JPH0571717B2 - - Google Patents
Info
- Publication number
- JPH0571717B2 JPH0571717B2 JP60019304A JP1930485A JPH0571717B2 JP H0571717 B2 JPH0571717 B2 JP H0571717B2 JP 60019304 A JP60019304 A JP 60019304A JP 1930485 A JP1930485 A JP 1930485A JP H0571717 B2 JPH0571717 B2 JP H0571717B2
- Authority
- JP
- Japan
- Prior art keywords
- acid
- resin
- photochromic
- fibers
- fibrous material
- Prior art date
- Legal status (The legal status is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the status listed.)
- Expired - Fee Related
Links
- 239000000835 fiber Substances 0.000 claims description 18
- 239000002253 acid Substances 0.000 claims description 11
- CMPGARWFYBADJI-UHFFFAOYSA-L tungstic acid Chemical compound O[W](O)(=O)=O CMPGARWFYBADJI-UHFFFAOYSA-L 0.000 claims description 8
- 229920005989 resin Polymers 0.000 claims description 7
- 239000011347 resin Substances 0.000 claims description 7
- 229910052723 transition metal Inorganic materials 0.000 claims description 7
- 150000003624 transition metals Chemical class 0.000 claims description 6
- 229920000877 Melamine resin Polymers 0.000 claims description 5
- 239000004372 Polyvinyl alcohol Substances 0.000 claims description 5
- XSQUKJJJFZCRTK-UHFFFAOYSA-N Urea Chemical compound NC(N)=O XSQUKJJJFZCRTK-UHFFFAOYSA-N 0.000 claims description 5
- 239000004202 carbamide Substances 0.000 claims description 5
- 239000006185 dispersion Substances 0.000 claims description 5
- 239000002657 fibrous material Substances 0.000 claims description 5
- 229920002451 polyvinyl alcohol Polymers 0.000 claims description 5
- 239000000126 substance Substances 0.000 claims description 5
- JDSHMPZPIAZGSV-UHFFFAOYSA-N melamine Chemical compound NC1=NC(N)=NC(N)=N1 JDSHMPZPIAZGSV-UHFFFAOYSA-N 0.000 claims description 4
- VLAPMBHFAWRUQP-UHFFFAOYSA-L molybdic acid Chemical compound O[Mo](O)(=O)=O VLAPMBHFAWRUQP-UHFFFAOYSA-L 0.000 claims description 4
- LSGOVYNHVSXFFJ-UHFFFAOYSA-N vanadate(3-) Chemical compound [O-][V]([O-])([O-])=O LSGOVYNHVSXFFJ-UHFFFAOYSA-N 0.000 claims description 4
- 229920003043 Cellulose fiber Polymers 0.000 claims description 3
- 239000007864 aqueous solution Substances 0.000 claims description 3
- ISWSIDIOOBJBQZ-UHFFFAOYSA-N Phenol Chemical compound OC1=CC=CC=C1 ISWSIDIOOBJBQZ-UHFFFAOYSA-N 0.000 claims description 2
- 238000005520 cutting process Methods 0.000 claims description 2
- WSFSSNUMVMOOMR-UHFFFAOYSA-N Formaldehyde Chemical compound O=C WSFSSNUMVMOOMR-UHFFFAOYSA-N 0.000 description 6
- 150000001875 compounds Chemical class 0.000 description 6
- XLYOFNOQVPJJNP-UHFFFAOYSA-N water Substances O XLYOFNOQVPJJNP-UHFFFAOYSA-N 0.000 description 6
- 239000000243 solution Substances 0.000 description 5
- 238000003756 stirring Methods 0.000 description 5
- VEXZGXHMUGYJMC-UHFFFAOYSA-N Hydrochloric acid Chemical compound Cl VEXZGXHMUGYJMC-UHFFFAOYSA-N 0.000 description 4
- XMVONEAAOPAGAO-UHFFFAOYSA-N sodium tungstate Chemical compound [Na+].[Na+].[O-][W]([O-])(=O)=O XMVONEAAOPAGAO-UHFFFAOYSA-N 0.000 description 4
- NWUYHJFMYQTDRP-UHFFFAOYSA-N 1,2-bis(ethenyl)benzene;1-ethenyl-2-ethylbenzene;styrene Chemical compound C=CC1=CC=CC=C1.CCC1=CC=CC=C1C=C.C=CC1=CC=CC=C1C=C NWUYHJFMYQTDRP-UHFFFAOYSA-N 0.000 description 3
- 238000002845 discoloration Methods 0.000 description 3
- 238000004519 manufacturing process Methods 0.000 description 3
- 239000004640 Melamine resin Substances 0.000 description 2
- 229920001807 Urea-formaldehyde Polymers 0.000 description 2
- 239000003729 cation exchange resin Substances 0.000 description 2
- 229920001429 chelating resin Polymers 0.000 description 2
- 230000000694 effects Effects 0.000 description 2
- 238000005470 impregnation Methods 0.000 description 2
- QSHDDOUJBYECFT-UHFFFAOYSA-N mercury Chemical compound [Hg] QSHDDOUJBYECFT-UHFFFAOYSA-N 0.000 description 2
- 229910052753 mercury Inorganic materials 0.000 description 2
- 239000005011 phenolic resin Substances 0.000 description 2
- 235000013311 vegetables Nutrition 0.000 description 2
- UOFGSWVZMUXXIY-UHFFFAOYSA-N 1,5-Diphenyl-3-thiocarbazone Chemical compound C=1C=CC=CC=1N=NC(=S)NNC1=CC=CC=C1 UOFGSWVZMUXXIY-UHFFFAOYSA-N 0.000 description 1
- 239000004354 Hydroxyethyl cellulose Substances 0.000 description 1
- 229920000663 Hydroxyethyl cellulose Polymers 0.000 description 1
- 229910010413 TiO 2 Inorganic materials 0.000 description 1
- 150000007513 acids Chemical class 0.000 description 1
- 239000012461 cellulose resin Substances 0.000 description 1
- 238000004042 decolorization Methods 0.000 description 1
- 239000011521 glass Substances 0.000 description 1
- 235000019447 hydroxyethyl cellulose Nutrition 0.000 description 1
- 239000003456 ion exchange resin Substances 0.000 description 1
- 229920003303 ion-exchange polymer Polymers 0.000 description 1
- 238000002372 labelling Methods 0.000 description 1
- 239000007788 liquid Substances 0.000 description 1
- 229910052751 metal Inorganic materials 0.000 description 1
- 239000002184 metal Substances 0.000 description 1
- 238000000034 method Methods 0.000 description 1
- 150000002894 organic compounds Chemical class 0.000 description 1
- 239000002952 polymeric resin Substances 0.000 description 1
- 238000006116 polymerization reaction Methods 0.000 description 1
- 229920006316 polyvinylpyrrolidine Polymers 0.000 description 1
- 239000001267 polyvinylpyrrolidone Substances 0.000 description 1
- 229920000036 polyvinylpyrrolidone Polymers 0.000 description 1
- 235000013855 polyvinylpyrrolidone Nutrition 0.000 description 1
- 238000011084 recovery Methods 0.000 description 1
- 230000002441 reversible effect Effects 0.000 description 1
- CMZUMMUJMWNLFH-UHFFFAOYSA-N sodium metavanadate Chemical compound [Na+].[O-][V](=O)=O CMZUMMUJMWNLFH-UHFFFAOYSA-N 0.000 description 1
- 235000015393 sodium molybdate Nutrition 0.000 description 1
- 239000011684 sodium molybdate Substances 0.000 description 1
- TVXXNOYZHKPKGW-UHFFFAOYSA-N sodium molybdate (anhydrous) Chemical compound [Na+].[Na+].[O-][Mo]([O-])(=O)=O TVXXNOYZHKPKGW-UHFFFAOYSA-N 0.000 description 1
- 229920003002 synthetic resin Polymers 0.000 description 1
- 229910000166 zirconium phosphate Inorganic materials 0.000 description 1
Description
【発明の詳細な説明】
産業上の利用分野
本発明は、ホトクロミツク現象を有する遷移金
属酸を、樹脂によりパルプ表面もしくは内部に固
着させたり、樹脂そのものに分散させることによ
つて得られる、高い変色濃度と堅牢度を有するホ
トクロミツク機能を持つ製紙用繊維に関するもの
である。DETAILED DESCRIPTION OF THE INVENTION Field of Industrial Application The present invention is directed to high discoloration, which can be obtained by fixing a transition metal acid having a photochromic phenomenon to the surface or inside of pulp with a resin, or by dispersing it in the resin itself. The present invention relates to papermaking fibers with photochromic functions that have density and fastness.
従来の技術
ホトクロミツク現象は、ある化合物に太陽光又
は紫外線を含む水銀灯で照射すると速やかに変色
し、光の照射を止めて暗所に置くと元の色に戻る
可逆的変色現象のことであり、この性質を有する
化合物にはスピロピラン化合物、ジチゾン金属錯
体及びTiO2をドープしたWO3化合物等があるが、
応用面では非常に限定されている。PRIOR ART Photochromic phenomenon is a reversible discoloration phenomenon in which a compound rapidly changes color when irradiated with sunlight or a mercury lamp containing ultraviolet light, and returns to its original color when the light irradiation is stopped and the compound is placed in a dark place. Compounds with this property include spiropyran compounds, dithizone metal complexes, and TiO 2 doped WO 3 compounds.
It is very limited in terms of application.
発明が解決しようとする問題点
このようなホトクロミツク物質を製紙の段階で
付与すれば、有価証券等の偽造防止対策上有用で
あるが、既知のホトクロミツク物質をそのまま使
用したのでは着色濃度、消変色速度、耐疲労度及
び堅牢性等が劣り、有価証券等の製紙用繊維とし
ての使用には適さなかつた。Problems to be Solved by the Invention If such a photochromic substance is applied at the paper manufacturing stage, it will be useful as a measure to prevent counterfeiting of securities, etc. However, if the known photochromic substance is used as is, the color density and decolorization will be low. It was inferior in speed, fatigue resistance, robustness, etc., and was not suitable for use as paper manufacturing fiber for securities, etc.
本発明は、上記事情にかんがみ創案されたもの
である。 The present invention has been devised in view of the above circumstances.
問題点を解決するための手段
本発明者らは、遷移金属の遊離酸をセルロース
繊維をはじめ、尿素樹脂、メラミン樹脂、フエノ
ール樹脂等の有機化合物に付着させると変色濃度
の高いホトクロミツク現象が得られることを見い
だし本発明に至つたもので、タングステン酸、モ
リブデン酸及びバナジン酸より選ばれる遊離の遷
移金属酸のホトクロミツク物質を尿素系、メラミ
ン系、フエノール系又はポリビニルアルコール系
の樹脂の水溶液中に分散させ、この分散液で処理
したセルロース繊維よりなる繊維状物、あるいは
この分散液からフイルムを製造し、これを細片又
は糸状に切断した繊維状物よりなる製紙用繊維を
提供するものである。Means for Solving the Problems The present inventors have found that when a free acid of a transition metal is attached to an organic compound such as a cellulose fiber, a urea resin, a melamine resin, or a phenol resin, a photochromic phenomenon with a high density of discoloration can be obtained. This discovery led to the present invention, in which a photochromic substance of a free transition metal acid selected from tungstic acid, molybdic acid, and vanadate acid is dispersed in an aqueous solution of urea-based, melamine-based, phenol-based, or polyvinyl alcohol-based resin. The present invention provides a fibrous material made of cellulose fibers treated with this dispersion, or a fibrous material made by producing a film from this dispersion and cutting the film into strips or threads.
作 用
すなわち、本発明は各種の遷移金属元素を有す
る化合物、例えばタングステン酸ナトリウム、モ
リブデン酸ナトリウム及びバナジン酸ナトリウム
等を塩酸酸性又はイオン交換樹脂法によつて、遊
離酸としてのタングステン酸、モリブデン酸及び
バナジン酸とする。この遊離酸を植物性の晒パル
プに付着又は含浸させた後に、例えば尿素又はメ
ラミンをホルマリン液で高分子化反応を行い、遊
離酸を植物性の晒パルプに固着させたもので、こ
のものは不溶性のホトクロミツク繊維となる。ま
た、重合型樹脂又は繊維素系樹脂、例えばポリビ
ニルアルコール又はヒドロキシエチルセルロース
等の水溶液中に前記遊離酸を分散させ、ホトクロ
ミツクフイルムを形成させ、これを細片又は糸状
にしてホトクロミツク繊維とする。In other words, the present invention provides compounds containing various transition metal elements, such as sodium tungstate, sodium molybdate, and sodium vanadate, to tungstic acid and molybdic acid as free acids by acidifying with hydrochloric acid or using an ion exchange resin method. and vanadate. After attaching or impregnating this free acid to vegetable bleached pulp, for example, urea or melamine is subjected to a polymerization reaction with a formalin solution, and the free acid is fixed to the vegetable bleached pulp. It becomes an insoluble photochromic fiber. Alternatively, the free acid is dispersed in an aqueous solution of a polymeric resin or cellulose resin, such as polyvinyl alcohol or hydroxyethyl cellulose, to form a photochromic film, which is then shaped into strips or threads to form photochromic fibers.
実施例
以下に、本発明の実施例を示す。これらの実施
例では遷移金属酸としてタングステン酸、樹脂と
して尿素樹脂及びポリビニルアルコールとポリビ
ニルピロリドンを用いた例を示しているが、本発
明においては、遷移金属酸としてモリブデン酸も
しくはバナジン酸を用いても、また、樹脂とし
て、メラミン系やフエノール系樹脂を用いても、
これらの実施例とほぼ同様の操作で同様の効果を
得ることができる。Examples Examples of the present invention are shown below. These examples use tungstic acid as the transition metal acid and urea resin, polyvinyl alcohol, and polyvinylpyrrolidone as the resin, but in the present invention, molybdic acid or vanadate may also be used as the transition metal acid. Also, even if melamine or phenol resin is used as the resin,
Similar effects can be obtained by operations substantially similar to those of these embodiments.
実施例 1
市販のタングステン酸ナトリウム0.8g、尿素
6g、37%ホルマリン16gを水300gに室温状態でか
くはんしながら溶解し、溶解後晒パルプ1.2gを加
え、良くかくはんして繊維を分散させる。分散後
3.7塩酸6.1gをかくはんしながら徐々に滴下し、
水溶性の遊離タングステン酸を生成させながら3
時間含浸し、繊維の表面又は内部でメチロール化
と不溶化を進行させる。含浸後繊維をろ別し、水
洗及び乾燥することによつてホトクロミツク繊維
1.2gを得た。Example 1 Commercially available sodium tungstate 0.8g, urea
Dissolve 6 g, 16 g of 37% formalin in 300 g of water with stirring at room temperature. After dissolving, add 1.2 g of bleached pulp and stir well to disperse the fibers. After dispersion
3.7 Gradually drop 6.1g of hydrochloric acid while stirring,
3 while generating water-soluble free tungstic acid.
The fiber is impregnated for a period of time to progress methylolation and insolubilization on the surface or inside of the fiber. After impregnation, the fibers are filtered, washed with water, and dried to produce photochromic fibers.
Obtained 1.2g.
実施例 2
市販のタングステン酸ナトリウム1gを水100g
に溶解し、溶解後陽イオン交換樹脂(アンバーラ
イト製IR−120B)に通し、水溶性の遊離タング
ステン酸液を回収する。回収後直ちに室温状態で
かくはんしながら水200g、晒パルプ1.2g、尿素
6g、37%ホルマリン16gを加えて繊維を分散させ
ながら3時間含浸する。含浸後繊維をろ別し、水
洗及び乾燥することによつてホトクロミツク繊維
1.2gを得た。Example 2 1 g of commercially available sodium tungstate in 100 g of water
After dissolving, the solution is passed through a cation exchange resin (IR-120B manufactured by Amberlite) to recover a water-soluble free tungstic acid solution. Immediately after collection, add 200g of water, 1.2g of bleached pulp, and urea while stirring at room temperature.
Add 6 g and 16 g of 37% formalin and soak for 3 hours while dispersing the fibers. After impregnation, the fibers are filtered, washed with water, and dried to produce photochromic fibers.
Obtained 1.2g.
実施例 3
市販のタングステン酸ナトリウム5gを水95gに
溶解し、溶解後陽イオン交換樹脂(アンバーライ
ト製IR−120B)に通し、水溶性の遊離タングス
テン酸液を回収する。回収後遊離タングステン酸
液12gに直ちにポリビニルアルコール(日本合成
化学製NH−17)0.6g、ポリビニルピロリドン
(BASF社製K−90)2.4gを室温状態でかくはん
しながら均一に溶解させる。溶解後、この樹脂液
を平滑なガラス上に移し、静置してホトクロミツ
クフイルムを得た。これを繊維状又は細片にして
製紙用繊維とした。Example 3 5 g of commercially available sodium tungstate is dissolved in 95 g of water and passed through a cation exchange resin (IR-120B manufactured by Amberlite) to recover a water-soluble free tungstic acid solution. Immediately after recovery, 0.6 g of polyvinyl alcohol (NH-17 manufactured by Nippon Gosei Kagaku) and 2.4 g of polyvinyl pyrrolidone (K-90 manufactured by BASF) are uniformly dissolved in 12 g of the free tungstic acid solution while stirring at room temperature. After dissolving, this resin liquid was transferred onto a smooth glass and allowed to stand to obtain a photochromic film. This was made into fibers or pieces and used as paper-making fibers.
発明の効果
本発明によつて得られたホトクロミツク繊維
は、従来、真偽の識別又は特殊性を維持するため
の手段として用いられている公知の蛍光繊維、着
色繊維、水玉模様及びスレツド等の認識機能とは
異なる新たな標識物質とすることができ、これを
含有する用紙は、太陽光又は高圧水銀灯により光
照射すると青色に発色し、暗所に放置すれば元の
色に戻るので、特定の応用、例えば有価証券、秘
密文書その他機密性を有する用紙の製紙用原料と
して有用である。Effects of the Invention The photochromic fiber obtained by the present invention can recognize known fluorescent fibers, colored fibers, polka dot patterns, threads, etc., which have been conventionally used as a means for distinguishing authenticity or maintaining speciality. It can be used as a new labeling substance with a different function, and the paper containing this turns blue when exposed to sunlight or a high-pressure mercury lamp, and returns to its original color when left in a dark place. It is useful for applications such as paper manufacturing for securities, confidential documents, and other sensitive papers.
Claims (1)
酸より選ばれる遊離の遷移金属酸のホトクロミツ
ク物質を尿素系、メラミン系、フエノール系又は
ポリビニルアルコール系の樹脂の水溶液中に分散
させ、この分散液で処理したセルロース繊維より
なる繊維状物、あるいはこの分散液からフイルム
を製造し、これを細片又は糸状に切断した繊維状
物よりなる製紙用繊維。1 Cellulose fibers obtained by dispersing a photochromic substance of a free transition metal acid selected from tungstic acid, molybdic acid, and vanadate in an aqueous solution of a urea-based, melamine-based, phenol-based, or polyvinyl alcohol-based resin, and treated with this dispersion. A papermaking fiber consisting of a fibrous material made of a fibrous material, or a fibrous material obtained by producing a film from this dispersion and cutting the film into strips or threads.
Priority Applications (1)
Application Number | Priority Date | Filing Date | Title |
---|---|---|---|
JP60019304A JPS61179399A (en) | 1985-02-05 | 1985-02-05 | Papermaking fiber having photochromic substance adhered thereto |
Applications Claiming Priority (1)
Application Number | Priority Date | Filing Date | Title |
---|---|---|---|
JP60019304A JPS61179399A (en) | 1985-02-05 | 1985-02-05 | Papermaking fiber having photochromic substance adhered thereto |
Publications (2)
Publication Number | Publication Date |
---|---|
JPS61179399A JPS61179399A (en) | 1986-08-12 |
JPH0571717B2 true JPH0571717B2 (en) | 1993-10-07 |
Family
ID=11995675
Family Applications (1)
Application Number | Title | Priority Date | Filing Date |
---|---|---|---|
JP60019304A Granted JPS61179399A (en) | 1985-02-05 | 1985-02-05 | Papermaking fiber having photochromic substance adhered thereto |
Country Status (1)
Country | Link |
---|---|
JP (1) | JPS61179399A (en) |
Cited By (3)
Publication number | Priority date | Publication date | Assignee | Title |
---|---|---|---|---|
US8690975B2 (en) | 2007-02-27 | 2014-04-08 | Plasco Energy Group Inc. | Gasification system with processed feedstock/char conversion and gas reformulation |
US9109172B2 (en) | 2006-05-05 | 2015-08-18 | Plasco Energy Group Inc. | Low temperature gasification facility with a horizontally oriented gasifier |
US9321640B2 (en) | 2010-10-29 | 2016-04-26 | Plasco Energy Group Inc. | Gasification system with processed feedstock/char conversion and gas reformulation |
Families Citing this family (5)
Publication number | Priority date | Publication date | Assignee | Title |
---|---|---|---|---|
GB8802590D0 (en) * | 1988-02-05 | 1988-03-02 | Courtaulds Plc | Fibre |
JPH04202898A (en) * | 1990-11-22 | 1992-07-23 | Fukui Pref Gov | Chromic patterned paper and its production |
FR2669948B1 (en) * | 1990-11-29 | 1993-01-22 | Arjomari Europ | SECURITY DOCUMENT COMPRISING A SECURITY ELEMENT HAVING PHOTOCHROMIC PROPERTIES. |
JP4744477B2 (en) * | 2007-05-01 | 2011-08-10 | 興和株式会社 | Regeneration time indicator for light regenerating deodorant |
JP6954523B2 (en) * | 2017-02-10 | 2021-10-27 | 国立大学法人山口大学 | Composite film containing transition metal oxide and cellulose nanofibers and method for producing the same |
-
1985
- 1985-02-05 JP JP60019304A patent/JPS61179399A/en active Granted
Cited By (3)
Publication number | Priority date | Publication date | Assignee | Title |
---|---|---|---|---|
US9109172B2 (en) | 2006-05-05 | 2015-08-18 | Plasco Energy Group Inc. | Low temperature gasification facility with a horizontally oriented gasifier |
US8690975B2 (en) | 2007-02-27 | 2014-04-08 | Plasco Energy Group Inc. | Gasification system with processed feedstock/char conversion and gas reformulation |
US9321640B2 (en) | 2010-10-29 | 2016-04-26 | Plasco Energy Group Inc. | Gasification system with processed feedstock/char conversion and gas reformulation |
Also Published As
Publication number | Publication date |
---|---|
JPS61179399A (en) | 1986-08-12 |
Similar Documents
Publication | Publication Date | Title |
---|---|---|
DE3533378C2 (en) | Process for applying security features within a paper and its application | |
US3876496A (en) | Method and means for protecting documents | |
DE69927681T2 (en) | FLUORESCENT GRAINS, METHOD FOR THE PRODUCTION THEREOF AND THEIR USE IN FORGETHER-SAFE PAPERS | |
KR100524333B1 (en) | Ink containing a SERRS active sol | |
Feczkó et al. | Textiles screen‐printed with photochromic ethyl cellulose–spirooxazine composite nanoparticles | |
EP0169750A1 (en) | Luminescent security fibres; security documents and other materials containing these fibres | |
JPH0571717B2 (en) | ||
JP2010077436A (en) | Exudative ink for printing security document | |
CN101440591B (en) | Fluorescent fibre for anti-counterfeiting document and anti-counterfeiting file | |
KR101450614B1 (en) | Security Paper Having Security Element of Discoloration by Chemical and Method for Manufacturing the same | |
CN112143288A (en) | Hidden fluorescent anti-counterfeiting ink and preparation method and application thereof | |
US4618402A (en) | Safety means, paper and document against falsification by chemical agent | |
DE19923778A1 (en) | Cationic modified whitener dispersion for the paper industry | |
KR100517160B1 (en) | Two-color invisible fluorescent ink for anti-counterfeiting by using fluorescent material | |
GB2084930A (en) | Security paper | |
ATE284997T1 (en) | RECORDING PAPER WITH A COMBINATION OF MULTIPLE SECURITY FEATURES | |
EP0530059B1 (en) | System for the reversibel authentification of a security paper | |
RU2243307C1 (en) | Securities protected against forgery, method for manufacture and materials used in manufacture (modifications) | |
Jun‐Ling et al. | The dyeing of nylon with a microencapsulated disperse dye | |
JP3461447B2 (en) | Forgery prevention paper, forgery prevention printed matter, and mechanical detection method of forgery prevention means | |
FR2654446A1 (en) | Safety means, paper and document against falsification using a chemical agent and forgery | |
DE2301531A1 (en) | 4,4'-DIAMINOSTILBE-2,2'-DISULPHONIC ACID DERIVATIVES AND THEIR USES | |
JPS649957B2 (en) | ||
CN105463943B (en) | A kind of cheque paper and its manufacture method | |
JP2008248425A (en) | Method for improving fading characteristic of mechanical pulp |
Legal Events
Date | Code | Title | Description |
---|---|---|---|
LAPS | Cancellation because of no payment of annual fees |