JP2002088672A - Method for bleaching pulp - Google Patents
Method for bleaching pulpInfo
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- JP2002088672A JP2002088672A JP2000265522A JP2000265522A JP2002088672A JP 2002088672 A JP2002088672 A JP 2002088672A JP 2000265522 A JP2000265522 A JP 2000265522A JP 2000265522 A JP2000265522 A JP 2000265522A JP 2002088672 A JP2002088672 A JP 2002088672A
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- ultraviolet
- pulp
- bleaching
- oxidizing agent
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Abstract
Description
【０００１】[0001]
【発明の属する技術分野】本発明は、パルプの漂白方法
に関し、更に詳しくは酸化剤を用いるパルプ漂白法の改
良に関する。The present invention relates to a pulp bleaching method, and more particularly to an improvement in a pulp bleaching method using an oxidizing agent.
【０００２】[0002]
【従来の技術】木材中の純粋な繊維は、通常、無色であ
るが、木材等を加工することにより得られる粗パルプに
は種々の不純物が含まれるために着色している。これを
白色度の高い紙の原料とするためには、着色不純物を薬
剤などにより分解、又は無色化する漂白工程を必要とす
る。2. Description of the Related Art Pure fibers in wood are usually colorless, but crude pulp obtained by processing wood and the like is colored because of various impurities. In order to use this as a raw material for a paper having high whiteness, a bleaching step is required to decompose colored impurities with a chemical or the like or to make the colorless.
【０００３】従来、このような漂白薬剤としては、塩
素、次亜塩素酸塩、二酸化塩素等が用いられているが、
ハロゲン原子を含む薬剤は環境に対する負荷が大きく、
また人体に対する危険性も大きいので、操業安全性に問
題があり、また、これらの漂白過程は多くの場合に高温
で行われるので、大量のエネルギーを要する多消費型プ
ロセスであり、その為に多量の二酸化炭素の放出を伴う
という難点も包含している。Conventionally, chlorine, hypochlorite, chlorine dioxide and the like have been used as such bleaching agents.
Drugs containing halogen atoms have a large impact on the environment,
In addition, there is a large risk to the human body, so there is a problem in the safety of operation.Moreover, since these bleaching processes are often performed at high temperatures, they are multi-consuming processes requiring a large amount of energy, and therefore a large amount of It also has the disadvantage of involving the release of carbon dioxide.
【０００４】これらの問題点を解決するために、過酸化
水素等の酸化剤を用いる方法が報告されている。更に、
該過酸化水素を用いる方法において、通常の可視・紫外
光を照射する方法も提案されている（例えば、Koplik,
M.; Milichovsky, M. "Photochemical bleaching of pa
per webs", Cellul. Chem. Technol., 32, 349 (199
8)；Ruggiero, R.; Machado, A. E. H.; Da S. P. D.;G
relier, S.; Nourmamode,A.; Castellan, A. "Bleached
chemical pulp from Eucalyptus grandis woodproduce
d by peroxyformic acid pulping and photochemical b
leaching", Holzforschung, 52, 325 (1998)）。しか
し、これらの方法は、いずれの場合も従来のハロゲン系
薬剤漂白法と比べて十分な漂白効果が得られない、処理
時間が長い、高温処理を要する、などといった問題点を
かかえているのが現状である。[0004] In order to solve these problems, a method using an oxidizing agent such as hydrogen peroxide has been reported. Furthermore,
In the method using hydrogen peroxide, a method of irradiating ordinary visible / ultraviolet light has also been proposed (for example, Koplik,
M .; Milichovsky, M. "Photochemical bleaching of pa
per webs ", Cellul. Chem. Technol., 32, 349 (199
8); Ruggiero, R .; Machado, AEH; Da SPD; G
relier, S .; Nourmamode, A .; Castellan, A. "Bleached
chemical pulp from Eucalyptus grandis woodproduce
d by peroxyformic acid pulping and photochemical b
leaching ", Holzforschung, 52, 325 (1998)) However, these methods do not provide a sufficient bleaching effect as compared with the conventional halogen-based chemical bleaching method, have a long processing time, and have a high temperature treatment. Currently, there are problems such as the need for
【０００５】[0005]
【発明が解決しようとする課題】本発明は、このような
問題点を克服するためになされたものであって、高温及
び長時間の処理を必要とせず、また環境負荷が小さいと
共に操業安全性が高く、しかも二酸化炭素排出の削減が
可能で環境に優しいパルプの漂白方法を提供することを
目的とする。SUMMARY OF THE INVENTION The present invention has been made to overcome such problems, does not require high-temperature and long-time processing, has a small environmental load, and has a high operational safety. It is an object of the present invention to provide an environmentally-friendly pulp bleaching method which has a high pulp content and is capable of reducing carbon dioxide emission.
【０００６】[0006]
【課題を解決するための手段】本発明者らは、かかる従
来技術の難点を解消するために鋭意検討した結果、特定
の酸化剤と有機光化学的反応を組み合わせる方法が有効
であること見い出し、本発明をなすに至った。Means for Solving the Problems The present inventors have conducted intensive studies to solve the problems of the prior art, and as a result, have found that a method of combining a specific oxidizing agent and an organic photochemical reaction is effective. Invented the invention.
【０００７】すなわち本発明によれば、第一に、粗パル
プに、下記一般式（１）で示される酸化剤の存在下、紫
外・可視光を照射することを特徴とするパルプの漂白方
法が提供される。 ＲＯＯＲ’ （１） （Ｒは、アリール基、アルキルカルボニル基、アリール
カルボニル基、アルコキシカルボニル基、アリーロキシ
カルボニル基、ホルミル基又は水素を、Ｒ’は、アリー
ル基、アルキルカルボニル基、アリールカルボニル基、
アルコキシカルボニル基、アリーロキシカルボニル基又
はホルミル基を表す。） 第二に、第一の方法において、紫外・可視光が紫外・可
視レーザー光であることを特徴とするパルプの漂白方法
が提供される。That is, according to the present invention, firstly, there is provided a method for bleaching pulp, which comprises irradiating ultraviolet / visible light to crude pulp in the presence of an oxidizing agent represented by the following general formula (1). Provided. ROOR '(1) (R is an aryl group, an alkylcarbonyl group, an arylcarbonyl group, an alkoxycarbonyl group, an aryloxycarbonyl group, a formyl group or hydrogen; R' is an aryl group, an alkylcarbonyl group, an arylcarbonyl group,
Represents an alkoxycarbonyl group, an aryloxycarbonyl group or a formyl group. Secondly, there is provided a method for bleaching pulp according to the first method, wherein the ultraviolet / visible light is ultraviolet / visible laser light.
【０００８】すなわち、本発明方法は、パルプに含まれ
ている着色物質、たとえばリグニン由来の芳香環や多重
結合から成るπ電子共役系有機化合物が、紫外・可視光
照射により基底状態から励起状態への電子励起が起こ
り、その結果、より活性な性質を有する状態に転じ、そ
のことにより酸化剤との反応性が高まり該着色物質の分
解反応若しくは無色化反応が促進される現象、あるい
は、その逆に該紫外・可視光照射により酸化剤、又は酸
化剤／溶媒がより活性な物質に転じ、そのことにより着
色物質との反応性が向上し、該着色物質の分解若しくは
無色化反応が増大する現象を巧みに利用したものであ
る。[0008] That is, the method of the present invention provides a method for converting a coloring substance contained in pulp, for example, a π-electron conjugated organic compound composed of a lignin-derived aromatic ring or multiple bond, from a ground state to an excited state by irradiation with ultraviolet or visible light. Occurs, resulting in a state having more active properties, thereby increasing the reactivity with the oxidizing agent and promoting the decomposition reaction or the colorless reaction of the coloring substance, or vice versa. The phenomenon in which the oxidizing agent or the oxidizing agent / solvent is converted into a more active substance by the irradiation of ultraviolet or visible light, thereby increasing the reactivity with the coloring substance and increasing the decomposition or colorless reaction of the coloring substance. Is a skillful use of
【０００９】従来の、酸化剤と通常の紫外・可視光を用
いる漂白方法においては、過酸化水素の紫外・可視光照
射による光化学反応過程により生じたヒドロキシラジカ
ルが、該着色物質と反応して該着色物質の分解若しくは
無色化反応を起こすものと考えられるが、過酸化水素の
紫外・可視領域のモル吸光係数は通常の芳香族化合物や
共役系を有する有機化合物と比べて極端に小さいので、
光化学的に発生するヒドロキシラジカルの濃度は低いも
のでしかなく、その結果、ハロゲン系薬剤漂白法と比べ
て十分な漂白効果が得られないこと、処理時間が長いこ
と、高温処理を要すること、などといった問題点を包含
していた。In a conventional bleaching method using an oxidizing agent and ordinary ultraviolet / visible light, a hydroxyl radical generated by a photochemical reaction process by irradiation of ultraviolet / visible light with hydrogen peroxide reacts with the coloring substance to produce the hydroxyl radical. Although it is thought that the decomposition or colorless reaction of the coloring substance occurs, the molar extinction coefficient of hydrogen peroxide in the ultraviolet and visible regions is extremely small as compared with ordinary aromatic compounds and organic compounds having a conjugated system.
The concentration of photochemically generated hydroxyl radicals is only low, and as a result, sufficient bleaching effect cannot be obtained as compared with the halogen bleaching method, long processing time, high temperature processing, etc. The problem was included.
【００１０】本発明は、これらの問題点を、酸化剤とし
て、前記一般式（１）で示される特定な酸化剤を用いる
ことにより解決したものである。すなわち、これらの酸
化剤は、従来から用いられている過酸化水素と比べてそ
の紫外・可視領域のモル吸光係数が非常に大きいため
に、過酸化水素と比べて該着色物質の分解若しくは無色
化反応を起こすために必要な光化学的に発生するヒドロ
キシラジカル、或いはアルコキシラジカルの濃度を高く
することが可能となる為に、これらの有機過酸化物を用
いると着色物質との反応性が向上し、該着色物質の分解
若しくは無色化反応を著しく高めることができる。本発
明で用いる酸化剤は前記一般式（１）で示される。一般
式（１）において、アリール基としては、フェニル基、
ナフチル基、ビフェニル基、アントリル基、それらの置
換体、等が、アルキルカルボニル基としては、アセチル
基、エチルカルボニル基、プロピオニルカルボニル基、
それらの置換体、等が、アリールカルボニル基として
は、ベンゾイル基、ナフチルカルボニル基、ビフェニル
カルボニル基、それらの置換体、等が、アルコキシカル
ボニル基としては、メトキシカルボニル基、エトキシカ
ルボニル基、それらの置換体、等が、アリーロキシカル
ボニル基としては、フェノキシカルボニル基、ナフトキ
シカルボニル基、ビフェニロキシカルボニル基、それら
の置換体、等が挙げられる。これらの酸化剤の具体例と
しては、例えば、過安息香酸及びその誘導体、過酢酸、
過蟻酸等の過酸、それら過酸のエステル類、過炭酸及び
そのエステル類、等の有機過酸化物が挙げられる。本発
明で好ましく使用される酸化剤は、過安息香酸及びその
誘導体である。The present invention has solved these problems by using the specific oxidizing agent represented by the general formula (1) as the oxidizing agent. That is, these oxidizing agents have a very large molar extinction coefficient in the ultraviolet and visible regions as compared with conventionally used hydrogen peroxide, so that the coloring substance is decomposed or colorless compared with hydrogen peroxide. In order to increase the concentration of photochemically generated hydroxyl radicals or alkoxy radicals required to cause a reaction, the use of these organic peroxides improves the reactivity with coloring substances, The decomposition or colorless reaction of the coloring substance can be significantly increased. The oxidizing agent used in the present invention is represented by the general formula (1). In the general formula (1), the aryl group includes a phenyl group,
Naphthyl group, biphenyl group, anthryl group, their substituents, etc., as alkylcarbonyl group, acetyl group, ethylcarbonyl group, propionylcarbonyl group,
The substituents, etc., are arylcarbonyl groups, such as benzoyl group, naphthylcarbonyl group, biphenylcarbonyl group, their substitutions, etc., and the alkoxycarbonyl groups are methoxycarbonyl group, ethoxycarbonyl group, their substitution. Examples of the aryloxycarbonyl group include a phenoxycarbonyl group, a naphthoxycarbonyl group, a biphenyloxycarbonyl group, a substituted product thereof, and the like. Specific examples of these oxidizing agents include, for example, perbenzoic acid and its derivatives, peracetic acid,
Organic peroxides such as peracids such as formic acid, esters of those peracids, percarbonates and their esters, and the like. The oxidizing agents preferably used in the present invention are perbenzoic acid and its derivatives.
【００１１】また、本発明において、紫外・可視光とし
て、紫外・可視レーザー光を選定すると、該着色物質の
分解若しくは無色化反応を行うために必要なヒドロキシ
ラジカルの濃度を高くすることが可能となり、通常の紫
外・可視光を照射した場合に比べ該反応が著しく高速化
されることから、その漂白時間に要する時間や漂白温度
の低減化が達成でき、更には、環境負荷が小さいと共に
操業安全性が高く、しかも二酸化炭素排出の削減が可能
で環境に優しいといった顕著な作用効果を呈する。更
に、通常の紫外・可視光照射による光化学的ヒドロキシ
ラジカル生成は一光子過程のみによるものであるのに対
し、レーザー光を用いると、一光子過程の他に多光子過
程によるヒドロキシラジカル生成の可能性も高くなる為
に、更に漂白時間に要する時間や漂白温度の低減化や、
環境負荷が小さいと共に操業安全性が高く、しかも二酸
化炭素排出の削減が可能で環境に優しいといった顕著な
作用効果が期待できる。In the present invention, when ultraviolet / visible laser light is selected as the ultraviolet / visible light, it becomes possible to increase the concentration of the hydroxyl radical necessary for performing the decomposition or colorless reaction of the coloring substance. Since the reaction is remarkably accelerated as compared with the case of irradiation with ordinary ultraviolet / visible light, the time required for the bleaching time and the bleaching temperature can be reduced. It has a remarkable action and effect, such as high performance, and capable of reducing carbon dioxide emissions and being environmentally friendly. Furthermore, while photochemical hydroxyl radical generation by ordinary ultraviolet / visible light irradiation is based on only one-photon process, the possibility of hydroxyl radical generation by multi-photon process in addition to one-photon process when laser light is used To reduce the bleaching time and the bleaching temperature,
Significant effects such as low environmental load, high operational safety, and reduction of carbon dioxide emission and environmental friendliness can be expected.
【００１２】本発明の漂白の対象となるパルプには、木
材より得られる機械パルプ、半化学パルプ、化学パルプ
の他、回収古紙より得られる古紙パルプ、藁や亜麻等か
ら得られる非木材パルプ等が包含される。The pulp to be bleached according to the present invention includes mechanical pulp, semi-chemical pulp, and chemical pulp obtained from wood, used paper pulp obtained from recovered waste paper, non-wood pulp obtained from straw, flax, and the like. Is included.
【００１３】本発明における前記酸化剤は単独で用いて
も良いが、紫外・可視光を透過する溶媒に分散若しくは
溶解させて使用することが望ましい。このような溶媒と
しては、水、アルコール類、鎖状または環状のアルカン
類、エーテル類等の単独溶媒あるいはこれらの混合溶媒
が挙げられるが、酸化剤を溶解又は分散する溶媒、或い
は混合溶媒であればその種類に限定されない。酸化剤の
使用量は特に制限はないが、好ましくは溶媒に対する酸
化剤の飽和濃度以下であれば良く、より好ましくは０．
１〜２０重量％とするのが適当である。The oxidizing agent in the present invention may be used alone, but it is preferable to use it after dispersing or dissolving it in a solvent that transmits ultraviolet and visible light. Examples of such a solvent include a single solvent such as water, alcohols, chain or cyclic alkanes, and ethers or a mixed solvent thereof, and a solvent that dissolves or disperses an oxidizing agent or a mixed solvent. It is not limited to that type. The amount of the oxidizing agent is not particularly limited, but is preferably not more than the saturation concentration of the oxidizing agent with respect to the solvent, and more preferably is not more than 0.1%.
Suitably, it is 1 to 20% by weight.
【００１４】本発明における紫外・可視光照射における
光照射波長に特に制限は無いが、波長が１８０〜８００
ｎｍ、好ましくは１８０〜４００ｎｍ程度のものを用い
ることが望ましい。また、本発明における紫外・可視光
照射における光照射強度にも特に制限は無いが、連続光
は０．１ｍＷ〜１０ｋＷ／ｃｍ２、パルス光では０．１
ｍＪ／パルス・ｃｍ２〜１ｋＪ／パルス・ｃｍ２が適し
ている。紫外・可視レーザー光源としては特に制限はな
く、またレーザー光はパルス光でも連続照射光でもよい
が、エキシマレーザー（ＡｒＦエキシマレーザー、Ｋｒ
Ｆエキシマレーザー、ＸｅＣｌエキシマレーザー、Ｘｅ
Ｆエキシマレーザー等）、アルゴンイオンレーザー、ク
リプトンイオンレーザー、ＹＡＧレーザーの第２、及び
第３高調波等が好ましく使用される。There is no particular limitation on the light irradiation wavelength in the ultraviolet / visible light irradiation in the present invention.
nm, preferably about 180 to 400 nm. In addition, although the light irradiation intensity in the ultraviolet / visible light irradiation in the present invention is not particularly limited, continuous light is 0.1 mW to 10 kW / cm 2 , and pulsed light is 0.1 mW to 10 kW / cm 2 .
mJ / pulse · cm 2 to 1 kJ / pulse · cm 2 is suitable. There is no particular limitation on the ultraviolet / visible laser light source. The laser light may be pulsed light or continuous irradiation light, and may be an excimer laser (ArF excimer laser, Kr
F excimer laser, XeCl excimer laser, Xe
F excimer laser, etc.), the second and third harmonics of an argon ion laser, a krypton ion laser, and a YAG laser are preferably used.
【００１５】光照射温度にも特に制限は無く、用いた溶
媒の凝固点以上、沸点以下であればよいが、好ましくは
−８０℃〜１００℃、より好ましくは０〜４０℃であ
る。光照射時間は、原料パルプの着色度、酸化剤あるい
は溶媒の種類やその濃度更には、照射紫外・可視光の種
類や光強度等を考慮することにより適宜定められるが、
通常、１秒〜３０分もあれば充分である。The light irradiation temperature is not particularly limited, and may be any temperature from the freezing point to the boiling point of the solvent used, preferably from -80 ° C to 100 ° C, more preferably from 0 to 40 ° C. The light irradiation time is appropriately determined by considering the degree of coloring of the raw material pulp, the type and concentration of the oxidizing agent or the solvent, and the type and light intensity of the irradiation ultraviolet and visible light.
Usually, 1 second to 30 minutes is sufficient.
【００１６】本発明方法は、粗パルプと酸化剤を接触さ
せた所に紫外・可視光を照射すればよく、特にその実施
の態様に制限はない。好ましい実施の態様としては、例
えば、原料パルプを、酸化剤を含む紫外・可視光を透過
する溶媒に、分散、溶解した後、紫外・可視光を照射す
る方法、原料パルプをシート状、或いは薄片状に成型し
た後、これを上記の酸化剤を含む溶媒に含浸、あるいは
含浸させた後、紫外・可視光を照射する方法等が挙げら
れる。In the method of the present invention, ultraviolet and visible light may be applied to the place where the crude pulp is brought into contact with the oxidizing agent, and there is no particular limitation on the embodiment. As a preferred embodiment, for example, a method of irradiating ultraviolet and visible light after dispersing and dissolving the raw pulp in a solvent that transmits ultraviolet and visible light containing an oxidizing agent, and irradiating the raw pulp with a sheet or flake And then impregnating it with a solvent containing the above-mentioned oxidizing agent, and then irradiating with ultraviolet / visible light.
【００１７】[0017]
【実施例】次に実施例に基づき、本発明を更に詳細に説
明する。Next, the present invention will be described in more detail with reference to examples.
【００１８】実施例１ 粗パルプ約０．１１ｇ（乾燥重量）を３０ｍｌの６％ｍ
−クロロ過安息香酸エタノール溶液に分散させ、この分
散液に４００ｍＪ／パルス、５Ｈｚのクリプトンフッ素
エキシマレーザーを１分間照射した。この分散液を濾過
し、引き続き濾過物をエタノールと水で洗浄した。洗浄
後の濾過物を直径約２．５ｃｍの円盤状にし、乾燥後、
該パルプの白色度（ＪＩＳ Ｚ ８７１５）を拡散反射
装置の付いた紫外可視分光光度計により測定したとこ
ろ、−２６であった。Example 1 About 0.11 g (dry weight) of crude pulp was mixed with 30 ml of 6% m.
-Dispersed in an ethanol solution of chloroperbenzoic acid, and this dispersion was irradiated with a 400 mJ / pulse, 5 Hz krypton fluorine excimer laser for 1 minute. The dispersion was filtered and the filtrate was washed with ethanol and water. The filtered material after washing is made into a disk shape having a diameter of about 2.5 cm, and after drying,
The whiteness (JIS Z 8715) of the pulp measured by an ultraviolet-visible spectrophotometer equipped with a diffuse reflection device was -26.
【００１９】実施例２ 実施例１において、４００ｍＪ／パルス、５Ｈｚのクリ
プトンフッ素エキシマレーザーに代えて、Ｔｏｓｈｉｂ
ａ ＵＶ−２５フィルターを装着した５００Ｗのキセノ
ンランプを１分間照射した以外は実施例１と同様の操作
を行った。漂白後のパルプの白色度（ＪＩＳ Ｚ ８７
１５）は、−３５であった。Example 2 In Example 1, Toshib was replaced with a 400 mJ / pulse, 5 Hz krypton fluorine excimer laser.
a The same operation as in Example 1 was performed except that a 500 W xenon lamp equipped with a UV-25 filter was irradiated for 1 minute. Whiteness of pulp after bleaching (JIS Z 87
15) was -35.
【００２０】比較例１ 粗パルプ約０．１１ｇ（乾燥重量）を３０ｍｌの水に分
散させ、この分散液を濾過した後、濾過物を直径約２．
５ｃｍの円盤状にし、乾燥後、該パルプの白色度（ＪＩ
Ｓ Ｚ ８７１５）を拡散反射装置の付いた紫外可視分
光光度計により測定したところ、−５５であった。Comparative Example 1 About 0.11 g (dry weight) of crude pulp was dispersed in 30 ml of water, and the dispersion was filtered.
After making into a 5 cm disc shape and drying, the pulp whiteness (JI
S Z 8715) was -55 as measured by an ultraviolet-visible spectrophotometer equipped with a diffuse reflection device.
【００２１】比較例２ 粗パルプ約０．１１ｇ（乾燥重量）粗パルプ約０．１１
ｇ（乾燥重量）を３０ｍｌの６％過酸化水素水溶液に分
散させ、この分散液にＴｏｓｈｉｂａ ＵＶ−２５フィ
ルターを装着した５００Ｗのキセノンランプを１分間照
射した。この分散液を濾過し、引き続き濾過物を水で洗
浄した。洗浄後の濾過物を直径約２．５ｃｍの円盤状に
し、乾燥後、該パルプの白色度（ＪＩＳ Ｚ ８７１
５）を拡散反射装置の付いた紫外可視分光光度計により
測定したところ、−４０であった。Comparative Example 2 Crude pulp: about 0.11 g (dry weight) Crude pulp: about 0.11
g (dry weight) was dispersed in 30 ml of a 6% aqueous hydrogen peroxide solution, and this dispersion was irradiated with a 500 W xenon lamp equipped with a Toshiba UV-25 filter for 1 minute. The dispersion was filtered and the filtrate was subsequently washed with water. After washing, the filtered material was formed into a disc having a diameter of about 2.5 cm, dried, and then the whiteness of the pulp (JIS Z 871)
5) was measured with an ultraviolet-visible spectrophotometer equipped with a diffuse reflection device, and found to be -40.
【００２２】[0022]
【発明の効果】従来の、酸化剤と通常の紫外・可視光を
用いる漂白方法は、過酸化水素の紫外可視領域のモル吸
光係数が通常の芳香族化合物や共役系を有する有機化合
物と比べて極端に小さいので、光化学的に発生するヒド
ロキシラジカルの濃度は低いものでしかないことから、
ハロゲン系薬剤漂白法と比べて十分な漂白効果が得られ
ない、処理時間が長い、高温処理を要する、などといっ
た問題点を包含していたが、本発明においては、酸化剤
として、前記一般式（１）で示される特有な酸化剤を用
いたことから、該着色物質の分解若しくは無色化反応を
行うために必要なヒドロキシラジカルの濃度を高くする
ことが可能となるため、上記着色物質の分解反応や無色
化反応が促進され、従来の過酸化水素と光照射を利用し
た場合に比べその漂白時間に要する時間や漂白温度の低
減化が達成できる。また、本発明は、更には、環境負荷
が小さいと共に操業安全性が高く、しかも二酸化炭素排
出の削減が可能で環境に優しいといった顕著な作用効果
を呈する。According to the conventional bleaching method using an oxidizing agent and ordinary ultraviolet / visible light, the molar extinction coefficient of hydrogen peroxide in the ultraviolet / visible region is lower than that of ordinary aromatic compounds or organic compounds having a conjugated system. Since it is extremely small, the concentration of photochemically generated hydroxyl radical is only low,
Including a problem that a sufficient bleaching effect cannot be obtained as compared with the halogen bleaching method, a long processing time, a high-temperature treatment is required, and the like, but in the present invention, the oxidizing agent represented by the general formula Since the specific oxidizing agent shown in (1) is used, it becomes possible to increase the concentration of the hydroxy radical necessary for performing the decomposition or the colorless reaction of the coloring substance. The reaction and the colorless reaction are accelerated, and the time required for the bleaching time and the bleaching temperature can be reduced as compared with the case where conventional hydrogen peroxide and light irradiation are used. Further, the present invention has a remarkable effect that the environmental load is small, the operation safety is high, the carbon dioxide emission can be reduced, and the environment is friendly.
Claims (2)
酸化剤の存在下、紫外・可視光を照射することを特徴と
するパルプの漂白方法。 ＲＯＯＲ’ （１） （Ｒは、アリール基、アルキルカルボニル基、アリール
カルボニル基、アルコキシカルボニル基、アリーロキシ
カルボニル基、ホルミル基又は水素を、Ｒ’は、アリー
ル基、アルキルカルボニル基、アリールカルボニル基、
アルコキシカルボニル基、アリーロキシカルボニル基又
はホルミル基を表す。）1. A method for bleaching pulp, comprising irradiating a crude pulp with ultraviolet / visible light in the presence of an oxidizing agent represented by the following general formula (1). ROOR '(1) (R is an aryl group, an alkylcarbonyl group, an arylcarbonyl group, an alkoxycarbonyl group, an aryloxycarbonyl group, a formyl group or hydrogen; R' is an aryl group, an alkylcarbonyl group, an arylcarbonyl group,
Represents an alkoxycarbonyl group, an aryloxycarbonyl group or a formyl group. )
ることを特徴とする請求項１に記載の方法。2. The method according to claim 1, wherein the ultraviolet / visible light is ultraviolet / visible laser light.
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|---|---|---|---|
| JP2000265522A JP3368336B2 (en) | 2000-06-20 | 2000-09-01 | Pulp bleaching method |
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|---|---|---|---|
| JP2000183859 | 2000-06-20 | ||
| JP2000-183859 | 2000-06-20 | ||
| JP2000265522A JP3368336B2 (en) | 2000-06-20 | 2000-09-01 | Pulp bleaching method |
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|---|---|
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Cited By (6)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| JP2002235293A (en) * | 2001-02-06 | 2002-08-23 | National Institute Of Advanced Industrial & Technology | Method for bleaching cellulose derivative |
| WO2004042139A1 (en) * | 2002-11-07 | 2004-05-21 | Nippon Paper Industries Co., Ltd. | Method for improving the discoloration resistance of pulp and pulp improved in discoloration resistance |
| WO2005001198A1 (en) * | 2003-06-30 | 2005-01-06 | Nippon Paper Industries Co., Ltd. | Printing paper |
| WO2005121442A1 (en) * | 2004-06-08 | 2005-12-22 | Nippon Paper Industries Co., Ltd. | Method for bleaching pulp |
| JP2005350778A (en) * | 2004-06-08 | 2005-12-22 | Nippon Paper Industries Co Ltd | Method for bleaching pulp |
| CN100338303C (en) * | 2003-12-20 | 2007-09-19 | 广西大学 | Photochemical paper pulp bleaching method and device |
-
2000
- 2000-09-01 JP JP2000265522A patent/JP3368336B2/en not_active Expired - Lifetime
Cited By (7)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| JP2002235293A (en) * | 2001-02-06 | 2002-08-23 | National Institute Of Advanced Industrial & Technology | Method for bleaching cellulose derivative |
| WO2004042139A1 (en) * | 2002-11-07 | 2004-05-21 | Nippon Paper Industries Co., Ltd. | Method for improving the discoloration resistance of pulp and pulp improved in discoloration resistance |
| WO2005001198A1 (en) * | 2003-06-30 | 2005-01-06 | Nippon Paper Industries Co., Ltd. | Printing paper |
| CN100338303C (en) * | 2003-12-20 | 2007-09-19 | 广西大学 | Photochemical paper pulp bleaching method and device |
| WO2005121442A1 (en) * | 2004-06-08 | 2005-12-22 | Nippon Paper Industries Co., Ltd. | Method for bleaching pulp |
| JP2005350778A (en) * | 2004-06-08 | 2005-12-22 | Nippon Paper Industries Co Ltd | Method for bleaching pulp |
| JP4603298B2 (en) * | 2004-06-08 | 2010-12-22 | 日本製紙株式会社 | Pulp bleaching method |
Also Published As
| Publication number | Publication date |
|---|---|
| JP3368336B2 (en) | 2003-01-20 |
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