JPH0217679B2 - - Google Patents
Info
- Publication number
- JPH0217679B2 JPH0217679B2 JP58011603A JP1160383A JPH0217679B2 JP H0217679 B2 JPH0217679 B2 JP H0217679B2 JP 58011603 A JP58011603 A JP 58011603A JP 1160383 A JP1160383 A JP 1160383A JP H0217679 B2 JPH0217679 B2 JP H0217679B2
- Authority
- JP
- Japan
- Prior art keywords
- treatment
- pulp
- acid
- peroxide
- solution
- 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 - Lifetime
Links
- 238000000034 method Methods 0.000 claims description 42
- MHAJPDPJQMAIIY-UHFFFAOYSA-N Hydrogen peroxide Chemical compound OO MHAJPDPJQMAIIY-UHFFFAOYSA-N 0.000 claims description 37
- 239000000243 solution Substances 0.000 claims description 24
- 150000002978 peroxides Chemical class 0.000 claims description 23
- QAOWNCQODCNURD-UHFFFAOYSA-N Sulfuric acid Chemical compound OS(O)(=O)=O QAOWNCQODCNURD-UHFFFAOYSA-N 0.000 claims description 20
- 239000002253 acid Substances 0.000 claims description 18
- HEMHJVSKTPXQMS-UHFFFAOYSA-M Sodium hydroxide Chemical compound [OH-].[Na+] HEMHJVSKTPXQMS-UHFFFAOYSA-M 0.000 claims description 15
- 238000010306 acid treatment Methods 0.000 claims description 15
- 229920001131 Pulp (paper) Polymers 0.000 claims description 12
- 239000003513 alkali Substances 0.000 claims description 3
- 239000012670 alkaline solution Substances 0.000 claims description 3
- 150000007522 mineralic acids Chemical class 0.000 claims description 2
- 150000007524 organic acids Chemical class 0.000 claims description 2
- 238000004061 bleaching Methods 0.000 description 12
- 239000002655 kraft paper Substances 0.000 description 12
- 230000008569 process Effects 0.000 description 11
- 150000001768 cations Chemical class 0.000 description 10
- QVGXLLKOCUKJST-UHFFFAOYSA-N atomic oxygen Chemical compound [O] QVGXLLKOCUKJST-UHFFFAOYSA-N 0.000 description 8
- 230000000694 effects Effects 0.000 description 8
- 239000001301 oxygen Substances 0.000 description 8
- 229910052760 oxygen Inorganic materials 0.000 description 8
- 239000002023 wood Substances 0.000 description 8
- 229910052751 metal Inorganic materials 0.000 description 7
- 239000002184 metal Substances 0.000 description 7
- OSVXSBDYLRYLIG-UHFFFAOYSA-N dioxidochlorine(.) Chemical compound O=Cl=O OSVXSBDYLRYLIG-UHFFFAOYSA-N 0.000 description 6
- 229920005610 lignin Polymers 0.000 description 5
- ZAMOUSCENKQFHK-UHFFFAOYSA-N Chlorine atom Chemical compound [Cl] ZAMOUSCENKQFHK-UHFFFAOYSA-N 0.000 description 4
- VEXZGXHMUGYJMC-UHFFFAOYSA-N Hydrochloric acid Chemical compound Cl VEXZGXHMUGYJMC-UHFFFAOYSA-N 0.000 description 4
- CDBYLPFSWZWCQE-UHFFFAOYSA-L Sodium Carbonate Chemical compound [Na+].[Na+].[O-]C([O-])=O CDBYLPFSWZWCQE-UHFFFAOYSA-L 0.000 description 4
- 239000000460 chlorine Substances 0.000 description 4
- 229910052801 chlorine Inorganic materials 0.000 description 4
- 239000004155 Chlorine dioxide Substances 0.000 description 3
- 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 3
- LSNNMFCWUKXFEE-UHFFFAOYSA-N Sulfurous acid Chemical compound OS(O)=O LSNNMFCWUKXFEE-UHFFFAOYSA-N 0.000 description 3
- 230000002378 acidificating effect Effects 0.000 description 3
- 230000008901 benefit Effects 0.000 description 3
- 235000019398 chlorine dioxide Nutrition 0.000 description 3
- 239000011121 hardwood Substances 0.000 description 3
- 238000004519 manufacturing process Methods 0.000 description 3
- 238000007655 standard test method Methods 0.000 description 3
- 239000000126 substance Substances 0.000 description 3
- 241001070947 Fagus Species 0.000 description 2
- 235000010099 Fagus sylvatica Nutrition 0.000 description 2
- XEEYBQQBJWHFJM-UHFFFAOYSA-N Iron Chemical compound [Fe] XEEYBQQBJWHFJM-UHFFFAOYSA-N 0.000 description 2
- KFSLWBXXFJQRDL-UHFFFAOYSA-N Peracetic acid Chemical compound CC(=O)OO KFSLWBXXFJQRDL-UHFFFAOYSA-N 0.000 description 2
- NBIIXXVUZAFLBC-UHFFFAOYSA-N Phosphoric acid Chemical compound OP(O)(O)=O NBIIXXVUZAFLBC-UHFFFAOYSA-N 0.000 description 2
- ZLMJMSJWJFRBEC-UHFFFAOYSA-N Potassium Chemical compound [K] ZLMJMSJWJFRBEC-UHFFFAOYSA-N 0.000 description 2
- 230000009471 action Effects 0.000 description 2
- 239000007864 aqueous solution Substances 0.000 description 2
- 239000007844 bleaching agent Substances 0.000 description 2
- 229920002678 cellulose Polymers 0.000 description 2
- 239000001913 cellulose Substances 0.000 description 2
- 239000003795 chemical substances by application Substances 0.000 description 2
- 238000010411 cooking Methods 0.000 description 2
- WPBNNNQJVZRUHP-UHFFFAOYSA-L manganese(2+);methyl n-[[2-(methoxycarbonylcarbamothioylamino)phenyl]carbamothioyl]carbamate;n-[2-(sulfidocarbothioylamino)ethyl]carbamodithioate Chemical compound [Mn+2].[S-]C(=S)NCCNC([S-])=S.COC(=O)NC(=S)NC1=CC=CC=C1NC(=S)NC(=O)OC WPBNNNQJVZRUHP-UHFFFAOYSA-L 0.000 description 2
- 229910021645 metal ion Inorganic materials 0.000 description 2
- 239000011591 potassium Substances 0.000 description 2
- 229910052700 potassium Inorganic materials 0.000 description 2
- 239000000376 reactant Substances 0.000 description 2
- 238000011084 recovery Methods 0.000 description 2
- LCPVQAHEFVXVKT-UHFFFAOYSA-N 2-(2,4-difluorophenoxy)pyridin-3-amine Chemical compound NC1=CC=CN=C1OC1=CC=C(F)C=C1F LCPVQAHEFVXVKT-UHFFFAOYSA-N 0.000 description 1
- 239000004343 Calcium peroxide Substances 0.000 description 1
- BVKZGUZCCUSVTD-UHFFFAOYSA-L Carbonate Chemical compound [O-]C([O-])=O BVKZGUZCCUSVTD-UHFFFAOYSA-L 0.000 description 1
- 229920003043 Cellulose fiber Polymers 0.000 description 1
- RYGMFSIKBFXOCR-UHFFFAOYSA-N Copper Chemical compound [Cu] RYGMFSIKBFXOCR-UHFFFAOYSA-N 0.000 description 1
- UFHFLCQGNIYNRP-UHFFFAOYSA-N Hydrogen Chemical compound [H][H] UFHFLCQGNIYNRP-UHFFFAOYSA-N 0.000 description 1
- 239000004115 Sodium Silicate Substances 0.000 description 1
- 239000005708 Sodium hypochlorite Substances 0.000 description 1
- 150000007513 acids Chemical class 0.000 description 1
- 229910000147 aluminium phosphate Inorganic materials 0.000 description 1
- 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 description 1
- 150000004056 anthraquinones Chemical class 0.000 description 1
- LHJQIRIGXXHNLA-UHFFFAOYSA-N calcium peroxide Chemical compound [Ca+2].[O-][O-] LHJQIRIGXXHNLA-UHFFFAOYSA-N 0.000 description 1
- 235000019402 calcium peroxide Nutrition 0.000 description 1
- 150000004649 carbonic acid derivatives Chemical class 0.000 description 1
- 239000003054 catalyst Substances 0.000 description 1
- 230000008859 change Effects 0.000 description 1
- 239000013043 chemical agent Substances 0.000 description 1
- 150000001805 chlorine compounds Chemical class 0.000 description 1
- 230000000052 comparative effect Effects 0.000 description 1
- 150000001875 compounds Chemical class 0.000 description 1
- 238000011109 contamination Methods 0.000 description 1
- 238000007796 conventional method Methods 0.000 description 1
- 229910052802 copper Inorganic materials 0.000 description 1
- 239000010949 copper Substances 0.000 description 1
- 238000005260 corrosion Methods 0.000 description 1
- 230000007797 corrosion Effects 0.000 description 1
- 230000003247 decreasing effect Effects 0.000 description 1
- 238000003912 environmental pollution Methods 0.000 description 1
- 238000004880 explosion Methods 0.000 description 1
- 239000001257 hydrogen Substances 0.000 description 1
- 229910052739 hydrogen Inorganic materials 0.000 description 1
- 230000006872 improvement Effects 0.000 description 1
- 229910052742 iron Inorganic materials 0.000 description 1
- 229910001437 manganese ion Inorganic materials 0.000 description 1
- 150000002739 metals Chemical class 0.000 description 1
- 239000000203 mixture Substances 0.000 description 1
- 230000007935 neutral effect Effects 0.000 description 1
- 235000005985 organic acids Nutrition 0.000 description 1
- 239000000123 paper Substances 0.000 description 1
- 230000002265 prevention Effects 0.000 description 1
- 230000001737 promoting effect Effects 0.000 description 1
- 230000035484 reaction time Effects 0.000 description 1
- 239000011347 resin Substances 0.000 description 1
- 229920005989 resin Polymers 0.000 description 1
- SUKJFIGYRHOWBL-UHFFFAOYSA-N sodium hypochlorite Chemical compound [Na+].Cl[O-] SUKJFIGYRHOWBL-UHFFFAOYSA-N 0.000 description 1
- 229960001922 sodium perborate Drugs 0.000 description 1
- CHQMHPLRPQMAMX-UHFFFAOYSA-L sodium persulfate Substances [Na+].[Na+].[O-]S(=O)(=O)OOS([O-])(=O)=O CHQMHPLRPQMAMX-UHFFFAOYSA-L 0.000 description 1
- NTHWMYGWWRZVTN-UHFFFAOYSA-N sodium silicate Chemical compound [Na+].[Na+].[O-][Si]([O-])=O NTHWMYGWWRZVTN-UHFFFAOYSA-N 0.000 description 1
- 229910052911 sodium silicate Inorganic materials 0.000 description 1
- YKLJGMBLPUQQOI-UHFFFAOYSA-M sodium;oxidooxy(oxo)borane Chemical compound [Na+].[O-]OB=O YKLJGMBLPUQQOI-UHFFFAOYSA-M 0.000 description 1
- LSNNMFCWUKXFEE-UHFFFAOYSA-L sulfite Chemical class [O-]S([O-])=O LSNNMFCWUKXFEE-UHFFFAOYSA-L 0.000 description 1
- -1 sulfite anhydride Chemical class 0.000 description 1
- 150000003467 sulfuric acid derivatives Chemical class 0.000 description 1
- 238000005406 washing Methods 0.000 description 1
- 239000002699 waste material 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
-
- 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
- D21C9/1005—Pretreatment of the pulp, e.g. degassing the pulp
Landscapes
- Life Sciences & Earth Sciences (AREA)
- Engineering & Computer Science (AREA)
- Wood Science & Technology (AREA)
- Paper (AREA)
Description
本発明は製紙用ケミカルパルプ（chemical
paper pulp）の新規な処理方法に関する。
本明細書において“ケミカルパルプ”という用
語は、酸性、中性またはアルカリ性亜硫酸塩、硫
酸塩（クラフト法）、ソーダ、炭酸塩または酸素
および場合により脱リグニン触媒を使用する方法
により得られた、かつ、漂白または明色化
（lightening）されていない、すなわち未だリグ
ニンを含有しているセルロースパルプを意味す
る。
従来から知られている通り、セルロースパルプ
の漂白処理は、高度に縮合した形のかつ蒸解反応
において著しく変性されるリグニンからその大部
分が構成される、かつセルロース繊維と結合して
いる着色物質を化学薬剤の作用により除去する処
理である。ケミカルパルプの漂白は殆んどの場
合、塩素、二酸化塩素または次亜塩素塩ナトリウ
ムのごとき塩素含有薬剤により行われる。
しかしながら、これらの漂白剤は汚染防止とい
う点から大きな不利益を有する。実際、漂白工程
からの廃液を、木材をパルプ化するために使用す
る化学薬品の回収回路に再循環させた場合、この
廃液中に極めて大量の塩素が存在するため、重大
な問題（すなわち、装置の腐蝕の危険性およびボ
イラーの爆発の危険性）が生ずる。
これらの問題を解決するために、塩素を含まな
い薬剤を漂白に使用することが提案されている。
この場合には、漂白処理から生ずる廃液を、塩化
物の使用により生ずる危険性を招来することなし
に、回収しかつ上記漂白剤の回収回路に再循環さ
せ得る。最初の段階においては酸素を漂白剤とし
て使用することが提案された。この方法によれ
ば、この方法は漂白操作により生ずる汚染を減少
させることができ、かつ、何らかの危険性も招来
することがないので、満足すべき結果が得られ
る。しかしながら、酸素を使用する処理はかなり
の設備投資を必要とし、このことがこの方法が限
られた範囲でしか実施されていないことの原因と
なつている。
この本質的に経済的に不利益を除去するため
に、酸素を過酸化物、特に過酸化水素で置き換え
ることも提案されている。この方法は大気圧下に
おいて、従つてより簡単な慣用の漂白装置中で行
うことができるという利点を有しており、このこ
とにより設備投資が酸素法に必要なものより非常
に少ないものになる。過酸化水素処理はクラフト
法ケミカルパルプを製造するための装置および亜
硫酸法によりパルプを製造するためのある種の装
置において使用されている。しかしながら、過酸
化水素は酸素より非常に高価な化学薬品であり、
また、許容され得る経済的条件下では酸素処理に
おけるごとき性能を生じ得ないことが知られてい
る。
実際、ケミカルパルプ中に存在する金属カチオ
ンが過酸化水素を分解し、その結果、過酸化水素
処理の効率が減少ることが知られている。負の効
果を有する、従つてより少量になるまで除去する
ことを必要とる金属カチオンは主としてマンガ
ン、銅および鉄であることが知られている。
過酸化水素処理の効率を向上させるために、こ
の処理を行う前に酸による予備処理を行うことが
提案されている（特開昭51−102103号明細書；フ
ランス特許第2398839号明細書、特に第６頁，第
25行；“Paperi ja puo”、No.4A，1981，第301―
308頁、特に第305頁の表および1981年４月27日―
29日、New Orleansで開催の1981年、TAPPI
ENVIRONMETAL CONFERENC 予稿集、
第93―101頁参照）。
これらの文献に従つて、過酸化水素処理の前に
周囲温度でパルプの酸処理を行うことにより、負
の効果を有する金属カチオンの量が実質的に減少
する。この処理で使用するのに好ましい酸の一つ
は硫酸である。例えば、周囲温度での硫酸による
予備処理は、負の効果を有するカチオン、特に、
最も有害な金属カチオンであると認められるマン
ガンの量を減少させるのに非常に効果があること
が示されている。
今般、全く予想外なことに、過酸化水素処理の
前に行う酸処理を上昇温度で行つた場合には、金
属カチオンの除去の程度は実質的に改善されない
にも拘わらず、酸処理に続いて行われる過酸化水
素を用いる処理の効率が増大し、しかも、得られ
たパルプの機械的性質は保持されることを知見し
た。
換言すれば、過酸化物、特に過酸化水素による
ケミカルパルプの処理の効率は、パルプ中に存在
する有害な金属を除去することだけを目的とする
従来の文献に記載の方法以外の方法により改善し
得る。
従つて本発明によれば、酸溶液を用いて第１の
処理を行についでアルカリ性過酸化物溶液を用い
て第２の処理を行うことからなる製紙用ケミカル
パルプの処理方法において、第１の酸処理を少な
くとも60℃の温度であつてかつ100℃以下の温度
で行なうこと及び第２の処理に用いるアルカリ性
過酸化物溶液が１〜10重量％の過酸化物と１〜10
重量％のアルカリを含有することを特徴とする、
製紙用ケミカルパルプの処理方法が提供される。
第１の処理は60〜80℃の温度で行うことが有利
ある。理論的にはの処理を約100℃以上の温度で
も行い得るが、かかる高温を使用する場合には操
作を加圧下で行うことが必要となり、その場合、
特殊な、高価な装置を必要とし、また、特にパル
プに損傷を与える危険性が生ずる。
負の効果を有するカチオンの濃度を減少させる
ための従来既知の方法を行う際に、処理温度を上
昇させた場合には、この温度の上昇はパルプ中に
含されている有害なカチオンの除去率には顕著な
影響を与えないのに対し、処理されたパルプ中の
リグニン濃度は著しく減少るということは予想し
得なかつたことであり、これは本発明の予期し得
なかつた効果である。
換言すれば、既知の酸処理の温度を上昇させた
場合には、負の効果を有するカチオンの濃度の減
少という点では周囲温度で酸処理を行つた場合と
同一の結果が得られるが、本発明に従つて酸処理
を行うことによりパルプの脱リグニンはより良好
に行われる。以下においてはパルプの残留リグニ
ン濃度はカツパー価（AFNOR標準試験法
NFT12018）により表わす。
前記したごとく、本発明に従つて処理し得るケ
ミカルパルプの種類は広い範囲で変化させ得る。
その例としてはクラフトパルプ、ソーダパルプ、
亜硫酸パルプ、ソーダ／酸素パルプ、ソーダ／ア
ントラキノンパルプおよび炭酸塩パルプが挙げら
れる。
これらのパルプは、本発明に従つて、特に使用
する装置に応じて種々の濃度（consistency）に
おいて処理し得る。この濃度は通常３〜20％であ
るが、処理中は実際には約10〜15％である。
酸処理においては種々の酸溶液を使用し得る
（前記“Paperi ja puo”、No.4A，1981，第305頁
の表参照）。亜硫酸（H2SO3）、塩酸（HCl）、燐
酸（H3PO4）のごとき無機酸を使用することが
有利である。実際には主として硫酸が使用され
る。
所望に応じ有機酸を使用することができ、この
場合、処理回路に容易に再循環し得るという利点
がある。
二酸化塩素を製造するための工場で得られるか
つ硫酸を含有する酸溶液、漂白パルプSO2で処理
する際に生ずる流出液または酸性の漂白流出液の
ごとき、工場で得られる酸性流出液の任意のもの
も使用し得る。以下においては特に説明のない限
り、反応剤の濃度は、処理されたパルプの重量に
対る純粋な反応剤の重量（乾燥重量）を表わす。
酸の濃度は１〜５、好ましくは２〜３のPHが得ら
れるように調節する。酸処理の時間は既知の方法
に従つて30〜180分、好ましくは60〜120分とす
る。
前述したごとく、酸処理の温度は少なくとも60
℃、好ましくは60〜80℃である。
本発明による処理は追加の設備投資を要するこ
となしに、任意慣用のパルプ製造装置中で行い得
る。例えば酸溶液を蒸煮後のパルプのための最後
の洗浄用フイルターのランプ（ramp）に供給し
ついでかく含浸されたパルプを温度および酸の作
用に対して耐久性の慣用の塔に移送する。ついで
酸で処理されたパルプを洗浄し、既知の方法によ
りアルカリ性過酸化物溶液で処理する。
この第２の処理においては過酸化物として一般
式Ｒ―Ｏ―Ｏ―Ｘ（Ｒは基を表わし、Ｘは金属イ
オンまたは水素を表わす）の化合物を使用する。
過酸化物としては例えば過酸化水素、あるいは、
過酸化カリウムまたはカルシウム、過ホウ酸ナト
リウム、過硫酸カリウムまたはナトリウム、過酢
酸のごとき他の有機または無機過酸化物を使用し
得る。工業的な方法においては過酸化水素を使用
することが好ましい。過酸化物の使用量は１〜10
％、好ましくは１〜５％である。前記したごと
く、第２処理の溶液もアルカリを含有する。実際
には、この処理液は１〜10％、好ましくは１〜４
％の水酸化ナトリウムを含有する。
アルカリ性過酸化物を使用する処理は50〜100
℃、好ましくは60〜80℃の温度において0.5〜５
時間、好ましくは１〜３時間行われる。
従つて、すでに述べたごとく、この処理は大気
圧下で行うことが有利である。
この第２の処理の後に、慣用の方法において行
われる水洗を行つてもよくあるいは行わなくても
よい。
ついでかく処理されたパルプに通常の方法で追
加的な漂白処理を行い得る。
本発明の方法および本発明の方法により得られ
る有利な結果は以下に示す実施例から明らかにな
るであろう。処理条件および得られた結果は第
表および第表に示されている。第表はカツパ
―価31の樹脂質木材（resinous wood）から得ら
れれたクラフトパルプの処理に関するものであ
り、一方、第表はカツパー価22の広葉樹木材
（ブナ）（beech）から得られたクラフトパルプの
処理に関するものである。
比較例として示した実施例１においてはカツパ
―価31の樹脂質クラフトパルプの処理を、過酸化
水素のアルカリ性溶液を使用して慣用の方法に従
つて一工程で行つた。
実施例２においては実施例１と同一のパルプを
実施例１と同一のアルカリ性過酸化水素溶液を用
いて処理したが、この場合には上記のアルカリ性
過酸化水素溶液による処理を行う前に公知の方
法、特に特開昭51−102103号明細書に記載の方法
に従つて酸処理を行つた。
酸処理により当初パルプに含有されていた金属
イオン、特にマンガンイオンの相当の量が除去さ
れ、その結果、過酸化物による脱リグニンが促進
されることが判るであろう。
実施例３〜10においては、実施例１と同一の樹
脂木材からのクラフトパルプの処理を本発明の方
法に従つて、かつ、第１処理の温度条件と酸濃度
を変化させ、また、第２処理の過酸化水素の濃度
を変えて行つた。実施例３，４および10を比較す
ると、第１処理の温度を上昇させた場合には、有
害な金属カチオンの除去に対しては顕著な効果は
認められないのに対し、第１処理の酸の濃度およ
び第２処理の過酸化物の濃度を増大させなくても
脱リグニンの程度が著しく改善されることが判
る。
実施例11と12とを比較すると、酸処理の温度を
上昇させることにより広葉樹からのパルプの脱リ
グニンについても同一の効果が得られることが判
る。
指針として示すと、実施例２の処理により実施
例４で得られるカツパー価と同一のカツパー価を
有するパルプを得るためには、第２処理における
過酸化物の濃度を２％だけ余分に増大させること
が必要であるが、このことは経済的な観点からは
極めて不利である。
第表に未漂白原料パルプの機械的特性と、本
発明の方法（実施例４の方法）に従つて処理した
パルプ、すなわち
―第１工程において２％硫酸溶液を用いて70℃で
２時間処理し、ついで
―第２工程において１％の過酸化水素と1.5％の
水酸化ナトリウムとを含有する溶液を用いて90
℃で90分間処理
して得られたパルプの機械的性質を示す。
これらの機械的性質はパルプをWEVERK実験
用グレーダー（0.15mmスロツト）中で等級分け
（grade）しついでJOKROミル中で40゜SRまで精
砕した後、AFNOR標準試験法に従つて測定し
た。第表から、本発明に従つて処理したパルプ
は、未処理の未漂白クラフトパルプと同一の機械
的性質を有することが明らかであ。換言すれば、
酸処理の温度を上昇させた場合に予想れていたこ
とに反して、本発明による処理はこれらのパルプ
の機械的性質を変化させないことが判る。
実施例５と６においては第１処理で使用する酸
溶液中の硫酸濃度を変化させた。実施例７，８お
よび９においては、第２処理で使用する溶液中の
過酸化物濃度を変化させた。
The present invention applies to chemical pulp for paper making.
paper pulp). The term "chemical pulp" as used herein refers to pulps obtained by processes using acidic, neutral or alkaline sulfites, sulfates (Kraft process), soda, carbonates or oxygen and optionally delignification catalysts, and , meaning cellulose pulp that has not been bleached or lightened, ie still contains lignin. As is known in the past, the bleaching treatment of cellulose pulp removes the colored substances, which are mostly composed of lignin, which is in highly condensed form and is highly modified in the cooking reaction, and which is bound to the cellulose fibers. This is a process in which it is removed by the action of chemical agents. Bleaching of chemical pulp is most often carried out with chlorine-containing agents such as chlorine, chlorine dioxide or sodium hypochlorite. However, these bleaches have significant disadvantages in terms of stain prevention. In fact, if the effluent from the bleaching process were to be recirculated into the recovery circuit of the chemicals used to pulp the wood, the presence of extremely high amounts of chlorine in this effluent would cause serious problems (i.e. corrosion hazard and boiler explosion hazard). To solve these problems, it has been proposed to use chlorine-free agents for bleaching.
In this case, the waste liquor resulting from the bleaching process can be recovered and recycled to the bleach recovery circuit without incurring the risks caused by the use of chlorides. In the first stage it was proposed to use oxygen as a bleaching agent. According to this method, satisfactory results are obtained since the method can reduce the contamination caused by the bleaching operation and does not introduce any risks. However, processing using oxygen requires considerable capital investment, which is the reason why this method is only practiced to a limited extent. In order to eliminate this essential economic disadvantage, it has also been proposed to replace oxygen with peroxides, especially hydrogen peroxide. This process has the advantage that it can be carried out at atmospheric pressure and therefore in simpler conventional bleaching equipment, which makes the capital investment much lower than that required for the oxygen process. . Hydrogen peroxide treatment is used in equipment for producing Kraft chemical pulp and in certain equipment for producing pulp by the sulfite process. However, hydrogen peroxide is a much more expensive chemical than oxygen;
It is also known that such performance in oxygen treatment cannot be achieved under acceptable economic conditions. In fact, it is known that metal cations present in chemical pulp decompose hydrogen peroxide, thereby reducing the efficiency of hydrogen peroxide treatment. It is known that the metal cations which have a negative effect and therefore need to be removed to smaller quantities are mainly manganese, copper and iron. In order to improve the efficiency of hydrogen peroxide treatment, it has been proposed to carry out a pretreatment with an acid before carrying out this treatment (Japanese Patent Laid-open No. 102103/1983; French Patent No. 2398839, in particular Page 6, no.
Line 25; “Paperi ja puo”, No. 4A, 1981, No. 301.
Page 308, especially the table on page 305 and April 27, 1981.
1981 TAPPI held in New Orleans on the 29th
ENVIRONMETAL CONFERENC Proceedings,
(See pages 93-101). According to these documents, acid treatment of the pulp at ambient temperature prior to hydrogen peroxide treatment substantially reduces the amount of metal cations that have a negative effect. One of the preferred acids for use in this treatment is sulfuric acid. For example, pretreatment with sulfuric acid at ambient temperature removes cations that have a negative effect, in particular
It has been shown to be very effective in reducing the amount of manganese, which is recognized as the most harmful metal cation. Now, quite unexpectedly, it has been found that when acid treatment is carried out at elevated temperatures prior to hydrogen peroxide treatment, the extent of metal cation removal is not substantially improved; It has been found that the efficiency of the treatment with hydrogen peroxide carried out is increased, yet the mechanical properties of the resulting pulp are preserved. In other words, the efficiency of the treatment of chemical pulp with peroxides, especially hydrogen peroxide, can be improved by methods other than those described in the conventional literature, which are only aimed at removing harmful metals present in the pulp. It is possible. Therefore, according to the present invention, in the method for treating chemical pulp for papermaking, which comprises performing a first treatment using an acid solution and then performing a second treatment using an alkaline peroxide solution, the first treatment The acid treatment is carried out at a temperature of at least 60°C and not more than 100°C, and the alkaline peroxide solution used in the second treatment contains 1 to 10% by weight of peroxide and 1 to 10% by weight of peroxide.
characterized by containing % by weight of alkali,
A method of treating chemical pulp for papermaking is provided. Advantageously, the first treatment is carried out at a temperature of 60 to 80°C. Theoretically, the process could be carried out at temperatures above about 100°C, but the use of such high temperatures would require the operation to be carried out under pressure, in which case
Special, expensive equipment is required and, in particular, there is a risk of damage to the pulp. When carrying out conventionally known methods for reducing the concentration of cations with negative effects, if the processing temperature is increased, this increase in temperature will increase the removal rate of harmful cations contained in the pulp. It was unexpected that the lignin concentration in the treated pulp was significantly reduced while the lignin concentration was not significantly affected, and this is an unexpected effect of the present invention. In other words, increasing the temperature of the known acid treatment yields the same results as performing the acid treatment at ambient temperature in terms of reducing the concentration of cations that have negative effects, but this By carrying out the acid treatment according to the invention, the pulp is better delignified. In the following, the residual lignin concentration of the pulp is determined by the Katsupar number (AFNOR standard test method).
NFT12018). As mentioned above, the type of chemical pulp that can be treated according to the present invention can vary over a wide range.
Examples include kraft pulp, soda pulp,
Mention may be made of sulfite pulp, soda/oxygen pulp, soda/anthraquinone pulp and carbonate pulp. These pulps can be processed according to the invention at different consistencies, depending in particular on the equipment used. This concentration is normally 3-20%, but in practice it is about 10-15% during processing. Various acid solutions can be used in the acid treatment (see table in the above-mentioned "Paperi ja puo", No. 4A, 1981, page 305). It is advantageous to use inorganic acids such as sulfurous acid (H 2 SO 3 ), hydrochloric acid (HCl), phosphoric acid (H 3 PO 4 ). In practice, sulfuric acid is mainly used. Organic acids can be used if desired, with the advantage that they can be easily recycled to the processing circuit. Any acidic effluent obtained in a factory, such as an acid solution obtained in a factory for the production of chlorine dioxide and containing sulfuric acid, an effluent resulting from the treatment of bleached pulp with SO 2 or an acidic bleaching effluent; can also be used. In the following, unless otherwise stated, the concentration of reactant refers to the weight of pure reactant (dry weight) relative to the weight of treated pulp.
The concentration of acid is adjusted to obtain a pH of 1-5, preferably 2-3. The acid treatment time is from 30 to 180 minutes, preferably from 60 to 120 minutes, according to known methods. As mentioned above, the acid treatment temperature is at least 60℃.
℃, preferably 60-80℃. The treatment according to the invention can be carried out in any conventional pulp manufacturing equipment without requiring additional capital investment. For example, an acid solution is fed to the ramp of the last washing filter for the pulp after cooking and the pulp thus impregnated is transferred to a conventional column resistant to temperature and acid action. The acid-treated pulp is then washed and treated with an alkaline peroxide solution according to known methods. In this second treatment, a compound of the general formula R-O-O-X (R represents a group and X represents a metal ion or hydrogen) is used as a peroxide.
Examples of peroxides include hydrogen peroxide, or
Other organic or inorganic peroxides may be used such as potassium or calcium peroxide, sodium perborate, potassium or sodium persulfate, peracetic acid. Preference is given to using hydrogen peroxide in industrial processes. The amount of peroxide used is 1 to 10
%, preferably 1 to 5%. As described above, the solution for the second treatment also contains an alkali. In practice, this treatment solution should be 1-10%, preferably 1-4%
Contains % sodium hydroxide. Treatment using alkaline peroxide is 50-100
℃, preferably 0.5 to 5 at a temperature of 60 to 80℃
The reaction time is preferably 1 to 3 hours. Therefore, as already mentioned, it is advantageous to carry out this treatment under atmospheric pressure. This second treatment may or may not be followed by a conventional water wash. The pulp thus treated may then be subjected to an additional bleaching treatment in the usual manner. The method of the invention and the advantageous results obtained with it will become clear from the examples given below. The processing conditions and results obtained are shown in Tables 1 and 2. The table relates to the treatment of kraft pulp obtained from resinous wood with a cut par number of 31, while the table relates to the treatment of kraft pulp obtained from hardwood wood (beech) with a cut par number of 22. It concerns the treatment of pulp. In Example 1, shown as a comparative example, a resinous kraft pulp having a cut par number of 31 was treated in one step using an alkaline solution of hydrogen peroxide according to a conventional method. In Example 2, the same pulp as in Example 1 was treated using the same alkaline hydrogen peroxide solution as in Example 1, but in this case, prior to treatment with the above alkaline hydrogen peroxide solution, a known method was used. The acid treatment was carried out according to the method described in JP-A-51-102103. It will be seen that the acid treatment removes a significant amount of the metal ions, particularly manganese ions, originally contained in the pulp, thereby promoting peroxide delignification. In Examples 3 to 10, kraft pulp from the same resinous wood as in Example 1 was treated according to the method of the present invention, and the temperature conditions and acid concentration of the first treatment were varied, and the second treatment was carried out in accordance with the method of the present invention. The treatment was carried out by varying the concentration of hydrogen peroxide. Comparing Examples 3, 4, and 10, when the temperature of the first treatment was increased, no significant effect was observed on the removal of harmful metal cations, whereas when the temperature of the first treatment was increased, the acid It can be seen that the degree of delignification is significantly improved even without increasing the concentration of peroxide and the concentration of peroxide in the second treatment. A comparison of Examples 11 and 12 shows that the same effect can be obtained on the delignification of pulp from hardwoods by increasing the temperature of acid treatment. As a guideline, in order to obtain a pulp with the same Kappa number as that obtained in Example 4 by the treatment of Example 2, the peroxide concentration in the second treatment should be increased by an extra 2%. However, this is extremely disadvantageous from an economic point of view. Table 1 shows the mechanical properties of the unbleached raw pulp and the pulp treated according to the method of the present invention (the method of Example 4), namely - in the first step treated with a 2% sulfuric acid solution at 70°C for 2 hours. Then - in the second step, using a solution containing 1% hydrogen peroxide and 1.5% sodium hydroxide
The mechanical properties of the pulp obtained by processing at °C for 90 minutes are shown. These mechanical properties were determined according to the AFNOR standard test method after the pulp was graded in a WEVERK laboratory grader (0.15 mm slot) and refined to 40° SR in a JOKRO mill. From the table it is clear that the pulp treated according to the invention has the same mechanical properties as untreated unbleached kraft pulp. In other words,
It can be seen that, contrary to what would have been expected if the temperature of the acid treatment was increased, the treatment according to the invention does not change the mechanical properties of these pulps. In Examples 5 and 6, the sulfuric acid concentration in the acid solution used in the first treatment was varied. In Examples 7, 8, and 9, the peroxide concentration in the solution used in the second treatment was varied.
【表】【table】
【表】【table】
【表】【table】
【表】【table】
【表】
実施例 13
実施例４で使用したものと同一の樹脂質木材か
らのクラフトパルプを同実施例と同一の方法で処
理した後、すなわち、70℃で第１処理を行いつい
で過酸化物処理した後、使用した。上記の処理を
行つたパルプについて再び同一の処理を行つた；
すなわち、
―第１工程においては、２％硫酸水溶液を使用し
て70℃で２時間処理し、ついで
―第２工程においては、１重量％の過酸化水素と
1.5重量％の水酸化ナトリウムとを含有するア
ルカリ性過酸化物溶液を使用して90℃で90分、
濃度12％のパルプを処理した。
この方法においてはカツパー価が18.5から11.0
に減少した、かつ白色度（AFNOR標準試験法
NFQ03039に従つて測定）が58％のパルプが得ら
れた；機械的性質に変化はなかつた。
実施例 14
樹脂木材からのクラフトパルプとして、実施例
12で使用したものと同一の、広葉樹木材（ブナ）
からのクラフトパルプを使用して実施例13を繰返
した。更に、硫酸水溶液の代りに、１％の硫酸と
２％の無水亜硫酸とを含有する混合物の水溶液を
使用することにより酸の種類を変えた。カツパー
価が12から9.0に減少し、53.5％の白色度が得ら
れた。
実施例 15
実施例４の方法に従つて70℃で処理を行つてカ
ツパー価31の、樹脂質木材のクラフトパルプを製
造した。このパルプについて下記の条件下で二段
階の補充的漂白処理を行つた：
―第１工程―二酸化塩素使用：
ClO2濃度 1.5％
処理温度 70℃
処理時間 60分
パルプ濃度 ６％
―第２工程―過酸化水素使用：
H2O2濃度 1.5％
NaOH濃度 １％
38゜B珪酸ナトリウム濃度 ３％
処理温度 70℃
処理時間 180分
パルプ濃度 10％
例えば、塩素処理を必要としない少工程法
（short process）（４工程）においては87.5％の
白色度が得られ、このことは本発明の方法に従つ
て処理されたパルプはすぐれた漂白特性を有する
ことを示している。
前記したごとく、本発明の方法によれば単に酸
処理の温度を上昇させることにより、設備、価格
および環境汚染に関しての有利な条件下において
脱リグニンの程度が予期し得なかつた程度に改善
され、しかも得られたパルプは良好な機械的性質
と漂白に対するすぐれた適性を有するという理由
で、本発明の方法は多くの利点を有する。[Table] Example 13 Kraft pulp from the same resinous wood as used in Example 4 was treated in the same manner as in Example 4, i.e. a first treatment at 70°C followed by peroxide treatment. Used after processing. The pulp that had undergone the above treatment was again subjected to the same treatment;
That is, - in the first step, a 2% aqueous sulfuric acid solution was used at 70°C for 2 hours, and in the second step, a 1% by weight hydrogen peroxide solution was used.
90 min at 90 °C using an alkaline peroxide solution containing 1.5 wt% sodium hydroxide;
Pulp with a concentration of 12% was treated. In this method, the Katsupar number is 18.5 to 11.0.
and whiteness (AFNOR standard test method)
A pulp of 58% (measured according to NFQ03039) was obtained; the mechanical properties remained unchanged. Example 14 As kraft pulp from resin wood, Example
Hardwood wood (beech), same as that used in 12.
Example 13 was repeated using kraft pulp from Furthermore, the type of acid was changed by using an aqueous solution of a mixture containing 1% sulfuric acid and 2% sulfite anhydride instead of the sulfuric acid aqueous solution. The Katsupar number decreased from 12 to 9.0, and a whiteness of 53.5% was obtained. Example 15 A resinous wood kraft pulp having a cut par value of 31 was produced by treatment at 70° C. according to the method of Example 4. This pulp was subjected to a two-step supplementary bleaching treatment under the following conditions: - First step - Using chlorine dioxide: ClO 2 concentration 1.5% Treatment temperature 70°C Treatment time 60 minutes Pulp concentration 6% - Second step - Using hydrogen peroxide: H 2 O 2 concentration 1.5% NaOH concentration 1% 38°B sodium silicate concentration 3% Treatment temperature 70°C Treatment time 180 minutes Pulp concentration 10% For example, a short process method that does not require chlorine treatment ) (4 steps) a brightness of 87.5% was obtained, indicating that the pulp treated according to the method of the invention has excellent bleaching properties. As mentioned above, the method of the invention provides an unexpected improvement in the degree of delignification by simply increasing the temperature of the acid treatment under advantageous conditions regarding equipment, cost and environmental pollution; Moreover, the process according to the invention has many advantages, since the pulp obtained has good mechanical properties and good suitability for bleaching.
Claims (1)
カリ性過酸化物溶液を用いて第２の処理を行うこ
とからなる製紙用ケミカルパルプの処理方法にお
いて、第１の酸処理を少なくとも60℃の温度であ
つてかつ100℃以下の温度で行うこと及び第２の
処理に用いるアルカリ性過酸化物溶液が１〜10重
量％の過酸化物と１〜10重量％のアルカリを含有
することを特徴とする、製紙用ケミカルパルプの
処理方法。 ２ 第１の処理を60〜80℃の温度で行う、特許請
求の範囲第１項記載の方法。 ３ 第１の処理に用いる酸溶液のPHが１〜５、好
ましくは２〜３である。特許請求の範囲第１項ま
たは第２項記載の方法。 ４ 第１の処理の時間が60〜120分である、特許
請求の範囲第１項〜第３項のいずれかに記載の方
法。 ５ 酸溶液が無機酸または有機酸を含有する、特
許請求の範囲第１項〜第４項のいずれかに記載の
方法。 ６ 酸溶液が硫酸を含有する、特許請求の範囲第
５項記載の方法。 ７ 第２の処理に用いるアルカリ性溶液が１〜10
重量％の過酸化水素を含有する、特許請求の範囲
第１項〜第６項のいずれかに記載の方法。 ８ 第２の処理に用いるアルカリ性溶液が１〜10
重量％の水酸化ナトリウムを含有する、特許請求
の範囲第７項記載の方法。 ９ 熱酸溶液とアルカリ性過酸化物溶液との２種
の溶液を連続的に用いる処理を数回繰返す、特許
請求の範囲第１項〜第８項のいずれかに記載の方
法。[Scope of Claims] 1. A method for treating chemical pulp for papermaking comprising performing a first treatment using an acid solution and then performing a second treatment using an alkaline peroxide solution, wherein the first acid treatment at a temperature of at least 60°C and below 100°C, and the alkaline peroxide solution used in the second treatment contains 1 to 10% by weight of peroxide and 1 to 10% by weight of alkali. A method for processing chemical pulp for papermaking, characterized by: 2. The method according to claim 1, wherein the first treatment is carried out at a temperature of 60 to 80°C. 3. The acid solution used in the first treatment has a pH of 1 to 5, preferably 2 to 3. A method according to claim 1 or 2. 4. The method according to any one of claims 1 to 3, wherein the first treatment time is 60 to 120 minutes. 5. The method according to any one of claims 1 to 4, wherein the acid solution contains an inorganic acid or an organic acid. 6. The method of claim 5, wherein the acid solution contains sulfuric acid. 7 The alkaline solution used for the second treatment is 1 to 10
7. A method according to any of claims 1 to 6, containing % by weight of hydrogen peroxide. 8 The alkaline solution used for the second treatment is 1 to 10
8. A method according to claim 7, containing % by weight of sodium hydroxide. 9. The method according to any one of claims 1 to 8, wherein the treatment using two types of solutions, a hot acid solution and an alkaline peroxide solution, is repeated several times.
Applications Claiming Priority (2)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| FR8201603A FR2520397A1 (en) | 1982-01-28 | 1982-01-28 | PROCESS FOR TREATING CHEMICAL PAPER PASTES |
| FR8201603 | 1982-01-28 |
Publications (2)
| Publication Number | Publication Date |
|---|---|
| JPS58132190A JPS58132190A (en) | 1983-08-06 |
| JPH0217679B2 true JPH0217679B2 (en) | 1990-04-23 |
Family
ID=9270561
Family Applications (1)
| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| JP58011603A Granted JPS58132190A (en) | 1982-01-28 | 1983-01-28 | Treatment of papermaking chemical pulp |
Country Status (16)
| Country | Link |
|---|---|
| JP (1) | JPS58132190A (en) |
| KR (1) | KR850001341B1 (en) |
| AT (1) | AT381736B (en) |
| BE (1) | BE895645A (en) |
| BR (1) | BR8300402A (en) |
| CA (1) | CA1206704A (en) |
| CH (1) | CH653720A5 (en) |
| DE (1) | DE3302580A1 (en) |
| ES (1) | ES519327A0 (en) |
| FI (1) | FI76134C (en) |
| FR (1) | FR2520397A1 (en) |
| IT (1) | IT1162810B (en) |
| NO (1) | NO161391C (en) |
| OA (1) | OA07313A (en) |
| PT (1) | PT76145B (en) |
| SE (1) | SE462288B (en) |
Families Citing this family (19)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CA1227304A (en) * | 1984-08-01 | 1987-09-29 | Raymond C. Francis | Delignification of pulp |
| FR2593527B1 (en) * | 1986-01-30 | 1988-03-25 | Centre Tech Ind Papier | PROCESS FOR BLEACHING MECHANICAL PASTA. |
| DE402335T1 (en) * | 1989-06-06 | 1992-04-09 | Eka Nobel Ab, Surte | METHOD FOR BLEACHING LIGNOCELLULOSE-CONTAINING CELLS. |
| US5091054A (en) * | 1989-08-18 | 1992-02-25 | Degussa Corporation | Process for bleaching and delignification of lignocellulosic |
| US5246543A (en) * | 1989-08-18 | 1993-09-21 | Degussa Corporation | Process for bleaching and delignification of lignocellulosic materials |
| DE3937932A1 (en) * | 1989-11-15 | 1991-05-16 | Holtzmann & Cie Ag E | Delignification and bleaching of pulp with alkali chlorite - by adding chlorite before acidification to produce nascent reagent, minimising pollution |
| SE466061B (en) * | 1990-04-23 | 1991-12-09 | Eka Nobel Ab | Bleaching of chemical pulp by treatment with first a complexing agent and then a peroxide containing substance |
| SE9001481L (en) * | 1990-04-23 | 1991-10-24 | Eka Nobel Ab | REDUCTION OF HALOGEN ORGANIC SUBSTANCES IN BLEACHING WASTE |
| US6398908B1 (en) | 1991-04-30 | 2002-06-04 | Eka Nobel Ab | Process for acid bleaching of lignocellulose-containing pulp with a magnesium compound |
| SE470065C (en) * | 1991-04-30 | 1996-01-15 | Eka Nobel Ab | Treatment of chemical pulp with an acid and then a magnesium and calcium compound in chlorine-free bleaching |
| SE500113C2 (en) * | 1992-07-09 | 1994-04-18 | Kamyr Ab | Method of bleaching pulp for disposal of released metals |
| SE512137C2 (en) * | 1992-10-29 | 2000-01-31 | Eka Chemicals Ab | Process for bleaching lignocellulosic pulp |
| SE9301960L (en) * | 1993-06-08 | 1994-07-25 | Kvaerner Pulping Tech | Bleaching of chemical pulp with peroxide at overpressure |
| US6776876B1 (en) | 1994-10-13 | 2004-08-17 | Andritz Oy | Method of treating cellulosic pulp to remove hexenuronic acid |
| WO1996025552A1 (en) * | 1995-02-17 | 1996-08-22 | Ahlstrom Machinery Oy | Method of pretreating pulp to be bleached with peroxide |
| SE526241C2 (en) * | 2003-12-18 | 2005-08-02 | Metso Paper Inc | Procedure for acidifying lignocellulosic pulp before ozone bleaching |
| US8080560B2 (en) | 2004-12-17 | 2011-12-20 | 3M Innovative Properties Company | Immune response modifier formulations containing oleic acid and methods |
| US8889154B2 (en) | 2005-09-15 | 2014-11-18 | Medicis Pharmaceutical Corporation | Packaging for 1-(2-methylpropyl)-1H-imidazo[4,5-c] quinolin-4-amine-containing formulation |
| US8980051B2 (en) | 2009-04-24 | 2015-03-17 | International Paper Company | Sulfonation of pulp produced by alkali pulping process |
Citations (3)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| JPS51102103A (en) * | 1975-03-05 | 1976-09-09 | Nippon Parupu Kogyo Kk | Ryusanenhoparupuno hyohakuhoho |
| JPS5455606A (en) * | 1977-09-20 | 1979-05-02 | Degussa | Chemical postttreating method and production of needleeleaf pulp for special paper |
| JPS5685489A (en) * | 1979-12-10 | 1981-07-11 | Kogyo Gijutsuin | Pulp production |
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| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| US1705897A (en) * | 1922-03-16 | 1929-03-19 | Bradley Linn | Bleaching of pulp |
| FR1010501A (en) * | 1948-08-31 | 1952-06-12 | Papiers Abadie Sa Des | Cellulose pulp bleaching process |
| US2668095A (en) * | 1950-09-22 | 1954-02-02 | Du Pont | Bleaching chemical paper pulp |
| FR1201712A (en) * | 1958-07-11 | 1960-01-05 | Fr Du Xylon Soc | Cellulose pulp bleaching improvements |
| FR2398839A1 (en) * | 1977-07-29 | 1979-02-23 | Centre Tech Ind Papier | Kraft type paper pulp prepn. without sulphur pollutants - by treating shavings with sodium hydroxide followed by stabilised peroxide |
-
1982
- 1982-01-28 FR FR8201603A patent/FR2520397A1/en active Granted
- 1982-12-22 SE SE8207356A patent/SE462288B/en unknown
- 1982-12-23 KR KR8205769A patent/KR850001341B1/en active
-
1983
- 1983-01-07 IT IT67014/83A patent/IT1162810B/en active
- 1983-01-19 BE BE0/209926A patent/BE895645A/en not_active IP Right Cessation
- 1983-01-25 CA CA000420203A patent/CA1206704A/en not_active Expired
- 1983-01-26 PT PT76145A patent/PT76145B/en not_active IP Right Cessation
- 1983-01-26 DE DE19833302580 patent/DE3302580A1/en active Granted
- 1983-01-27 FI FI830288A patent/FI76134C/en not_active IP Right Cessation
- 1983-01-27 CH CH463/83A patent/CH653720A5/en not_active IP Right Cessation
- 1983-01-27 AT AT0026383A patent/AT381736B/en not_active IP Right Cessation
- 1983-01-27 ES ES519327A patent/ES519327A0/en active Granted
- 1983-01-27 BR BR8300402A patent/BR8300402A/en not_active IP Right Cessation
- 1983-01-27 NO NO830268A patent/NO161391C/en unknown
- 1983-01-28 JP JP58011603A patent/JPS58132190A/en active Granted
- 1983-01-28 OA OA57907A patent/OA07313A/en unknown
Patent Citations (3)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| JPS51102103A (en) * | 1975-03-05 | 1976-09-09 | Nippon Parupu Kogyo Kk | Ryusanenhoparupuno hyohakuhoho |
| JPS5455606A (en) * | 1977-09-20 | 1979-05-02 | Degussa | Chemical postttreating method and production of needleeleaf pulp for special paper |
| JPS5685489A (en) * | 1979-12-10 | 1981-07-11 | Kogyo Gijutsuin | Pulp production |
Also Published As
| Publication number | Publication date |
|---|---|
| SE8207356D0 (en) | 1982-12-22 |
| PT76145B (en) | 1985-11-25 |
| IT8367014A0 (en) | 1983-01-07 |
| AT381736B (en) | 1986-11-25 |
| CH653720A5 (en) | 1986-01-15 |
| FR2520397A1 (en) | 1983-07-29 |
| JPS58132190A (en) | 1983-08-06 |
| NO830268L (en) | 1983-07-29 |
| FI830288L (en) | 1983-07-29 |
| IT1162810B (en) | 1987-04-01 |
| DE3302580C2 (en) | 1992-07-02 |
| BR8300402A (en) | 1983-11-01 |
| NO161391C (en) | 1989-08-09 |
| KR840002934A (en) | 1984-07-21 |
| FR2520397B1 (en) | 1984-03-09 |
| ES8400520A1 (en) | 1983-10-16 |
| SE8207356L (en) | 1983-07-29 |
| SE462288B (en) | 1990-05-28 |
| FI76134C (en) | 1988-09-09 |
| BE895645A (en) | 1983-07-19 |
| DE3302580A1 (en) | 1983-08-04 |
| ES519327A0 (en) | 1983-10-16 |
| FI830288A0 (en) | 1983-01-27 |
| CA1206704A (en) | 1986-07-02 |
| FI76134B (en) | 1988-05-31 |
| KR850001341B1 (en) | 1985-09-19 |
| ATA26383A (en) | 1986-04-15 |
| NO161391B (en) | 1989-05-02 |
| PT76145A (en) | 1983-02-01 |
| OA07313A (en) | 1984-08-31 |
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