bain de blanchiment a conservé toute son efficacité puisque la pâte traitée a un indice kappa de 8 tandis que la consommation de peroxyde d'hydrogène est de 4,1 % en poids par rapport au poids de pâte engagée.By operating as in Example 1 and retaining as a bleaching solution the solution which served to treat the charge of unbleached pulp of Example 1, a second charge of unbleached pulp is treated then a third. At the end of this third operation, it is found that the bleaching bath has retained all its effectiveness since the treated dough has a kappa index of 8 while the consumption of hydrogen peroxide is 4.1% by weight relative to by the weight of committed dough.
10 g de pâte écrue de même origine et de même indice kappa que dans l'exemple 1 sont mélangés à 100 g de solution de même composition pondérale que dans l'exemple 1. Le mélange est maintenu à 90°C pendant 10 heures avec introduction, après 5 heures, de 0,34 g de peroxyde d'hydro gène.10 g of unbleached dough of the same origin and of the same kappa index as in Example 1 are mixed with 100 g of solution of the same weight composition as in Example 1. The mixture is maintained at 90 ° C for 10 hours with introduction , after 5 hours, 0.34 g of hydrogen peroxide.
La pâte, après traitement, a un indice kappa égal à 8, la consommation de peroxyde d'hydrogène pour atteindre ce résultat n'étant que de 4,3 % en poids par rapport à la pâte engagée.The pulp, after treatment, has a kappa index equal to 8, the consumption of hydrogen peroxide to achieve this result being only 4.3% by weight relative to the pulp engaged.
Un résultat analogue est obtenu lorsque l'on opère à la même température que ci-dessus mais en continu avec introduction de pâte à blanchir et sortie équivalente de pâte blanchie en recyclant la solution de blanchiment, séparée de la pâte extraite et remise au titre en peroxyde d'hydrogène et autres ingrédients constitutifs du bain de blanchiment tel que défini pour le procédé selon l'invention, de telle façon que dans la zone de traitement s'établisse un régime stationnaire et que le contact soit assuré durant une période de 8 heures entre la pâte et la solution de blanchiment.A similar result is obtained when operating at the same temperature as above but continuously with the introduction of bleaching pulp and equivalent output of bleached pulp by recycling the bleaching solution, separated from the pulp extracted and returned to the title. hydrogen peroxide and other constituent ingredients of the bleaching bath as defined for the process according to the invention, so that in the treatment zone a steady state is established and that contact is ensured during a period of 8 hours between the dough and the bleaching solution.
Claims (5)
Priority Applications (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| AT84420215T ATE29537T1 (en) | 1983-12-29 | 1984-12-21 | PROCESS FOR BLEACHING PAPER PULP USING HYDROGEN PEROXIDE. |
Applications Claiming Priority (2)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| FR8320990 | 1983-12-29 | ||
| FR8320990A FR2557605B1 (en) | 1983-12-29 | 1983-12-29 | PROCESS FOR BLEACHING PAPER PULP BY HYDROGEN PEROXIDE |
Publications (2)
| Publication Number | Publication Date |
|---|---|
| EP0148712A1 true EP0148712A1 (en) | 1985-07-17 |
| EP0148712B1 EP0148712B1 (en) | 1987-09-09 |
Family
ID=9295687
Family Applications (1)
| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| EP84420215A Expired EP0148712B1 (en) | 1983-12-29 | 1984-12-21 | Process for bleaching paper pulps with hydrogen peroxide |
Country Status (9)
| Country | Link |
|---|---|
| EP (1) | EP0148712B1 (en) |
| JP (1) | JPS60181391A (en) |
| AT (1) | ATE29537T1 (en) |
| AU (1) | AU567787B2 (en) |
| CA (1) | CA1262805A (en) |
| DE (2) | DE148712T1 (en) |
| ES (1) | ES8602173A1 (en) |
| FI (1) | FI76135C (en) |
| FR (1) | FR2557605B1 (en) |
Cited By (8)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| EP0226114A1 (en) * | 1985-12-16 | 1987-06-24 | SKW Trostberg Aktiengesellschaft | Process for bleaching and delignification of cellulosic products |
| EP0622491A2 (en) * | 1993-04-20 | 1994-11-02 | Eka Nobel Ab | Method for bleaching lignocellulose-containing pulp |
| EP0679760A1 (en) * | 1991-04-30 | 1995-11-02 | Eka Nobel Ab | Process for bleaching of lignocellulose-containing pulp |
| EP0866095A1 (en) * | 1997-03-13 | 1998-09-23 | 3V SIGMA S.p.A | Compositions for bleaching paper |
| GB2327894A (en) * | 1997-08-01 | 1999-02-10 | Nippon Paint Co Ltd | Method of multi-layer coating formation |
| WO1999060201A2 (en) * | 1998-05-15 | 1999-11-25 | National Silicates Partnership. | Peroxide, oxygen, and peroxide/oxygen brightening of chemical and mixed waste pulps |
| US6699358B1 (en) | 1998-05-15 | 2004-03-02 | National Silicates Partnership | Method for brightening chemical pulp with hydrogen peroxide using a magnesium compound in silicate solution |
| WO2012037024A2 (en) | 2010-09-16 | 2012-03-22 | Georgia-Pacific Consumer Products Lp | High brightness pulps from lignin rich waste papers |
Families Citing this family (2)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| JPH0642046B2 (en) * | 1987-01-29 | 1994-06-01 | 新王子製紙株式会社 | Support for photographic paper |
| US7001484B2 (en) | 2000-05-04 | 2006-02-21 | University Of New Brunswick | Peroxide bleaching of wood pulp using stabilizers and sodium hydrosulfide reducing agent |
Citations (5)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| US3003910A (en) * | 1958-05-29 | 1961-10-10 | Degussa | Peroxidic bleach containing silicic acid ester |
| FR2038056A1 (en) * | 1969-03-07 | 1971-01-08 | Air Liquide | Stable, clear bleaching bath for paper - pulp |
| FR2323807A1 (en) * | 1975-09-09 | 1977-04-08 | Sca Development Ab | Peroxide bleaching lignocellulose pulp produced in refiner - after treatment with soluble calcium salts esp. calcium chloride |
| JPS55158394A (en) * | 1979-05-29 | 1980-12-09 | Oji Paper Co | Peroxygen bleaching method of wood pulp |
| EP0034856A1 (en) * | 1980-02-21 | 1981-09-02 | INTEROX Société Anonyme | Process for inhibiting corrosion of apparatuses made of titanium |
Family Cites Families (3)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| US437813A (en) * | 1890-10-07 | Envelope-machine | ||
| US3472813A (en) * | 1967-01-18 | 1969-10-14 | Argus Chem | Resistance of acrylonitrile butadiene styrene polymers to discoloration |
| JPS583074B2 (en) * | 1975-11-17 | 1983-01-19 | 三菱瓦斯化学株式会社 | Palpuno Kasan Kabutsu Hiyou Hakuhou |
-
1983
- 1983-12-29 FR FR8320990A patent/FR2557605B1/en not_active Expired
-
1984
- 1984-12-21 AT AT84420215T patent/ATE29537T1/en not_active IP Right Cessation
- 1984-12-21 DE DE198484420215T patent/DE148712T1/en active Pending
- 1984-12-21 DE DE8484420215T patent/DE3466024D1/en not_active Expired
- 1984-12-21 EP EP84420215A patent/EP0148712B1/en not_active Expired
- 1984-12-27 FI FI845121A patent/FI76135C/en not_active IP Right Cessation
- 1984-12-27 JP JP59274194A patent/JPS60181391A/en active Granted
- 1984-12-28 AU AU37243/84A patent/AU567787B2/en not_active Ceased
- 1984-12-28 ES ES539151A patent/ES8602173A1/en not_active Expired
- 1984-12-28 CA CA000471164A patent/CA1262805A/en not_active Expired
Patent Citations (5)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| US3003910A (en) * | 1958-05-29 | 1961-10-10 | Degussa | Peroxidic bleach containing silicic acid ester |
| FR2038056A1 (en) * | 1969-03-07 | 1971-01-08 | Air Liquide | Stable, clear bleaching bath for paper - pulp |
| FR2323807A1 (en) * | 1975-09-09 | 1977-04-08 | Sca Development Ab | Peroxide bleaching lignocellulose pulp produced in refiner - after treatment with soluble calcium salts esp. calcium chloride |
| JPS55158394A (en) * | 1979-05-29 | 1980-12-09 | Oji Paper Co | Peroxygen bleaching method of wood pulp |
| EP0034856A1 (en) * | 1980-02-21 | 1981-09-02 | INTEROX Société Anonyme | Process for inhibiting corrosion of apparatuses made of titanium |
Non-Patent Citations (2)
| Title |
|---|
| ABSTRACT BULLETIN OF THE INSTITUTE OF PAPER CHEMISTRY, vol. 48, no. 7, janvier 1978, page 785, résumé 7253, Appleton, Wisc., US; B. LIPIC: "Influence of alkaline earth chlorides on groundwood bleaching", & ZELLSTOFF PAPIER 26, no. 7: 203-206, juillet 1977. * |
| ABSTRACT BULLETIN OF THE INSTITUTE OF PAPER CHEMISTRY, vol. 51, no. 11, mai 1981, page 1240, résumé 11637, Appleton, Wisc., US * |
Cited By (11)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| EP0226114A1 (en) * | 1985-12-16 | 1987-06-24 | SKW Trostberg Aktiengesellschaft | Process for bleaching and delignification of cellulosic products |
| US5034096A (en) * | 1985-12-16 | 1991-07-23 | Skw Trostberg Aktiengesellschaft | Process for bleaching and delignifying cellulose-containing products |
| EP0679760A1 (en) * | 1991-04-30 | 1995-11-02 | Eka Nobel Ab | Process for bleaching of lignocellulose-containing pulp |
| EP0622491A2 (en) * | 1993-04-20 | 1994-11-02 | Eka Nobel Ab | Method for bleaching lignocellulose-containing pulp |
| EP0622491A3 (en) * | 1993-04-20 | 1995-04-12 | Eka Nobel Ab | Method for bleaching lignocellulose-containing pulp. |
| EP0866095A1 (en) * | 1997-03-13 | 1998-09-23 | 3V SIGMA S.p.A | Compositions for bleaching paper |
| GB2327894A (en) * | 1997-08-01 | 1999-02-10 | Nippon Paint Co Ltd | Method of multi-layer coating formation |
| WO1999060201A2 (en) * | 1998-05-15 | 1999-11-25 | National Silicates Partnership. | Peroxide, oxygen, and peroxide/oxygen brightening of chemical and mixed waste pulps |
| WO1999060201A3 (en) * | 1998-05-15 | 2000-08-03 | Nat Silicates Ltd | Peroxide, oxygen, and peroxide/oxygen brightening of chemical and mixed waste pulps |
| US6699358B1 (en) | 1998-05-15 | 2004-03-02 | National Silicates Partnership | Method for brightening chemical pulp with hydrogen peroxide using a magnesium compound in silicate solution |
| WO2012037024A2 (en) | 2010-09-16 | 2012-03-22 | Georgia-Pacific Consumer Products Lp | High brightness pulps from lignin rich waste papers |
Also Published As
| Publication number | Publication date |
|---|---|
| JPS60181391A (en) | 1985-09-17 |
| FR2557605B1 (en) | 1987-12-11 |
| FI76135B (en) | 1988-05-31 |
| DE148712T1 (en) | 1986-01-02 |
| AU3724384A (en) | 1985-07-04 |
| FR2557605A1 (en) | 1985-07-05 |
| ES539151A0 (en) | 1985-11-16 |
| AU567787B2 (en) | 1987-12-03 |
| JPS6261716B2 (en) | 1987-12-23 |
| EP0148712B1 (en) | 1987-09-09 |
| DE3466024D1 (en) | 1987-10-15 |
| ES8602173A1 (en) | 1985-11-16 |
| FI845121A0 (en) | 1984-12-27 |
| CA1262805A (en) | 1989-11-14 |
| ATE29537T1 (en) | 1987-09-15 |
| FI76135C (en) | 1992-04-15 |
| FI845121L (en) | 1985-06-30 |
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