WO2005121442A1 - Method for bleaching pulp - Google Patents
Method for bleaching pulp Download PDFInfo
- Publication number
- WO2005121442A1 WO2005121442A1 PCT/JP2005/010521 JP2005010521W WO2005121442A1 WO 2005121442 A1 WO2005121442 A1 WO 2005121442A1 JP 2005010521 W JP2005010521 W JP 2005010521W WO 2005121442 A1 WO2005121442 A1 WO 2005121442A1
- Authority
- WO
- WIPO (PCT)
- Prior art keywords
- pulp
- bleaching
- light
- treatment
- whiteness
- Prior art date
Links
- 238000004061 bleaching Methods 0.000 title claims abstract description 214
- 238000000034 method Methods 0.000 title claims abstract description 117
- 238000010306 acid treatment Methods 0.000 claims abstract description 55
- 239000002253 acid Substances 0.000 claims abstract description 45
- 229920001131 Pulp (paper) Polymers 0.000 claims abstract description 42
- 238000012360 testing method Methods 0.000 claims abstract description 20
- 230000001678 irradiating effect Effects 0.000 claims abstract description 12
- 239000003638 chemical reducing agent Substances 0.000 claims abstract description 9
- 150000002894 organic compounds Chemical class 0.000 claims abstract description 6
- 150000002978 peroxides Chemical class 0.000 claims abstract description 6
- 238000002845 discoloration Methods 0.000 claims abstract description 5
- 150000001875 compounds Chemical class 0.000 claims abstract description 4
- 238000011282 treatment Methods 0.000 claims description 115
- CBENFWSGALASAD-UHFFFAOYSA-N Ozone Chemical compound [O-][O+]=O CBENFWSGALASAD-UHFFFAOYSA-N 0.000 claims description 97
- 229910052760 oxygen Inorganic materials 0.000 claims description 51
- 239000001301 oxygen Substances 0.000 claims description 51
- QVGXLLKOCUKJST-UHFFFAOYSA-N atomic oxygen Chemical compound [O] QVGXLLKOCUKJST-UHFFFAOYSA-N 0.000 claims description 50
- 238000009897 hydrogen peroxide bleaching Methods 0.000 claims description 41
- 239000013055 pulp slurry Substances 0.000 claims description 32
- 238000005562 fading Methods 0.000 claims description 30
- 239000007789 gas Substances 0.000 claims description 24
- 238000012545 processing Methods 0.000 claims description 20
- 230000002378 acidificating effect Effects 0.000 claims description 16
- 238000004076 pulp bleaching Methods 0.000 claims description 11
- 230000007423 decrease Effects 0.000 claims description 10
- 238000004519 manufacturing process Methods 0.000 claims description 10
- 229910052724 xenon Inorganic materials 0.000 claims description 10
- FHNFHKCVQCLJFQ-UHFFFAOYSA-N xenon atom Chemical compound [Xe] FHNFHKCVQCLJFQ-UHFFFAOYSA-N 0.000 claims description 10
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- 230000009467 reduction Effects 0.000 claims description 5
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- 238000010998 test method Methods 0.000 claims description 4
- 239000000126 substance Substances 0.000 abstract description 31
- 239000000460 chlorine Substances 0.000 abstract description 23
- 229910052801 chlorine Inorganic materials 0.000 abstract description 23
- ZAMOUSCENKQFHK-UHFFFAOYSA-N Chlorine atom Chemical compound [Cl] ZAMOUSCENKQFHK-UHFFFAOYSA-N 0.000 abstract description 22
- 238000005516 engineering process Methods 0.000 abstract description 7
- 230000003247 decreasing effect Effects 0.000 abstract 1
- 238000006243 chemical reaction Methods 0.000 description 81
- 239000000123 paper Substances 0.000 description 52
- QAOWNCQODCNURD-UHFFFAOYSA-N Sulfuric acid Chemical compound OS(O)(=O)=O QAOWNCQODCNURD-UHFFFAOYSA-N 0.000 description 34
- HEMHJVSKTPXQMS-UHFFFAOYSA-M Sodium hydroxide Chemical compound [OH-].[Na+] HEMHJVSKTPXQMS-UHFFFAOYSA-M 0.000 description 33
- MHAJPDPJQMAIIY-UHFFFAOYSA-N Hydrogen peroxide Chemical compound OO MHAJPDPJQMAIIY-UHFFFAOYSA-N 0.000 description 30
- OSVXSBDYLRYLIG-UHFFFAOYSA-N dioxidochlorine(.) Chemical compound O=Cl=O OSVXSBDYLRYLIG-UHFFFAOYSA-N 0.000 description 30
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- OSWFIVFLDKOXQC-UHFFFAOYSA-N 4-(3-methoxyphenyl)aniline Chemical compound COC1=CC=CC(C=2C=CC(N)=CC=2)=C1 OSWFIVFLDKOXQC-UHFFFAOYSA-N 0.000 description 2
- OKTJSMMVPCPJKN-UHFFFAOYSA-N Carbon Chemical compound [C] OKTJSMMVPCPJKN-UHFFFAOYSA-N 0.000 description 2
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- 241000196324 Embryophyta Species 0.000 description 2
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- YAXWOADCWUUUNX-UHFFFAOYSA-N 1,2,2,3-tetramethylpiperidine Chemical compound CC1CCCN(C)C1(C)C YAXWOADCWUUUNX-UHFFFAOYSA-N 0.000 description 1
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Classifications
-
- D—TEXTILES; PAPER
- D21—PAPER-MAKING; PRODUCTION OF CELLULOSE
- D21C—PRODUCTION OF CELLULOSE BY REMOVING NON-CELLULOSE SUBSTANCES FROM CELLULOSE-CONTAINING MATERIALS; REGENERATION OF PULPING LIQUORS; APPARATUS THEREFOR
- D21C9/00—After-treatment of cellulose pulp, e.g. of wood pulp, or cotton linters ; Treatment of dilute or dewatered pulp or process improvement taking place after obtaining the raw cellulosic material and not provided for elsewhere
- D21C9/10—Bleaching ; Apparatus therefor
- D21C9/1005—Pretreatment of the pulp, e.g. degassing the pulp
-
- 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
- D21C9/1084—Bleaching ; Apparatus therefor with reducing compounds
-
- 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
Definitions
- the present invention provides a method for bleaching pulp, which comprises irradiating pulp washed after acid treatment with ultraviolet light and Z or visible light under alkaline conditions. And / or a bleaching method characterized by accelerating the bleaching of pulp by performing a treatment combining irradiation treatment with visible light and ozone addition, and a chemical method capable of obtaining a chemical pulp having a high degree of whiteness.
- Pulp bleaching method (the above is referred to as the first invention)
- a new high-brightness chemical pulp and paper containing the same (referred to as the second invention).
- a bleaching method has been disclosed in which a bleaching method is carried out, or a bleaching method in which a digested chemical pulp is subjected to an acid treatment and then delignification with a peracid product and pressurized oxygen in an alkaline medium (for example, , Patent Document 1, Patent Document 2).
- the digested chemical pulp is subjected to high-temperature and high-pressure oxygen bleaching, followed by acid treatment or chelating agent treatment, and then peroxide or hydrogen peroxide in an alkaline medium.
- a bleaching method for delignification and bleaching using oxygen and oxygen is disclosed (for example, Patent Document 3).
- a suspension of cellulose pulp produced by the sulfate or alkali method is heated and treated at about 85-150 ° C and about pH 2-5, so that at least about 50% of the hexeneduronic acid in the cellulose pulp is obtained.
- a technique has been disclosed for removing pulp and reducing the pulp number of pulp by 2 to 9 units (see Patent Document 4).
- a technique of irradiating ultraviolet light in hydrogen peroxide bleaching of unbleached kraft pulp for example, see Non-Patent Document 1 or Patent Document 5
- a technique of irradiating ultraviolet light to oxygen bleaching of kraft pulp is disclosed.
- a technique of irradiating ultraviolet light in the presence of a peroxide as a pretreatment for accelerating the bleaching of alkaline hydrogen peroxide is disclosed.
- Patent Document 7 ultraviolet light or visible light or (Patent Document 7)
- UV or visible light or a combination of these in the presence of an organic peroxide represented by ROOR 'as an oxidizing agent (Patent Reference 8) is disclosed.
- Patent Document 1 Japanese Patent No. 2895977
- Patent Document 2 JP-A-6-101186
- Patent Document 3 JP-A-6-158573
- Patent Document 4 Japanese Translation of PCT International Publication No. 10-508346
- Patent Document 5 JP-A-2002-88673
- Patent Document 6 JP-A-6-128890
- Patent Document 7 JP-A-2002-88671
- Patent Document 8 JP-A-2002-88672
- Patent Document 9 Japanese Patent Application Laid-Open No. 2004-97992
- Non-Patent Document 1 B. Marccia, et al. J34 to J39, JOURNAL OF PULP AND PAPER SCIEN CE: Vol. L7, No. 2, March 1991
- Non-Patent Document 2 J. Abbot, et al. Pl98-202, Appita Vol. 46, No. 3, May 1993
- the background art of the second invention described below is as follows.
- High whiteness is required for paper products using chemical pulp as a main raw material, particularly for information recording paper such as ink-jet paper and thermal transfer recording paper, and for photographic paper support.
- unbleached kraft panolebs remain in unbleached pulp by multi-stage bleaching with chemicals such as chlorine, hypochlorite, chlorine dioxide, oxygen, hydrogen peroxide, ozone, etc. It removes coloring substances derived from lignin and polysaccharides.
- Chlorine gas The pulp obtained by the chlorine bleaching method and the ECF bleaching method with chlorine dioxide, which is more environmentally friendly in that the production of organic chlorine compounds is reduced, usually has an ISO whiteness of 82 to 86%.
- High brightness pulp that has been bleached to an unusually high level of whiteness will enhance cooking and / or bleaching conditions, or use readily digestible and bleaching tree species with low phenolic extractables. It is generally manufactured by the method described above.
- Conventional techniques for producing high brightness pulp include, for example, bleaching a pulp bleached by a sequence including at least one chlorine-based bleaching step, treating the pulp with xylanases, A method for producing high brightness pulp characterized by bleaching in a bleaching sequence of a chlorate stage and a chlorine dioxide stage has been disclosed (see Patent Document 10).
- the chlorine dioxide bleaching is characterized in that the step of the step is carried out at a high temperature of 91 ° C or higher and lower than 100 ° C with a chlorine dioxide addition rate of 1 to 3% by weight (based on absolute dry pulp). It has been disclosed (see Patent Document 11).
- the bleaching sequence is oxygen bleaching, ozone bleaching, alkali extraction, hydrogen peroxide bleaching, hydrogen peroxide bleaching, hydrogen peroxide bleaching, chlorine dioxide bleaching, and the ozone bleaching step uses 0.1 to 1.0% by weight of ozone based on absolutely dry pulp.
- a support base paper for photographic printing paper characterized in that it is a chemical pulp bleached (see Patent Document 12).
- unbleached kraft pulp with a kappa monovalent of 23 or less is bleached with oxygen at a delignification degree of 40% or more, and then bleached with ozone at a pulp concentration of 25% or more.
- Patent Document 10 JP-A-6-101185
- Patent Document 11 JP-A-9-1509509
- Patent Document 12 JP-A-2002-62622
- Patent Document 13 JP-A-2003-41494
- the object of the first invention is to further develop the pulp acid treatment or light irradiation technique as described above, reduce chlorine-based chemicals, and achieve more efficient bleaching methods than conventional bleaching methods.
- the aim is to develop a TCF bleaching method that significantly shortens the light irradiation time and achieves a final ISO brightness of 84% or more.
- An object of the second invention is to provide a pulp excellent in power and overcoming the disadvantages of the related art, which has a low environmental load and has fading, excellent high whiteness pulp, and paper containing the pulp. It is in. Means for solving the problem
- the present inventors have conducted intensive studies in order to solve the disadvantages of the above-mentioned conventional technology, and as a result, furthermore, the bleached pulp is further subjected to an ultraviolet light treatment. As a result, the present inventors have found that it is possible to produce a pulp having a high degree of whiteness, no fading, and a high paper strength, and completed the second invention. That is, (2) The invention has an ISO whiteness of 88% or more and the following fading test:
- Hand-made paper was prepared in accordance with QIS P 8222, and was prepared according to J. TAPPI No. 21 Paper and paperboard-Discoloration test method B method (method using a xenon arc lamp type light resistance tester).
- FIG. 1 is a diagram showing an example of a system using the irradiation reaction device according to the present invention.
- FIG. 2 is a view showing an internal irradiation type irradiation reaction apparatus used in the present invention.
- FIG. 3 is a view showing an internal irradiation type irradiation reaction apparatus used in Examples of the present invention.
- FIG. 4 is a graph showing the relationship between treatment pH and whiteness in light irradiation treatment using L-wood pulp.
- FIG. 5 is a view showing a relationship between light irradiation time and whiteness in light irradiation treatment using L-material pulp.
- FIG. 6 is a graph showing the relationship between treatment pH and whiteness in light irradiation treatment using N-material pulp.
- FIG. 7 is an example of an ultraviolet light bleaching experiment apparatus.
- the pulp targeted in 1 and 2 of the first invention is pulp washed after acid treatment.
- it is applied to kraft pulp (KP) and is suitable not only for unbleached KP, but also for oxygen delignification KP, ozon bleaching, etc.
- the pulp to be subjected to the bleaching method of the third aspect of the present invention is a chemical pulp which has been subjected to a craft digestion and subjected to an oxygen delignification treatment.
- the pulp raw material used in the first invention and the second invention (i-Danigaku pulp) is not particularly limited. In addition to hardwood or softwood, plants such as kenaf, hemp, rice, pacas, bamboo and the like may be used. .
- the pulp bleaching method of the second aspect of the present invention is characterized in that the pulp that has been subjected to the oxygen delignification treatment is acid-treated, and then bleached by a bleaching method used in ordinary TCF bleaching. After the light irradiation treatment with ultraviolet light and / or visible light, bleaching with alkaline hydrogen peroxide is performed.
- the type of acid used in the acid treatment of the present invention may be an inorganic acid or an organic acid.
- Mineral acids such as sulfuric acid, hydrochloric acid, nitric acid, sulfurous acid, nitrous acid, phosphoric acid, and residual acids from chlorine dioxide generators can be used as inorganic acids.
- it is sulfuric acid.
- As the organic acid acetic acid, lactic acid, oxalic acid, citric acid, formic acid, and the like can be used.
- the pH during the acid treatment is in the range of 1.0 to 6.0, preferably 1.0 to 5.0, more preferably 2.0 to 5.0, and optimally 2.5. ⁇ 3.5.
- the acid treatment can be carried out either under atmospheric pressure or under pressure, and the treatment temperature is from 80 ° C to 180 ° C, preferably from 80 ° C to 130 ° C.
- the temperature is 30 ° C or higher and lower than 80 ° C, there is an effect in terms of metal removal, but there is no effect of removing hexeneduronic acid. If the temperature is lower than 100 ° C, a pressure-resistant reaction vessel is not required, which is advantageous in terms of equipment cost.
- the pulp concentration at the time of the acid treatment is in the range of 0 :! to 50% by weight, preferably 1.0 to 30% by weight. %, More preferably 2.0 to 20% by weight.
- the effect of removing hexeneduronic acid and harmful metals is determined by the pH, reaction temperature, and reaction time during acid treatment. From this, the reaction time is appropriately set according to the other two conditions.
- the reaction time at a reaction temperature of 90 ° C is 1.5 to 6 hours
- the reaction time at a reaction temperature of 95 ° C is 50 minutes to 5 hours
- the reaction time at a reaction temperature of 100 ° C. is 30 minutes to 4.5 hours
- the reaction temperature is 120 to:
- the reaction time at 130 ° C. is 5 to 50 minutes.
- Ozone bleaching performed under acidic conditions is also one form of the acid treatment targeted in the present application, and ordinary conditions for acidic ozone bleaching can be applied.
- the general acidic ozone bleaching conditions are as follows: ozone gas having an ozone concentration of 1 to 20% by weight, pH 1.0 to 8.0 (1 and 3 of the first invention) or ⁇ 1 to 7 (this In 2) of the invention, the pulp concentration is preferably 0 :! to 50% by weight, and the temperature is preferably 25 to 95 ° C.
- the pressure here is not particularly limited from a negative pressure state to a pressurized state.
- dewatering and / or washing of the treated pulp is performed after the acid treatment including ozone, and these can be performed using a known dehydrator and / or washing machine in pulp production.
- dehydrator and / or washing machine in pulp production for washing, in addition to fresh water, bleaching wastewater generated in the bleaching step after acid treatment or papermaking wastewater generated in the papermaking process can be used.
- the acid-treated pulp is irradiated with ultraviolet light and / or visible light having a wavelength of 100 to 400 nm under alkaline conditions.
- alkaline conditions pH is 10 to: 13 is preferred.
- the acid-treated pulp is treated under an alkaline condition or an acidic condition.
- the alkaline condition is preferably pH 10-13, and the acidic condition is preferably pH 2-4.
- a normal alkaline agent can be used, but sodium hydroxide, potassium hydroxide, sodium silicate, and sodium carbonate are particularly preferable from the viewpoint of easy handling. .
- the pulp concentration during the light irradiation treatment of the present invention is preferably from 0.1 to 12% by weight.
- the content is less than 0.1% by weight, the efficiency of the bleaching reaction is increased, but the energy efficiency is lowered, which is not preferable. If the content exceeds 12% by weight, the fluidity of the pulp slurry in the irradiation device deteriorates, and the efficiency of the bleaching reaction decreases, which is not preferable.
- the temperature of the pulp slurry during this irradiation treatment is preferably 20 to 95 ° C. If the temperature is less than 20 ° C, the bleaching reaction efficiency is low. This is not preferable in that there is a possibility that the quality will deteriorate, or the pressure in the reactor will exceed the atmospheric pressure, so that it is necessary to design the device in consideration of the pressure resistance.
- the wavelength of the light to be irradiated is preferably 100 to 400 nm, but is preferably 200 to 360 nm (180 to 360 nm in 2 of the first invention). No. If the wavelength is less than 100 nm, the photolysis of cellulose is accelerated, resulting in a significant decrease in pulp strength. If the wavelength is greater than 400 nm, the photobleaching properties are significantly reduced due to insufficient photoexcitation of the photo-colored substance. , ⁇ , the deviation is also preferable.
- a light source for irradiation a light source having light in a wavelength region of 100 to 400 nm can be used.
- a xenon short arc lamp an ultra-high pressure mercury lamp, a high pressure mercury lamp, a low pressure mercury lamp, a deuterium lamp, a metal halide lamp, etc.
- a xenon short arc lamp an ultra-high pressure mercury lamp, a high pressure mercury lamp, a low pressure mercury lamp, a deuterium lamp, a metal halide lamp, etc.
- the degree of irradiation of the pulp in the irradiation reactor can be arbitrarily set by adjusting the residence time of the pulp in the irradiation reactor, adjusting the energy amount of the irradiation light source, or the like. .
- the pulp concentration in the irradiation device may be adjusted by dilution with water, or may be adjusted. Is to adjust the pulp concentration by blowing an inert gas such as air or nitrogen into the pulp slurry. These conditions can be appropriately set according to the target pulp quality (whiteness etc.) after the light irradiation reaction.
- the second aspect of the first invention is characterized in that the irradiation treatment with ultraviolet light and / or visible light having a wavelength of 100 to 400 nm is performed in the presence of ozone.
- ozone is generated because air usually exists in the gas layer around the light source.
- Ozone can be used as a reaction aid. Further, by supplying oxygen to the gas layer around the light source, a larger amount of ozone can be obtained.
- the generated ozone can be used for ordinary ozone bleaching, not only as an aid during the light irradiation reaction.
- Ozone generated as a by-product in the light irradiation reaction device can be used.
- Ozone can also be generated by supplying such air or oxygen to the pulp to be treated around the light source.
- the concentration of ozone generated as a by-product in the light irradiation reaction device is 0.5 to 100 ppm, depending on the method of supplying air or oxygen and the concentration of oxygen. It is a major feature of the first invention 2 that even with such a low concentration of ozone, extremely high bleaching efficiency can be obtained in combination with light irradiation treatment.
- a plurality of light sources having a characteristic wavelength range of 100 to 400 nm and having different characteristic wavelengths are selected and used as light sources for a light irradiation reaction device. be able to. Specifically, a combination of a light source with high ozone generation efficiency with a narrow wavelength characteristic of 135 to 242 nm and a light source with a complete wavelength range of 100 to 400 nm suitable for light irradiation reaction is used. Higher bleaching efficiency
- reducing agents eg, NaBH, hydrazine, hydrogen
- oxidizing agents eg, oxygen, ozone
- peroxides eg, hydrogen peroxide
- Over Acetic acid, sodium percarbonate, sodium perborate hydrogen-donating organic compounds
- organic compounds for example, alcohol, linear amines such as ethylamine and getylamine, and cyclic amines as tetramethylpiperidine
- organic compounds having an acetyl group for example, ⁇ —Acetyl- ⁇ -butyrolataton, acetol, acetone
- ozone bleaching, hydrogen peroxide bleaching, or the like may be used alone or in combination as TCF bleaching used to bring the ISO whiteness to 70 to 75% in the pre-bleaching stage. Wear.
- ozone bleaching can be performed under ordinary ozone bleaching conditions.
- the ozone bleaching conditions may be such that ozone gas having an ozone concentration of 1 to 20% by weight is used, and the treatment is performed in the range of pH 8 to 0.1, pulp concentration of 0.1 to 50% by weight, and temperature of 25 to 95 ° C. .
- the pressure at the time of ozone bleaching is not particularly limited from a negative pressure state to a pressurized state.
- hydrogen peroxide bleaching can be performed under ordinary alkaline hydrogen peroxide bleaching conditions.
- alkaline hydrogen peroxide bleaching is performed when the hydrogen peroxide is added in the range of 0.1 to 2.0% by weight of pulp, ⁇ ⁇ 11 to 13, pulp concentration of 0.1 to 50% by weight, and temperature of 50 to 95 ° C. Just fine.
- the ISO bleaching degree is previously improved to 70 to 75% by ordinary TCF bleaching, so that the light bleaching processing time can be significantly shortened. Power costs for bleaching can be significantly reduced. Furthermore, if the whiteness is improved by 5% or more by light bleaching to bring the ISO whiteness to 75 to 80%, and then hydrogen peroxide bleaching is performed in the final bleaching stage, the hydrogen peroxide bleaching reaction is accelerated. A pulp with an ISO brightness of 84% or more can be obtained efficiently.
- FIG. 1 shows an example of a system using the light irradiation reaction device according to the present invention.
- the acid-treated pulp is received in the light irradiation raw material adjustment tank (10), and is adjusted to a temperature ⁇ ⁇ ⁇ ⁇ pulp concentration suitable for the light irradiation reaction while being stirred.
- the adjusted light irradiation raw material 1 is sent to the light irradiation reaction device (12) by the light irradiation reaction device supply pump (11).
- an auxiliary agent such as a reducing agent in the light irradiation reaction is added as a chemical before that.
- the auxiliary agent may be added to the light irradiation material adjustment tank (10), or both, depending on the properties of the auxiliary agent or the light irradiation reaction conditions.
- a gas can be supplied before entering the light irradiation reaction device (12).
- the residence time or irradiation reaction time can be arbitrarily adjusted.
- an inert gas such as air or nitrogen is suitable, and these are used as fine bubbles dispersed in a pulp slurry.
- a gas such as hydrogen, oxygen, or ozone is used among the photoreaction aids, it can be similarly supplied to the location shown in FIG.
- the pulp having the target pulp quality is finished and sent to the next step (C1: Pulp after light irradiation reaction 1).
- C1 Pulp after light irradiation reaction 1
- the pulp is recycled to repeat the light irradiation reaction (C2: Pulp after light irradiation reaction).
- the ratio of C1 and C2 can be set arbitrarily according to the target pulp quality.
- the irradiation reactor is basically composed of an irradiation light source unit and a pulp slurry container unit.
- light from the irradiation light source unit is irradiated on the pulp slurry.
- a gas such as air exists around the light source unit, and a partition wall is required. At that time, it is important to select the material of the partition wall so that the light energy passes through the partition wall without attenuation.
- hard glass when light having a wavelength longer than 300 nm is used, hard glass can be used. When light having a wavelength shorter than 254 nm is used, quartz glass can be used. .
- the material of the portion of the pulp slurry container that does not participate in the light transmission reaction it is possible to select an appropriate material from materials having little deterioration with respect to the wavelength of light used.
- FIG. 2 shows an example of the light irradiation reaction device.
- the acid-treated pulp is adjusted to a temperature ⁇ ⁇ ⁇ pulp concentration suitable for the light irradiation reaction, and if necessary, an auxiliary agent such as a reducing agent is added.
- a slurry (al) is added to this reaction layer (20). Injected from (25).
- the injected pulp slurry flows in the apparatus (20), and is subjected to an irradiation reaction by light generated by the light irradiation light source (22) and passed through the partition (21: quartz glass tube). ) Power is discharged.
- a gas can be supplied through an air diffuser (24) attached to the light irradiation reaction device (20).
- Residence time or irradiation reaction time can be adjusted arbitrarily.
- an inert gas such as air or nitrogen is suitable, and these are used as fine bubbles dispersed in a pulp slurry.
- the gas when a gas such as hydrogen, oxygen, or ozone is used among the photoreaction aids, the gas can be supplied through the air diffuser (24).
- Ozone is present in these gases.
- the exhaust gas containing this ozone is supplied to a diffuser (24)
- Ozone can be used as a reaction aid without injecting ozone from outside the system by injecting it into the pulp slurry in the light irradiation reaction device (20).
- the generated ozone can also be used for ordinary ozone bleaching other than the aid during the light irradiation reaction.
- a gas effective as an aid for the light irradiation reaction such as hydrogen, oxygen, and ozone, can be injected from the outside of the system and used together. Use of these gases can be arbitrarily set by installing three-way valves (23a, 23b).
- auxiliary equipment such as a temperature / ⁇ control device and a gas concentration detection device can be arbitrarily provided as necessary.
- the light irradiation treatment of the present invention can be repeated one or more times, and this includes the bleaching efficiency, the target pulp quality (whiteness), and the relationship with other bleaching methods to be combined. It can be set appropriately according to the situation.
- the example in which the light irradiation process is repeated once or more times is as follows. (1) Two or more light irradiation devices in FIG. 1 can be provided. In this case, it may be a series or a parallel. (2) A plurality of irradiation light sources (having the same or different characteristics) can be provided in the light irradiation device in FIG. (3) It can be recirculated in the system shown in Fig. 1.
- the bleaching method of the present invention can be arbitrarily combined with all other known bleaching methods, whether chlorine-based or non-chlorine-based. Specifically, the bleaching method of the present invention can be followed by another bleaching method, or another bleaching method can be followed by the bleaching method of the present invention. In particular, it is preferable to perform a hydrogen peroxide treatment after performing the bleaching of the present invention. These sequences can also be repeated multiple times, with washing steps between different bleaching methods. In addition, the bleaching sequence incorporating the light irradiation system can be repeated several times. Note that when performing a plurality of light irradiation treatments, it is preferable to perform cleaning after the light irradiation treatments.
- the present invention is a high-brightness chemical pulp having an ISO whiteness of 88% or more and a decrease in whiteness of 1.0% or less in a fading test described below. That is, when evaluating the fading property of conventional paper, it was common to evaluate by a fading test by heat, but according to the study of the present inventors, it was evaluated by the following fading test by ultraviolet light. Can do real paper It was found that it correlated well with fading.
- Hand-made paper was prepared in accordance with JIS P8222, and the temperature was adjusted to 30 ° C in accordance with J. TAPPI No. 21 Paper and paperboard in accordance with Method B of the fading test method (method using a xenon arc lamp type light resistance tester). After irradiating a xenon lamp with a light intensity of 67 WZm 2 for 30 minutes below, measure the ISO whiteness according to JIS P8148, and determine the rate of decrease from the ISO whiteness before processing.
- known cooking methods such as kraft cooking, polysulfide cooking, soda cooking, and alkali sulphite cooking can be used.
- the kraft cooking method is preferred.
- MCC, EMCC, ITC, Lo-solids method and the like are known as the cooking method, but can be applied to the present invention without particular limitation.
- Wood can be cooked under known conditions, for example, under the following conditions.
- the degree of sulfurization of the cooking liquor is 7 to 75%, preferably 15 to 45%
- the effective alkali addition rate is 5 to 30% by weight, preferably 10 to 25% by weight
- the cooking temperature is 140 to 170 °.
- the cooking method may be either a continuous cooking method or a batch cooking method, and the method of the cooking apparatus is not particularly limited.
- the chemical pulp used in the present invention is subjected to an oxygen delignification treatment through an unbleached chemical pulp obtained by a known digestion method, followed by washing, rough selection and fine selection steps.
- the conditions for oxygen delignification can be performed by a known method.
- the kappa monovalent after oxygen delignification is preferably in the range of 5 to 15, preferably? ⁇ 15, more preferably 8 ⁇ 12.
- This oxygen delignification treatment is carried out by a known medium concentration method or high concentration method.
- typical reaction conditions for the medium concentration method include a pulp solid concentration of 10 to 18% by weight, a temperature of 100 to 110 ° C, a reaction time of 60 to 120 minutes, and a reactor internal pressure of 3 to 6 kgZm 2.
- the sodium hydroxide addition rate and oxygen addition rate are adjusted according to the target kappa monovalent.
- the type of acid used for acid treatment of pulp can be either inorganic or organic.
- mineral acids such as sulfuric acid, hydrochloric acid, nitric acid, sulfurous acid, nitrous acid, phosphoric acid, and residual acid of a chlorine dioxide generator can be used.
- sulfuric acid As the organic acid, acetic acid, lactic acid, oxalic acid, citric acid, formic acid and the like can be used.
- the pH of the hardwood pulp during acid treatment is desirably in the range of 1.5 to 6.0, preferably 1.0 to 5.0, more preferably 2.0 to 5.0, and most preferably 2.5 to 3.5. If the pH is less than 1.0, hexeneduronic acid and metal ions are sufficiently removed. Excessive acid reduces the pulp viscosity significantly. On the other hand, if the pH exceeds 6.0, the acid concentration is too low to remove hexeneduronic acid and metal ions insufficiently. In the case of hardwood chemical pulp, if the pH at the time of acid treatment is 2.5 to 3.5, the temperature at the time of acid treatment can be lowered, which has the effect of reducing the acid treatment cost.
- the acid treatment can be performed either under atmospheric pressure or under pressure.
- the reaction temperature during acid treatment at atmospheric pressure is in the range of 80 ° C or higher and less than 100 ° C. Preferably it is 80-95 ° C, more preferably 80-90 ° C. When the temperature is 30 ° C or higher and lower than 80 ° C, it is effective in removing metals, but there is no effect of removing hexeneduronic acid.
- the pulp is subsequently bleached in a multi-stage bleaching step.
- the chemicals used are atomic chlorine (C), caustic soda (E), hypochlorite (H), chlorine dioxide (D), oxygen ( ⁇ ), hydrogen peroxide (P), ozone (Z).
- well-known bleaching agents such as sulfuric acid (A) and organic peracids, and bleaching aids. These can be suitably selected from these and used as bleaching chemicals.
- the bleaching sequence is not particularly limited.
- a sequence containing atomic chlorine and a chlorine-based bleaching chemical such as C / DE / OH D, or a atomic bleaching sequence such as D-E-D and ZE / O-D Chlorine free, ECF bleaching sequences, TCF bleaching sequences that do not use any chlorine-based chemicals, such as Z-E-P, A-Z-E / O-P, can be used.
- the bleached chemical pulp obtained by the above-described method is further subjected to irradiation treatment with ultraviolet light and / or visible light.
- the bleached chemical pulp before the light treatment is preferably bleached to have an ISO whiteness of 80% or more, preferably 86% or more.
- pulp with very high whiteness can be easily obtained by introducing a P stage before and after light treatment.
- Irradiation treatment with ultraviolet light and / or visible light is preferably performed under alkaline conditions.
- alkaline conditions a pH range of 10 to 13 is preferred.
- the alkali used for the pH adjustment is a basic alkali that can be used for alkaline chemicals. Is preferably sodium hydroxide.
- acid used for adjusting the pH ordinary acidic agents can be used, but sulfuric acid is preferred.
- the pulp concentration during irradiation treatment with ultraviolet light and / or visible light is preferably 0.1 to 12% by weight. If the content is less than 0.1% by weight, the efficiency of the bleaching reaction is increased, but the energy efficiency is reduced, which is not preferable. If the content is more than 12% by weight, the fluidity of the pulp slurry in the bleaching apparatus becomes poor, and the efficiency of the bleaching reaction is undesirably reduced.
- the temperature at the time of the irradiation treatment with ultraviolet light and / or visible light is not particularly limited, but is preferably 20 to 95 ° C.
- the temperature is lower than 20 ° C, the bleaching reaction efficiency is low.
- the temperature exceeds 95 ° C, the pulp quality may deteriorate or the pressure inside the reactor may exceed the atmospheric pressure. Both are not preferable in that a device design that takes into account is necessary.
- the irradiation time of ultraviolet light and / or visible light is appropriately determined by considering the structure and concentration of the latent coloring substance contained in the raw pulp.
- the ultraviolet light and / or visible light used in the present invention is not particularly limited, but it is desirable to use ultraviolet light and / or visible light having a wavelength of 100 to 400 nm, preferably about 200 to 360 nm. .
- ultraviolet light having a wavelength of less than 100 nm the photolysis of cellulose is accelerated, so that the pulp strength and whiteness are significantly reduced.
- ultraviolet light having a wavelength of more than 400 nm the photoexcitation of the coloring substances is insufficient due to insufficient light excitation. Both are not preferred because the bleaching properties are significantly reduced.
- a normal light source such as a low-pressure mercury lamp, a high-pressure mercury lamp, a xenon lamp, and various excimer lamps and various lasers can be used.
- a low-pressure mercury lamp When a large amount of pulp is processed, high output and ozone are generated. It is desirable to use a low-pressure mercury lamp.
- the ozone generating ultraviolet lamp mainly emits ultraviolet light having a wavelength of 254 nm, and also includes ultraviolet light having a wavelength of 185 nm and visible light.
- the irradiation intensity of ultraviolet light with a wavelength of 185 nm is not affected by temperature, but the intensity of ultraviolet light with a wavelength of 254 nm is temperature-dependent and becomes maximum at 20 to 40 ° C.
- high-power ozone generation lamps with a high lamp surface temperature use air to cool the lamp, and at the same time as cooling, generate ozone gas from oxygen in the air using ultraviolet light with a wavelength of 185 nm.
- this ozone gas is converted to ultraviolet light with a wavelength of 254 nm.
- strong reactive oxygen species are generated, and the decomposition of the coloring component is remarkably accelerated.
- the higher the ozone concentration the higher the treatment efficiency.
- ultraviolet light with a wavelength of 254 nm is the most effective ultraviolet light for bleaching.
- reducing agents include, for example, hydrosulfite and borohydride compounds; oxidizing agents include hydrogen peroxide, sodium percarbonate, and peracetic acid; and hydrogen-donating organic compounds include ethanol. Primary alcohol and the like.
- the additive in the present invention may be used alone without using a solvent, but is preferably used by dispersing or dissolving it in a solvent that transmits ultraviolet and visible light. In addition, different additives can be mixed and used.
- a solvent examples include a single solvent such as water, alcohols, chain or cyclic alkanes, and ethers or a mixed solvent thereof, and water is preferably used.
- the amount of the additive used is not particularly limited as long as it is lower than the saturation concentration of the additive with respect to the solvent, but is preferably 0.01 to 40% by weight, more preferably 0.1 to 20% by weight, based on the solvent. Is
- the paper containing the high-brightness chemical pulp of the present invention may be used for book paper, offset printing paper, letterpress printing paper, gravure printing paper, newsprint paper, electrophotographic paper, or coated paper in addition to book paper. It can be used as base paper for inkjet recording paper, thermal recording paper, pressure-sensitive recording paper, etc.
- Paper containing the high brightness chemical pulp of the present invention is less than the high brightness chemical pulp of the present invention.
- chemical pulp, mechanical pulp, and deinked pulp may be used alone or as a mixture at an arbitrary ratio as a raw material panolep.
- the pH during papermaking may be acidic, neutral or alkaline.
- the paper containing the high brightness pulp of the present invention may contain a paper strength enhancer.
- the paper strength agent include starch, modified starch, polyacrylanolamide, polybutyl alcohol, polyamide 'polyamine resin, urea' formalin resin, melamine 'formalin resin, polyethyleneimine, and the like.
- the content of the paper strength enhancer is preferably 0.1% by weight or more and 2% by weight or less based on the absolute dry weight of the pulp.
- the paper containing the high-whiteness pulp of the present invention may contain a filler.
- a filler known fillers such as white carbon, talc, kaolin, clay, heavy calcium carbonate, light calcium carbonate, titanium oxide and synthetic resin filler can be used.
- the paper containing the high-whiteness pulp of the present invention may contain, if necessary, a sulfate band, a size agent, a retention agent, a drainage agent, a coloring agent, a dye, a defoaming agent, a bulking agent, It may contain a fluorescent whitening agent and the like.
- the paper containing the high-whiteness pulp of the present invention may not be subjected to any coating treatment, or may be coated with a surface treatment agent containing no pigment.
- a surface treatment agent containing a water-soluble polymer as a main component for the purpose of improving the surface strength and size.
- a surface treating agent such as starch, modified starch, polyacrylamide, and polyvinyl alcohol can be used alone or in a mixture thereof.
- a paper strength enhancer for improving water resistance and surface strength and an externally added size agent for imparting sizing properties should be added to the surface treatment agent. Can be.
- the surface treatment agent can be applied by a coating machine such as a 2-roller size press coater, a gate roll recorder, a blade metering coater, and a rod metering coater. Is the coating amount of the surface treatment agent, per side O.LgZm 2 more 3GZm 2 or less.
- Measurement of monovalent kappa Measurement of monovalent kappa: It was performed according to JIS P 8211.
- FIG. 3 shows the experimental apparatus used in the example of the present application.
- the light irradiation reaction tank (1) As the light irradiation reaction tank (1), a 3L glass cylinder (100 mm X 620 mmH) was used. This light irradiation reaction vessel (1) is Stirring machine shown in FIG. (4), other diffusing pipe (5), and a temperature control unit and P H instrument.
- the light irradiation light source (16W low-pressure mercury lamp, AY-1 manufactured by Japan Photo Science Co., Ltd.) is installed in a quartz glass tube (45 mm ⁇ X 470 mmH, 2 mm thick), and air is injected around the light irradiation light source. It has a structure that can be used.
- Kraft panolep (Kappa monovalent 11.6, ISO whiteness 45.6%) after hardwood oxygen delignification manufactured by Nippon Paper Industries Co., Ltd. was used.
- Acid treatment was performed under the following conditions to obtain pulp having a kappa monovalent value of 5.5 and a whiteness of 47.5%.
- Acid treatment conditions pulp concentration 10% by weight, pH 3.0 (using sulfuric acid), temperature 95 ° C, treatment time 180 minutes. After the treatment, the pulp was washed with water.
- ozone treatment was performed under the following conditions to obtain pulp having a kappa monovalent value of 3.0 and a whiteness of 56.6%.
- Ozone treatment conditions pulp concentration of 10. /. , Ozone added 7kg ZADTP, temperature 50 ° C, treatment Time 30 seconds, pH 2.5 (using sulfuric acid).
- Acid treatment conditions pulp concentration 10% by weight, pH3 (sulfuric acid added) temperature 95 ° C, treatment time 180 minutes
- Kraft panolep (Kappa monovalent 9.5, ISO whiteness 47.5%) after hardwood oxygen delignification manufactured by Nippon Paper Industries Co., Ltd. was used.
- Acid treatment was performed under the following conditions to obtain pulp having a kappa monovalent value of 5.5 and a whiteness of 48.6%.
- Acid treatment conditions pulp concentration 10% by weight, pH 3 (adding sulfuric acid), temperature 85 ° C, treatment time 180 minutes. After the treatment, the pulp was washed with water.
- Ozone treatment conditions pulp concentration 10. /. , Ozone-added syrup quantity 7kg ZADTP, temperature 55 ° C, treatment time 30 seconds, pH 2.5.
- FIG. 3 shows the experimental apparatus used in the examples.
- a 4L glass cylinder 100 mm X 620 mmH was used.
- the light irradiation reaction tank (20) is equipped with a stirrer (27) and an air diffuser (24) as shown in the figure, a temperature controller and a pH meter.
- the light irradiation light source (16W low-pressure mercury lamp, AY-1 manufactured by Japan Photo Science Co., Ltd.) is installed in a quartz glass tube (25 mm x 470 mmH, 2 mm thick), and air is injected around the light irradiation light source. It has a structure that can be used. In this embodiment, two light irradiation light sources were used. [Example 9]
- Hardwood Kraft Panolep (Kappa monovalent 11.6, ISO whiteness 45.6%) after oxygen delignification manufactured by Nippon Paper Industries Co., Ltd., pulp concentration 10% by weight, pH 3.0 (adjusted with sulfuric acid), temperature
- the acid treatment was performed at 95 ° C for 180 minutes. After the completion of the acid treatment, the pulp was washed with water, and the obtained pulp had a kappa monovalent value of 5.5 and a whiteness of 47.5%.
- Example 11 in which irradiation treatment was performed with ultraviolet light or visible light or a combination thereof in the presence of ozone, it was possible to produce pulp with higher whiteness. However, in Example 11, in which the irradiation treatment was not performed under acidic conditions of pH 2 to 4 or under alkaline conditions of pHIOIO: 13, the whiteness was slightly inferior.
- Pulp whiteness measurement After the pulp was defibrated, a sheet having a basis weight of 60 g / m 2 was prepared according to JIP P8222, and the ISO whiteness of the pulp was measured according to JIS P8148.
- Kraft panolep (ISO whiteness 45.6%, manufactured by Nippon Paper Industries Co., Ltd.) after oxygen delignification of hardwood was used, and further subjected to acid treatment ozone bleaching under the following conditions, and used in Examples and Comparative Examples. did.
- Kraft panolep after oxygen delignification of the hardwood was subjected to acid treatment at a pulp concentration of 10% by weight, a pH of 3.0 (using sulfuric acid) at a temperature of 95 ° C, and a treatment time of 180 minutes. After the treatment, the pulp was washed with water. At this time, the ISO brightness of the pulp was 47.5%.
- ozone bleaching of the pulp after acid treatment is performed at a pulp concentration of 10%, an ozone addition amount of 7 kg / (air-dried pulp It), a temperature of 50 ° C, a treatment time of 30 seconds, and a pH of 2.5 (using sulfuric acid). went. After the treatment, the pulp was washed with water. At this time, the ISO whiteness of the pulp was 59.7%.
- the pulp after the ozone bleaching was further bleached in the bleaching sequence of hydrogen peroxide bleaching 1 light bleaching—hydrogen peroxide bleaching 2 under the following conditions.
- Hydrogen peroxide bleaching 1 Pulp concentration 10% by weight, pH 1.1 (using sodium hydroxide), temperature 75 ° C, processing time 90 minutes. After the treatment, the pulp was washed with water. At this time, the ISO whiteness of the pulp was 75.0%.
- the bleaching process was performed under the same conditions as in Example 1 except that the processing time was changed to 30 minutes.
- the ISO whiteness after light bleaching was 80.0%.
- the obtained pulp after the light bleaching treatment was treated under the conditions of the hydrogen peroxide bleaching 2 described above. Finally, the ISO whiteness was 86.1%.
- the treatment was carried out under the same conditions as in Example 1 except that the treatment time was changed to 45 minutes in hydrogen peroxide bleaching 1.
- the ISO whiteness after hydrogen peroxide bleaching 1 was 71.0%.
- the ISO whiteness after light bleaching was 74.5%.
- the obtained pulp was treated under the same conditions as in the hydrogen peroxide bleaching 2 described above. Finally, the ISO whiteness was 84.1%.
- the pulp was bleached in a bleaching sequence of light bleaching hydrogen peroxide bleaching.
- Light bleaching was performed under the same conditions as in Example 12 except that the processing time was changed to 60 minutes.
- the whiteness after light bleaching was 75.4%.
- the resulting pulp was treated under the same conditions as in hydrogen peroxide bleaching 2 of Example 12. Finally, the ISO whiteness was 84.3%.
- Example 4 The procedure was performed under the same conditions as in Example 4 except that the processing time for light bleaching was changed to 120 minutes.
- the ISO whiteness after light bleaching was 81.8%.
- the resulting pulp was treated with hydrogen peroxide bleach 2 of Example 12. Processed under the same conditions. Finally, the ISO whiteness was 85.2%.
- the treatment was carried out under the same conditions as in Example 12, except that the treatment time was changed to 30 minutes in hydrogen peroxide bleaching 1.
- the ISO whiteness after hydrogen peroxide bleaching 1 was 68.2%.
- the ISO whiteness after light bleaching was 72.3%.
- the obtained pulp was treated under the same conditions as in the hydrogen peroxide bleaching 2 described above. Finally, the ISO whiteness was 81.7%.
- the pulp was bleached in a bleaching sequence of hydrogen peroxide bleaching 1 hydrogen peroxide bleaching 2.
- the bleaching treatment was performed under the same conditions as in Example 12 except that the light bleaching treatment was not performed.
- the ISO whiteness was 79.3%.
- the pulp was bleached in a bleaching sequence of hydrogen peroxide bleaching 1 light bleaching.
- Light bleaching was performed under the same conditions as in the example except that the processing time was changed to 60 minutes.
- Hydrogen peroxide bleaching 1 was bleached under the same conditions as in Example 12.
- the ISO whiteness was 83.3%.
- the pulp was bleached in a bleaching sequence of hydrogen peroxide bleaching, 1 light bleaching, and hydrogen peroxide bleaching.
- the bleaching treatment was performed under the same conditions as in Example 1 except that the light bleaching was performed at pH 4.0 (sulfuric acid).
- the whiteness after light bleaching was 75.9%.
- the resulting pulp was treated under the same conditions as for hydrogen peroxide bleaching 2 of Example 12. Finally, the ISO whiteness was 82.6%.
- Table 6 shows the results of Examples 12 to 17 and Comparative Examples 7 to 9.
- CSF Freeness
- 'Measurement of whiteness of pulp After disintegrating panolep, a hand-made sheet having a basis weight of 60 g / m 2 was prepared according to JIS P8222, and the ISO whiteness of the pulp was measured according to JISP8148.
- 'Measurement of breaking length After disintegrating panolep, a sheet having a basis weight of 60 g / m 2 was prepared according to JIS P8222, and the breaking length was measured according to JISP8113.
- 'Discoloration test Performed using a xenon lamp weather meter. After irradiating the sample with ultraviolet rays generated from a xenon lamp for 30 minutes, the ISO whiteness CJIS P 8148) was measured. The fading test was performed at a temperature of 30 ° C. and a light amount of 67 W / m 2 .
- the ⁇ whiteness and whiteness reduction rate in Table 1 are defined as follows.
- ⁇ whiteness ISO whiteness after fading test-ISO whiteness before fading test
- Whiteness reduction rate ⁇ whiteness / ISO whiteness before color fading test
- UV light bleaching experimental device The experimental device used in the examples is shown in FIG. 72.1 ⁇ ( ⁇ ) ⁇ 11
- a low-pressure ultraviolet lamp (95W, 18mm ( ⁇ )) XI 100mm (H) at the center of a glass cylindrical ultraviolet light irradiation reaction tank (effective volume 2.64L) of 80mm ( ⁇ ) ), SUV110D manufactured by Sen Special Light Source Co., Ltd. is fixed, and the generated ozone gas (540 mg / h) is introduced from the lower part of the reaction tank, and moves upflow in the reaction tank together with the pulp slurry.
- the pulp slurry passed through a stock tank (capacity: 30 L) and was then pumped so that it could be repeatedly sent to the reaction tank.
- Nippon Paper Industries B Mill Ozone ECF bleaching method [Acid treatment (oxygen delignified pulp concentration 10% by weight, pH3 (sulfuric acid added), temperature 85 ° C, treatment time 180 minutes), ozone treatment (pulp concentration 10% %, PH 2.5 (sulfuric acid added), ozone added 7 kg / air-dried pulp U, temperature 55 ° C, processing time 30 seconds)], 200 g bleached hardwood pulp (ISO brightness 84.9%) Volume), the pulp concentration was adjusted to 1%, and the pH was adjusted to 1.5 with sodium hydroxide. This slurry was injected into the experimental apparatus shown in Fig. 7, and subjected to ultraviolet light bleaching at a temperature of 25 ° C and a processing time of 120 minutes with stirring.
- Nippon Paper Stock Society ne tA taken plants bleached hardwood pulp (ISO whiteness 86./ 0) obtained by the chlorine bleaching process of LOOG (absolute dry weight), was a pulp concentration of 10% sodium hydroxide The pH was adjusted to 1.5 by adjusting the pH. The slurry was bleached with hydrogen peroxide at a temperature of 50 ° C. for 180 minutes at a temperature of 50 ° C. After the treatment, the pulp was washed, a sheet was prepared, and the whiteness was measured. The sheet after the whiteness measurement was used for the fading test. Further, a sheet was prepared from the pulp after the beating treatment, and the breaking length was measured. Table 7 shows the results.
- Sheets were prepared using bleached hardwood pulp (ISO whiteness 89.3%) obtained by a commercially available chlorine dioxide ECF bleaching method, and the whiteness was measured. The sheet after the whiteness measurement was used for the fading test. Further, a sheet was prepared from the pulp after the beating treatment, and the breaking length was measured. The results are shown in Table 7.
- Sheets were prepared using hardwood bleached pulp (ISO whiteness 85.6%) obtained by the chlorine bleaching method of Nippon Paper Industries Co., Ltd. ⁇ A mill, and the whiteness was measured. The sheet after the whiteness measurement was used for the fading test. In addition, a sheet was prepared from the pulp after the beating treatment, and the breaking length was measured. The results are shown in Table 7.
- a sheet was prepared using bleached hardwood pulp (ISO whiteness: 84.9%) obtained by the chlorine bleaching method of Nippon Paper Industries Co., Ltd. B factory, and the whiteness was measured. The sheet after the whiteness measurement was used for the fading test. In addition, a sheet was prepared from the pulp after the beating treatment, and the breaking length was measured. The results are shown in Table 7.
Abstract
A method for bleaching a pulp, which comprises irradiating an acid-treated and washed pulp with an ultraviolet and/or visible light having a wavelength of 100 to 400 nm under an alkaline condition, preferably at a pH in the range of 10 to 13; the bleaching method, wherein the acid treating is carried out under the condition of a pH of 1 to 6 and a temperature of 80°C or higher; and the bleaching method, wherein the light is irradiated in the presence of at least one compound selected from the group of a reducing agent, a peroxide and a hydrogen-donating organic compound; and a highly white chemical pulp which has a ISO whiteness of 88 % or higher and exhibits a decreasing rate for the whiteness in a prescribed discoloration test of 1.0 % or less. The above bleaching method is a technology having been attained by further developing a conventional acid treatment or light irradiation of a pulp, and it reduces the use of a chlorine-containing chemical and is markedly efficient and more efficient as compared to a conventional technology. The above pulp is reduced in the load on the environment, is free from discoloration, and is an excellent pulp having high whiteness.
Description
明 細 書 Specification
パルプの漂白方法 Pulp bleaching method
技術分野 Technical field
[oooi] 本発明は、酸処理後洗浄したパルプをアルカリ性条件下で、紫外光及び Z又は可 視光を照射することを特徴とするパルプの漂白方法、酸処理後洗浄したパルプに、 紫外光及び/又は可視光用による照射処理とオゾン添加とを組み合わせた処理を することによって、パルプの漂白を促進させることを特徴とする漂白方法、及び高白 色度の化学パルプを得ることができる化学パルプの漂白方法（以上を第 1発明という [oooi] The present invention provides a method for bleaching pulp, which comprises irradiating pulp washed after acid treatment with ultraviolet light and Z or visible light under alkaline conditions. And / or a bleaching method characterized by accelerating the bleaching of pulp by performing a treatment combining irradiation treatment with visible light and ozone addition, and a chemical method capable of obtaining a chemical pulp having a high degree of whiteness. Pulp bleaching method (the above is referred to as the first invention)
。）、並びに退色性が大幅に改善された高白色度化学パルプ、及びそれを含有する 紙に関し、更に詳しくは漂白された化学パルプをさらに紫外光処理することによって 得られる退色性が大幅に改善された新規な高白色度化学パルプ、及びそれを含有 した紙 (第 2発明という。）に関するものである。 . ), And high brightness chemical pulp having significantly improved fading, and paper containing the same, more particularly, the bleaching obtained by further treating the bleached chemical pulp with ultraviolet light. A new high-brightness chemical pulp and paper containing the same (referred to as the second invention).
背景技術 Background art
[0002] 後述する第 1発明の背景技術は、次のとおりである。 [0002] The background art of the first invention described below is as follows.
[0003] 紙パルプ工場の漂白工程から排出される物質が環境に与える影響に関心が集まる 中、従来の塩素若しくは塩素系薬品又はこれらの組み合わせを主に用いた漂白方 法から、塩素を使わない非塩素 (ECF)漂白や更に進んで塩素系薬品を全く使用し ない完全無塩素 (TCF)漂白が全世界的に主流となりつつある。このような背景から、 ECF漂白や TCF漂白で使用される薬品としては、二酸化塩素や過酸化水素、酸素 、オゾンなどの薬品類に限定されてきている。しかしながら、これらの薬品のみでは、 組合せも自ずと限定されることもあり、漂白によって得られるパルプ品質、特に白色度 には限界があり、あるいはそれを得るためには高価な薬品を大量に使用しなければ ならない等の問題がでてきている。これらの問題を解決するために、これまでにない 漂白性能に優れた非塩素系薬品、あるいは新たな漂白方法の開発が求められてい る。 [0003] While concern has been placed on the environmental impact of substances emitted from the bleaching process of pulp and paper mills, chlorine is not used in conventional bleaching methods that mainly use chlorine or chlorine-based chemicals or a combination thereof. Non-chlorine (ECF) bleaching and even more completely chlorine-free (TCF) bleaching, which uses no chlorine-based chemicals, are becoming mainstream worldwide. Against this background, the chemicals used in ECF and TCF bleaching have been limited to chemicals such as chlorine dioxide, hydrogen peroxide, oxygen and ozone. However, the combination of these chemicals alone may be naturally limited, and the pulp quality, especially whiteness, obtained by bleaching is limited, or expensive chemicals must be used in large amounts to obtain them. There are problems such as the need to do so. In order to solve these problems, there is a need for the development of non-chlorine chemicals with superior bleaching performance, or new bleaching methods.
[0004] 従来からパルプに由来する各種の金属が酸素系漂白薬品の分解を促進し、酸素 系漂白薬品を無駄に消費することが知られている。そこで、この金属を除去し、酸素
系漂白薬品の漂白効率を高める技術として、比較的低温の酸処理若しくはキレート 剤処理又はこれらの組み合わせた処理などが提示されてレ、る。この酸処理の技術と して、リグノセルロース材料力 製造されたパルプを酸素漂白によって脱リグニンする 方法において、まず、パルプに亜硝酸塩及び酸を添加してパルプを前処理し、続い て酸素漂白を行う漂白方法、あるいは蒸解処理された化学パルプに対して、酸処理 を行った後、アルカリ性媒体中で過酸ィヒ物と加圧酸素による脱リグニンを行う漂白方 法が開示されている（例えば、特許文献 1、特許文献 2)。また、このほか、蒸解処理さ れた化学パルプに対して、高温高圧酸素漂白処理を行い、次いで酸処理またはキレ ート剤処理を行った後、アルカリ性媒体中で過酸化物、または過酸化水素と酸素に より脱リグニン ·漂白を行う漂白方法が開示されている（例えば、特許文献 3)。 [0004] Conventionally, it is known that various metals derived from pulp accelerate the decomposition of oxygen-based bleaching chemicals and wastefully consume oxygen-based bleaching chemicals. So, this metal is removed and oxygen As a technique for increasing the bleaching efficiency of a system bleaching chemical, acid treatment at relatively low temperature, treatment with a chelating agent, or a combination of these treatments has been proposed. As a technology of this acid treatment, in a method of delignifying pulp produced by lignocellulosic material by oxygen bleaching, first, nitrite and an acid are added to the pulp to pretreat the pulp, followed by oxygen bleaching. A bleaching method has been disclosed in which a bleaching method is carried out, or a bleaching method in which a digested chemical pulp is subjected to an acid treatment and then delignification with a peracid product and pressurized oxygen in an alkaline medium (for example, , Patent Document 1, Patent Document 2). In addition, the digested chemical pulp is subjected to high-temperature and high-pressure oxygen bleaching, followed by acid treatment or chelating agent treatment, and then peroxide or hydrogen peroxide in an alkaline medium. A bleaching method for delignification and bleaching using oxygen and oxygen is disclosed (for example, Patent Document 3).
[0005] また、 ECFまたは TCF漂白パルプの退色に係わる物質に関する最近の新たな知 見として、従来のリグニンやその変性物以外にへキセンゥロン酸が関与していること が知られ出している。このへキセンゥロン酸は、蒸解工程においてへミセルロース中 のメチルダルクロン酸力 脱メチルすることで生成する。このへキセンゥロン酸はパル プの退色性に関与していると言われている。このへキセンゥロン酸を除去する方法の 一つとして、比較的高温の酸処理技術が提示されている。これは、漂白前のパルプ を高温、かつ酸性条件下で処理することにより、このへキセンゥロン酸およびリグニン 変性物を酸加水分解し除去するものである。例えば、硫酸塩法またはアルカリ法によ つて製造したセルロースパルプの懸濁液を加熱し、約 85〜150°C、約 pH2〜5で処理 し、セルロースパルプ中のへキセンゥロン酸の少なくとも約 50%を除去し、パルプの力 ッパー価を 2〜9単位減少させる技術が開示されてレ、る（特許文献 4参照）。 [0005] Further, as a recent new finding on a substance related to the fading of bleached ECF or TCF pulp, it has been known that hexeneduronic acid is involved in addition to conventional lignin and its modified products. This hexeneduronic acid is produced by demethylation of methyldalcuronic acid in hemicellulose in the digestion step. This hexeneduronic acid is said to be involved in the bleaching of the pulp. As one of the methods for removing hexeneduronic acid, an acid treatment technique at a relatively high temperature has been proposed. This is to treat the pulp before bleaching at high temperature and under acidic conditions to remove the hexeneduronic acid and the modified lignin by acid hydrolysis. For example, a suspension of cellulose pulp produced by the sulfate or alkali method is heated and treated at about 85-150 ° C and about pH 2-5, so that at least about 50% of the hexeneduronic acid in the cellulose pulp is obtained. A technique has been disclosed for removing pulp and reducing the pulp number of pulp by 2 to 9 units (see Patent Document 4).
[0006] また、光照射を利用する漂白技術として、未晒クラフトパルプの過酸化水素漂白に おいて紫外光を照射する技術 (例えば、非特許文献 1、あるいは特許文献 5参照）、 あるいは未晒クラフトパルプの酸素漂白におレ、て紫外光を照射する技術 (例えば、非 特許文献 2、参照参照）が開示されている。さらに、通常のアルカリ性過酸化水素漂 白を促進する前処理として過酸化物共存下で紫外光を照射する技術 (例えば、特許 文献 6参照）が開示されている。 [0006] As a bleaching technique using light irradiation, a technique of irradiating ultraviolet light in hydrogen peroxide bleaching of unbleached kraft pulp (for example, see Non-Patent Document 1 or Patent Document 5) or unbleached pulp A technique of irradiating ultraviolet light to oxygen bleaching of kraft pulp (see, for example, Non-Patent Document 2) is disclosed. Further, a technique of irradiating ultraviolet light in the presence of a peroxide as a pretreatment for accelerating the bleaching of alkaline hydrogen peroxide (for example, see Patent Document 6) is disclosed.
[0007] また、還元剤を用いるパルプの漂白方法において紫外光若しくは可視光又はこれ
らを併用した光を照射する技術 (特許文献 7参照）、あるいは酸化剤として ROOR'で 示される有機過酸化物の存在下、紫外光若しくは可視光又はこれらを併用した光を 照射する技術 (特許文献 8参照）、が開示されている。 [0007] Further, in a pulp bleaching method using a reducing agent, ultraviolet light or visible light or (Patent Document 7), or UV or visible light or a combination of these in the presence of an organic peroxide represented by ROOR 'as an oxidizing agent (Patent Reference 8) is disclosed.
[0008] また、近年、産業排水、生活排水など水の汚染が進んでおり、水環境汚染が社会 問題になっている。この様な背景のもとに、水環境保全技術の開発が活発に行われ ており、活性炭処理、膜処理、オゾン処理、紫外線処理、生物学的な処理などの技 術開発が行われている。それらの中で、総合的な処理として有望とされている、ォゾ ンと、紫外線を組み合わせた促進酸化技術 (特許文献 9参照）があり、分解効率の向 上、脱臭、脱色、殺菌作用の向上を図ることができ、さらには二次廃棄物を生じさせ なレ、浄化処理を行なうことができる。 [0008] In recent years, water pollution such as industrial wastewater and domestic wastewater has been progressing, and water environmental pollution has become a social problem. Against this background, the development of water environment conservation technologies is being actively conducted, and technologies such as activated carbon treatment, membrane treatment, ozone treatment, ultraviolet treatment, and biological treatment are being developed. . Among them, there is a promising oxidation technology that combines ozone and ultraviolet light (see Patent Document 9), which is promising as a comprehensive treatment, and improves decomposition efficiency, deodorization, decolorization, and bactericidal action. Improvements can be achieved, and further, purification treatment can be performed without generating secondary waste.
特許文献 1：特許第 2895977号公報 Patent Document 1: Japanese Patent No. 2895977
特許文献 2：特開平 6— 101186号公報 Patent Document 2: JP-A-6-101186
特許文献 3 :特開平 6— 158573号公報 Patent Document 3: JP-A-6-158573
特許文献 4：特表平 10— 508346号公報 Patent Document 4: Japanese Translation of PCT International Publication No. 10-508346
特許文献 5 :特開 2002— 88673号公報 Patent Document 5: JP-A-2002-88673
特許文献 6：特開平 6— 128890号公報 Patent Document 6: JP-A-6-128890
特許文献 7 :特開 2002— 88671号公報 Patent Document 7: JP-A-2002-88671
特許文献 8 :特開 2002— 88672号公報 Patent Document 8: JP-A-2002-88672
特許文献 9：特開 2004— 97992号公報 Patent Document 9: Japanese Patent Application Laid-Open No. 2004-97992
非特許文献 1 : B.Marccia,et al. J34〜J39、 JOURNAL OF PULP AND PAPER SCIEN CE:Vol. l7,No.2,March 1991 Non-Patent Document 1: B. Marccia, et al. J34 to J39, JOURNAL OF PULP AND PAPER SCIEN CE: Vol. L7, No. 2, March 1991
非特許文献 2 : J. Abbot, et al. pl98〜202、 Appita Vol.46,No.3,May 1993 後述する第 2発明の背景技術は、次のとおりである。 Non-Patent Document 2: J. Abbot, et al. Pl98-202, Appita Vol. 46, No. 3, May 1993 The background art of the second invention described below is as follows.
[0009] 化学パルプを主原料とする紙製品、特にインクジェット用紙、熱転写記録用紙など の情報記録用紙や写真用印画紙支持体などにおいては高い白色度が要求される。 通常、未漂白クラフトパノレブの白色度を高めるために、塩素、次亜塩素酸塩、二酸化 塩素、酸素、過酸化水素、オゾンなどの化学薬品で多段漂白することにより未漂白パ ルプに残留するリグニンや多糖類由来の着色原因物質を除去している。塩素ガスに
よる塩素漂白法、さらに有機塩素化合物の生成を低減した点でより環境に優しい二 酸化塩素による ECF漂白法で得られたパルプの ISO白色度は通常 82〜86%である 。 白色度が通常以上に高いレベルまで漂白された高白色度パルプは蒸解及び/ま たは漂白条件を強化する、或いはフエノール性の抽出成分含有量の少ない易蒸解 および漂白性の樹種を利用するなどの方法で製造されるのが一般的である。 High whiteness is required for paper products using chemical pulp as a main raw material, particularly for information recording paper such as ink-jet paper and thermal transfer recording paper, and for photographic paper support. Usually, unbleached kraft panolebs remain in unbleached pulp by multi-stage bleaching with chemicals such as chlorine, hypochlorite, chlorine dioxide, oxygen, hydrogen peroxide, ozone, etc. It removes coloring substances derived from lignin and polysaccharides. Chlorine gas The pulp obtained by the chlorine bleaching method and the ECF bleaching method with chlorine dioxide, which is more environmentally friendly in that the production of organic chlorine compounds is reduced, usually has an ISO whiteness of 82 to 86%. High brightness pulp that has been bleached to an unusually high level of whiteness will enhance cooking and / or bleaching conditions, or use readily digestible and bleaching tree species with low phenolic extractables. It is generally manufactured by the method described above.
高白色度パルプを製造する従来の技術としては、例えば、漂白工程として、少なく とも一段以上の塩素系の漂白段を含むシーケンスによって漂白されたパルプを、キ シラナ一ゼで処理し、更に次亜塩素酸塩段と二酸化塩素段の漂白シーケンスで漂 白することを特徴とする高白色度パルプの製造方法が開示されている（特許文献 10 参照）。また、リグノセルロース物質より得られた漂白パルプを、更に高温 '高アルカリ ハイポ晒段と二酸化塩素晒段の連続したシーケンスからなる工程で漂白する高白色 度パルプの製造方法において、該ニ酸化塩素晒段の工程が、二酸化塩素添加率 1 〜3重量％ (対絶乾パルプ）で、かつ 91°C以上 100°C未満の高温で実施されることを 特徴とする高白色度パルプの製造方法が開示されている（特許文献 11参照)。また 、漂白シーケンスが酸素漂白 オゾン漂白 アルカリ抽出 過酸化水素漂白一二 酸化塩素漂白 過酸化水素漂白 二酸化塩素漂白であり、該オゾン漂白工程で絶 乾パルプに対して 0.1〜1.0重量％のオゾンを用いて漂白された化学パルプであるこ とを特徴とする写真印画紙用支持体原紙について開示されている（特許文献 12参 照）。さらに、カッパ一価が 23以下の未晒クラフトパルプを脱リグニン度 40%以上で酸 素漂白し、次いでパルプ濃度 25%以上でオゾン漂白した後、 PN価を 2.8以下とし、 過酸化水素漂白と二酸化塩素漂白を含む多段漂白を行うことを特徴とする退色性の 優れた感材用高白色度パルプの製造方法が開示されている（特許文献 13参照）。し かし、従来の方法で得られた高白色度パルプ中には熱や紫外線で濃色化する極微 量の潜在的な着色物質が残存しており、経時で白色度が低下する、いわゆる退色現 象を避けるのが困難であった。 Conventional techniques for producing high brightness pulp include, for example, bleaching a pulp bleached by a sequence including at least one chlorine-based bleaching step, treating the pulp with xylanases, A method for producing high brightness pulp characterized by bleaching in a bleaching sequence of a chlorate stage and a chlorine dioxide stage has been disclosed (see Patent Document 10). Further, in the method for producing a high-whiteness pulp in which the bleached pulp obtained from the lignocellulosic material is bleached in a process consisting of a continuous sequence of a high-temperature high-alkali hypo bleaching stage and a chlorine dioxide bleaching stage, the chlorine dioxide bleaching The high-brightness pulp manufacturing method is characterized in that the step of the step is carried out at a high temperature of 91 ° C or higher and lower than 100 ° C with a chlorine dioxide addition rate of 1 to 3% by weight (based on absolute dry pulp). It has been disclosed (see Patent Document 11). The bleaching sequence is oxygen bleaching, ozone bleaching, alkali extraction, hydrogen peroxide bleaching, hydrogen peroxide bleaching, hydrogen peroxide bleaching, chlorine dioxide bleaching, and the ozone bleaching step uses 0.1 to 1.0% by weight of ozone based on absolutely dry pulp. A support base paper for photographic printing paper, characterized in that it is a chemical pulp bleached (see Patent Document 12). In addition, unbleached kraft pulp with a kappa monovalent of 23 or less is bleached with oxygen at a delignification degree of 40% or more, and then bleached with ozone at a pulp concentration of 25% or more. There is disclosed a method for producing a high brightness pulp for a light-sensitive material having excellent bleaching characteristics, which comprises performing multi-stage bleaching including chlorine dioxide bleaching (see Patent Document 13). However, in the high-brightness pulp obtained by the conventional method, a very small amount of a potential coloring substance which becomes deeper by heat or ultraviolet rays remains, and the whiteness decreases over time, so-called fading. It was difficult to avoid the phenomenon.
特許文献 10 :特開平 6— 101185号公報 Patent Document 10: JP-A-6-101185
特許文献 11 :特開平 9一 105091号公報 Patent Document 11: JP-A-9-1509509
特許文献 12 :特開 2002— 62622号公報
特許文献 13 :特開 2003— 41494号公報 Patent Document 12: JP-A-2002-62622 Patent Document 13: JP-A-2003-41494
発明の開示 Disclosure of the invention
発明が解決しょうとする課題 Problems to be solved by the invention
[0011] 本第 1発明の課題は、前述の様な、パルプの酸処理あるいは光照射技術を更に発 展させ、塩素系薬品を軽減し、かつ従来の漂白方法と比較してより効率的な漂白方 法を開発すること、及び光漂白前段に酸処理および通常の TCF漂白で使用される漂 白段を、また光漂白後段にアルカリ性過酸化水素漂白段を導入することで、光漂白 段の光照射時間を大幅に短縮し、最終 ISO白色度 84%以上とする TCF漂白法を開 究することにある。 [0011] The object of the first invention is to further develop the pulp acid treatment or light irradiation technique as described above, reduce chlorine-based chemicals, and achieve more efficient bleaching methods than conventional bleaching methods. By developing a bleaching method and introducing an acid treatment and a bleaching stage used in normal TCF bleaching before the photobleaching process and introducing an alkaline hydrogen peroxide bleaching stage after the photobleaching process, The aim is to develop a TCF bleaching method that significantly shortens the light irradiation time and achieves a final ISO brightness of 84% or more.
[0012] 本第 2発明の課題は、力、かる従来技術の欠点を克服し、環境負荷が少なくかつ退 色性のなレ、優れた高白色度パルプおよびそれを含有した紙を提供することにある。 課題を解決するための手段 [0012] An object of the second invention is to provide a pulp excellent in power and overcoming the disadvantages of the related art, which has a low environmental load and has fading, excellent high whiteness pulp, and paper containing the pulp. It is in. Means for solving the problem
[0013] 発明者らは、鋭意検討の結果、酸処理後洗浄したパルプをアルカリ性条件下、好ま しくは、 pHIO〜： 13の範囲で、波長 100〜400nmの紫外光及び/又は可視光を照 射することにより、非常に効率の良い非塩素系の漂白方法を見出し、本第 1発明の 1 に至ったものである。 [0013] As a result of intensive studies, the inventors found that the pulp washed after the acid treatment was irradiated with ultraviolet light and / or visible light having a wavelength of 100 to 400 nm under alkaline conditions, preferably, pHIO ~: 13. By irradiation, a very efficient non-chlorine bleaching method was found, which led to the first aspect of the present invention.
[0014] また、酸処理洗浄したパルプに対して、オゾンの存在下で波長 100〜400nmの紫 外光及び/又は可視光による照射処理することにより、非常に効率の良いパルプの 漂白方法を見出し、本第 1発明の 2に至ったものである。 [0014] Furthermore, a very efficient pulp bleaching method was found by subjecting acid-treated pulp to irradiation treatment with ultraviolet light and / or visible light having a wavelength of 100 to 400 nm in the presence of ozone. This leads to the second aspect of the first invention.
[0015] さらに、パルプの完全無塩素 (TCF)漂白において、酸素脱リグニン処理したパル プを酸処理後、通常の TCF漂白で使用される漂白方法により漂白したパルプを、ァ ルカリ性条件下で波長 100〜400nmの紫外光及び/又は可視光による光漂白処理 を行った後、アルカリ性過酸化水素漂白を行うことが、非常に効率の良い漂白方法 であることを見出したものである（本第 1発明の 3)。 [0015] In addition, in completely chlorine-free (TCF) bleaching of pulp, pulp that has been subjected to oxygen delignification treatment is acid-treated, and then pulp bleached by a bleaching method used in ordinary TCF bleaching is subjected to alkaline conditions. It has been found that performing a bleaching treatment with ultraviolet light and / or visible light having a wavelength of 100 to 400 nm and then performing an alkaline hydrogen peroxide bleaching is a very efficient bleaching method. 1) 3) of the invention.
さらにまた、このような高白色度で、かつ退色性の低いパルプとして、本発明者らは、 前記従来技術の難点を解消すべく鋭意検討を重ねた結果、漂白パルプをさらに紫 外光処理することで、上記のような白色度が高ぐ退色性がなぐかつ紙力の強いパ ルプの製造が可能であることを見出し、本第 2発明を完成するに至った。即ち、本第
2発明は、 ISO白色度が 88%以上であって、下記の退色試験： Furthermore, as a pulp having such a high whiteness and a low fading property, the present inventors have conducted intensive studies in order to solve the disadvantages of the above-mentioned conventional technology, and as a result, furthermore, the bleached pulp is further subjected to an ultraviolet light treatment. As a result, the present inventors have found that it is possible to produce a pulp having a high degree of whiteness, no fading, and a high paper strength, and completed the second invention. That is, (2) The invention has an ISO whiteness of 88% or more and the following fading test:
QIS P 8222に従って手抄き紙を作成し、 J. TAPPI No. 21 紙及び板紙—退 色度試験方法の B法（キセノンアークランプ式耐光性試験器による方法）に準じて 30 Hand-made paper was prepared in accordance with QIS P 8222, and was prepared according to J. TAPPI No. 21 Paper and paperboard-Discoloration test method B method (method using a xenon arc lamp type light resistance tester).
°Cの環境下で、光量 67WZm2のキセノンランプを 30分間照射した後、 ISO白色度を 測定し、処理前の ISO白色度との低下率を求める。 ) After irradiating a xenon lamp with a light intensity of 67 WZm 2 for 30 minutes in an environment of ° C, measure the ISO whiteness and calculate the rate of decrease from the ISO whiteness before processing. )
において白色度の低下率が 1.0%以下である高白色度化学パルプである。 It is a high brightness chemical pulp having a whiteness reduction rate of 1.0% or less.
図面の簡単な説明 Brief Description of Drawings
[0016] [図 1]本発明における照射反応装置を用いるシステムの一例を示す図である。 FIG. 1 is a diagram showing an example of a system using the irradiation reaction device according to the present invention.
[図 2]本発明で用いる内部照射型の照射反応装置を示す図である。 FIG. 2 is a view showing an internal irradiation type irradiation reaction apparatus used in the present invention.
[図 3]本発明実施例で用いた内部照射型の照射反応装置を示す図である。 FIG. 3 is a view showing an internal irradiation type irradiation reaction apparatus used in Examples of the present invention.
[図 4]L材パルプを用いた光照射処理における処理 pHと白色度の関係を示した図で ある。 FIG. 4 is a graph showing the relationship between treatment pH and whiteness in light irradiation treatment using L-wood pulp.
[図 5]L材パルプを用いた光照射処理における光照射時間と白色度の関係を示した 図である。 FIG. 5 is a view showing a relationship between light irradiation time and whiteness in light irradiation treatment using L-material pulp.
[図 6]N材パルプを用いた光照射処理における処理 pHと白色度の関係を示した図で ある。 FIG. 6 is a graph showing the relationship between treatment pH and whiteness in light irradiation treatment using N-material pulp.
[図 7]紫外光漂白実験装置の一例である。 FIG. 7 is an example of an ultraviolet light bleaching experiment apparatus.
符号の説明 Explanation of symbols
[0017] 10 :光照射原料調整タンク [0017] 10: Light irradiation raw material adjustment tank
11：光照射反応装置供給ポンプ 11: Light irradiation reactor supply pump
12 :光照射反応装置 12: Light irradiation reaction device
20 :光照射反応槽 20: Light irradiation reaction tank
21 :石英ガラス管 21: Quartz glass tube
22 :光照射光源 22: Light irradiation light source
23a, 23b :三方弁 23a, 23b: Three-way valve
24 :散気装置、散気管 24: diffuser, diffuser
25 :パルプスラリー入口 25: Pulp slurry inlet
26 :パルプスラリー出口
27 :攪拌機 26: Pulp slurry outlet 27: Stirrer
発明の実施の形態 Embodiment of the Invention
[0018] 本第 1発明についての発明の実施の形態を説明する。 An embodiment of the first invention will be described.
[0019] 本第 1発明の 1及び 2で対象とするパルプは、酸処理後洗浄したパルプである。特 に、クラフトパルプ (KP)に適用され、未晒 KPのみならず、酸素脱リグニン KP、ォゾ ン漂白 ΚΡ等にも好適である。本第 1発明の 3の漂白方法の対象となるパルプは、クラ フト蒸解を行い、酸素脱リグニン処理した化学パルプである。また、本第 1発明及び 第 2発明（ィ匕学パルプ)で使用するパルプ原料としては、特に限定するものではなぐ 広葉樹あるいは針葉樹の他、ケナフ、麻、イネ、パカス、竹等の植物でも良い。本第 1 発明の 2のパルプ漂白方法は、上記酸素脱リグニン処理したパルプを、酸処理後、 通常の TCF漂白で使用される漂白方法により漂白したパルプを、アルカリ性条件下 で波長 100〜400nmの紫外光及び/又は可視光による光照射処理を行った後、ァ ルカリ性過酸化水素漂白を行う。 The pulp targeted in 1 and 2 of the first invention is pulp washed after acid treatment. In particular, it is applied to kraft pulp (KP) and is suitable not only for unbleached KP, but also for oxygen delignification KP, ozon bleaching, etc. The pulp to be subjected to the bleaching method of the third aspect of the present invention is a chemical pulp which has been subjected to a craft digestion and subjected to an oxygen delignification treatment. The pulp raw material used in the first invention and the second invention (i-Danigaku pulp) is not particularly limited. In addition to hardwood or softwood, plants such as kenaf, hemp, rice, pacas, bamboo and the like may be used. . The pulp bleaching method of the second aspect of the present invention is characterized in that the pulp that has been subjected to the oxygen delignification treatment is acid-treated, and then bleached by a bleaching method used in ordinary TCF bleaching. After the light irradiation treatment with ultraviolet light and / or visible light, bleaching with alkaline hydrogen peroxide is performed.
[0020] 本発明の酸処理に使用する酸の種類は、無機酸でも有機酸でも良い。無機酸とし ては、硫酸、塩酸、硝酸、亜硫酸、亜硝酸、リン酸、二酸化塩素発生装置の残留酸な どの鉱酸を使用できる。好適には、硫酸である。有機酸としては、酢酸、乳酸、蓚酸、 クェン酸、蟻酸などを使用できる。酸処理時の pHは、 1. 0〜6. 0の範囲であり、好ま しく ίま 1. 0〜5. 0、更に好ましく ίま 2. 0〜5. 0、最適に fま 2. 5〜3. 5である。 pH力 1 . 0未満の場合はへキセンゥロン酸等と有害金属の除去は充分である力 酸が過剰 であるため粘度低下が大きくなる。一方、 pHが 6. 0を超えると酸濃度が低ぐへキセ ンゥロン酸等と有害金属の除去が不十分となる。へキセンゥロン酸の多い広葉樹パル プの場合、酸処理時の pHを 2. 5〜3. 5とすると、酸処理の温度を下げることが可能 であり、酸処理コストを低減できるという効果が生じてくる。 [0020] The type of acid used in the acid treatment of the present invention may be an inorganic acid or an organic acid. Mineral acids such as sulfuric acid, hydrochloric acid, nitric acid, sulfurous acid, nitrous acid, phosphoric acid, and residual acids from chlorine dioxide generators can be used as inorganic acids. Preferably, it is sulfuric acid. As the organic acid, acetic acid, lactic acid, oxalic acid, citric acid, formic acid, and the like can be used. The pH during the acid treatment is in the range of 1.0 to 6.0, preferably 1.0 to 5.0, more preferably 2.0 to 5.0, and optimally 2.5. ~ 3.5. When the pH is less than 1.0, hexeneduronic acid and other harmful metals are sufficiently removed. Since the acid is excessive, the viscosity decreases greatly. On the other hand, if the pH exceeds 6.0, the acid concentration will be low and the removal of hexenedulonic acid and other harmful metals will be insufficient. In the case of hardwood pulp containing a large amount of hexeneduronic acid, if the pH during acid treatment is set to 2.5 to 3.5, the temperature of acid treatment can be lowered, and the effect of reducing the acid treatment cost is produced. come.
[0021] 酸処理は大気圧下、加圧下のいずれでも実施可能であり、処理温度としては 80°C 〜180°C、好ましくは 80°C〜130°Cである。温度が 30°C以上 80°C未満では金属除 去の面では効果はあるが、へキセンゥロン酸等の除去効果がない。なお、 100°C未 満であれば耐圧性の反応容器を必要としないので設備コスト的に有利である。 [0021] The acid treatment can be carried out either under atmospheric pressure or under pressure, and the treatment temperature is from 80 ° C to 180 ° C, preferably from 80 ° C to 130 ° C. When the temperature is 30 ° C or higher and lower than 80 ° C, there is an effect in terms of metal removal, but there is no effect of removing hexeneduronic acid. If the temperature is lower than 100 ° C, a pressure-resistant reaction vessel is not required, which is advantageous in terms of equipment cost.
[0022] 酸処理時のパルプ濃度は、 0. ：!〜 50重量％の範囲であり、好ましくは 1. 0〜30重
量％、更に好ましくは 2. 0〜20重量％である。 [0022] The pulp concentration at the time of the acid treatment is in the range of 0 :! to 50% by weight, preferably 1.0 to 30% by weight. %, More preferably 2.0 to 20% by weight.
[0023] へキセンゥロン酸等と有害金属の除去効果は、酸処理時の pH、反応温度、および 反応時間で決定される。これより、反応時間は他の 2条件に合わせて適宜設定される 、反応温度 90°Cでの反応時間 1. 5〜6時間、反応温度 95°Cでの反応時間 50分 間〜 5時間、反応温度 100°Cでの反応時間 30分間〜 4. 5時間、反応温度 120〜： 13 0°Cでの反応時間 5〜50分間が典型とされている。 [0023] The effect of removing hexeneduronic acid and harmful metals is determined by the pH, reaction temperature, and reaction time during acid treatment. From this, the reaction time is appropriately set according to the other two conditions.The reaction time at a reaction temperature of 90 ° C is 1.5 to 6 hours, the reaction time at a reaction temperature of 95 ° C is 50 minutes to 5 hours, The reaction time at a reaction temperature of 100 ° C. is 30 minutes to 4.5 hours, and the reaction temperature is 120 to: The reaction time at 130 ° C. is 5 to 50 minutes.
[0024] また、酸性条件下で行われるオゾン漂白も、本願の対象とする酸処理の一形態で あり、通常の酸性オゾン漂白の条件が適用できる。ちなみに、一般的な酸性オゾン漂 白の条件は、オゾン濃度 1〜20重量％のオゾンガスを用いて、 pHl . 0〜8. 0 (本第 1発明の 1及び 3)又は ρΗ1〜7 (本第 1発明の 2)、パルプ濃度 0.：!〜 50重量％、温 度は 25〜95°C、が好適とされている。また、ここでの圧力についても負圧の状態から 加圧された状態まで特に限定されない。 [0024] Ozone bleaching performed under acidic conditions is also one form of the acid treatment targeted in the present application, and ordinary conditions for acidic ozone bleaching can be applied. By the way, the general acidic ozone bleaching conditions are as follows: ozone gas having an ozone concentration of 1 to 20% by weight, pH 1.0 to 8.0 (1 and 3 of the first invention) or ρΗ1 to 7 (this In 2) of the invention, the pulp concentration is preferably 0 :! to 50% by weight, and the temperature is preferably 25 to 95 ° C. Also, the pressure here is not particularly limited from a negative pressure state to a pressurized state.
[0025] なお、酸処理に際しては、 EDTA、 DPTA等のキレート剤を併用することにより、光 照射処理における更に大きな漂白反応促進効果が得られる。 [0025] In the acid treatment, by using a chelating agent such as EDTA or DPTA together, a greater bleaching reaction promoting effect in the light irradiation treatment can be obtained.
[0026] 酸処理の結果、その後の紫外光及び/又は可視光の光照射処理において漂白効 果が促進される理由は明白ではないが、パルプ中の残留リグニンと金属イオン、特に 鉄イオンとが金属錯体を形成し、これが光照射処理によって着色化する。従って、酸 処理によって金属イオンを除去することによって光照射処理による漂白効果が向上 すると推察される。 [0026] As a result of the acid treatment, it is not clear why the bleaching effect is promoted in the subsequent irradiation with ultraviolet light and / or visible light, but the residual lignin in the pulp and metal ions, particularly iron ions, are not removed. A metal complex is formed, which is colored by the light irradiation treatment. Therefore, it is presumed that the bleaching effect by the light irradiation treatment is improved by removing the metal ions by the acid treatment.
[0027] 本発明において、オゾンを含む酸処理の後に、処理パルプの脱水及び/又は洗 浄を行うが、これらはパルプ製造において公知の脱水機及び/又は洗浄機を用いる こと力 Sできる。また、洗浄には新水のほか、酸処理以降の漂白工程で発生する漂白 排水や抄紙工程力 発生する抄紙排水等を使用することができる。 In the present invention, dewatering and / or washing of the treated pulp is performed after the acid treatment including ozone, and these can be performed using a known dehydrator and / or washing machine in pulp production. For washing, in addition to fresh water, bleaching wastewater generated in the bleaching step after acid treatment or papermaking wastewater generated in the papermaking process can be used.
[0028] 本発明においては、前記酸処理したパルプに対して、アルカリ性条件下で、波長 1 00〜400nmの紫外光及び/又は可視光を照射する力 アルカリ性条件としては、 p Hとして 10〜： 13が好ましい。広葉樹パルプを処理とする場合には、 pH10〜12が、 また針葉樹パルプを処理とする場合には、 pHl l〜： 13が特に好ましい。本第 1発明 の 2においては、前記酸処理したパルプに対して、アルカリ性条件下あるいは酸性条
件下で、波長 100〜400nmの紫外光及び/又は可視光による照射処理を行う。ァ ルカリ性条件としては pH10〜13が、酸性条件としては pH2〜4の範囲が好ましい。 なお、この pH調整のために使用するアルカリとしては、通常のアルカリ性薬剤が使用 可能であるが、取扱い易さ等の点から水酸化ナトリウム、水酸化カリウム、珪酸ナトリウ ム、炭酸ナトリウムが、特に好ましい。 In the present invention, the acid-treated pulp is irradiated with ultraviolet light and / or visible light having a wavelength of 100 to 400 nm under alkaline conditions. As alkaline conditions, pH is 10 to: 13 is preferred. When hardwood pulp is treated, pH 10 to 12 is preferable, and when softwood pulp is treated, pH 11 to 13 is particularly preferable. In the second aspect of the first invention, the acid-treated pulp is treated under an alkaline condition or an acidic condition. Under the conditions, irradiation treatment with ultraviolet light and / or visible light having a wavelength of 100 to 400 nm is performed. The alkaline condition is preferably pH 10-13, and the acidic condition is preferably pH 2-4. As the alkali used for the pH adjustment, a normal alkaline agent can be used, but sodium hydroxide, potassium hydroxide, sodium silicate, and sodium carbonate are particularly preferable from the viewpoint of easy handling. .
[0029] 本発明の光照射処理時の、パルプ濃度は 0. 1〜： 12重量％が好ましレ、。 0. 1重量 %未満では漂白反応効率は高くなるものの、エネルギー効率が低下するため好まし くない。 12重量％を超える場合には、照射装置内でのパルプスラリ—の流動性が悪 くなるため、漂白反応効率が低下するため好ましくない。 [0029] The pulp concentration during the light irradiation treatment of the present invention is preferably from 0.1 to 12% by weight. When the content is less than 0.1% by weight, the efficiency of the bleaching reaction is increased, but the energy efficiency is lowered, which is not preferable. If the content exceeds 12% by weight, the fluidity of the pulp slurry in the irradiation device deteriorates, and the efficiency of the bleaching reaction decreases, which is not preferable.
[0030] また、この照射処理時の、パルプスラリーの温度は 20〜95°Cが好ましぐ 20°C未 満では漂白反応効率が低ぐまた一方、 95°Cを超える場合には、パルプ品質悪化の 可能性がでてくることや、あるいは反応装置内圧力が大気圧を超える可能性がでてく るため、耐圧性を考慮した装置設計が必要となるなど点で、いずれも好ましくない。 [0030] In addition, the temperature of the pulp slurry during this irradiation treatment is preferably 20 to 95 ° C. If the temperature is less than 20 ° C, the bleaching reaction efficiency is low. This is not preferable in that there is a possibility that the quality will deteriorate, or the pressure in the reactor will exceed the atmospheric pressure, so that it is necessary to design the device in consideration of the pressure resistance.
[0031] 本発明の照射装置において、照射する光の波長としては、 100〜400nmの波長が 好ましいが、 200〜360nm (本第 1発明の 2では、 180〜360nm)の波長力 S特に好 ましい。 lOOnm未満の波長では、セルロースの光分解が促進されるためパルプ強度 が著しく低下し、また 400nmを超える波長では、光着色物質の光励起が不十分であ るため光漂白性が大幅に低下するので、レ、ずれも好ましくなレ、。 [0031] In the irradiation device of the present invention, the wavelength of the light to be irradiated is preferably 100 to 400 nm, but is preferably 200 to 360 nm (180 to 360 nm in 2 of the first invention). No. If the wavelength is less than 100 nm, the photolysis of cellulose is accelerated, resulting in a significant decrease in pulp strength.If the wavelength is greater than 400 nm, the photobleaching properties are significantly reduced due to insufficient photoexcitation of the photo-colored substance. , 、, the deviation is also preferable.
[0032] 照射する光源としては、 100〜400nmの波長領域の光を持つものが使用でき、具 体的には、キセノンショートアークランプ、超高圧水銀ランプ、高圧水銀ランプ、低圧 水銀ランプ、重水素ランプ、メタルハライドランプ等〔木下忍「UV照射装置」、接着（2 002年、 46卷 7号) P20〜27、あるいは杉森彰「光化学 第 8章光化学の実験方法 I」 、（裳華房、 1998年発行） pi 26〜： 136、参照〕がー例として挙げられ、これらの 1種あ るいは 2種以上を任意に組合せて使用することができる。 [0032] As a light source for irradiation, a light source having light in a wavelength region of 100 to 400 nm can be used. Specifically, a xenon short arc lamp, an ultra-high pressure mercury lamp, a high pressure mercury lamp, a low pressure mercury lamp, a deuterium lamp, a metal halide lamp, etc. [Nin Kinoshita "UV irradiation apparatus", the adhesive (2 002 years, 46 Certificates No. 7) P 20 to 27, or Akira Sugimori "photochemical experimental method I Chapter 8 photochemical" (Mohanabo, (Issued in 1998) pi 26 ~: 136, see], and these may be used alone or in any combination of two or more.
[0033] また、照射反応装置においてパルプが受ける照射の程度は、照射反応装置内での パルプの滞留時間を調節することや、照射光源のエネルギー量を調節すること等に より、任意に設定できる。照射反応装置内でのパルプの滞留時間調節の具体的な一 例を挙げれば、照射装置内のパルプ濃度を水希釈によって調節することや、あるい
は空気や窒素等の不活性気体をパルプスラリー中に吹き込むことによってパルプ濃 度を調節することなどである。これらの条件は、 目標とする光照射反応後のパルプ品 質（白色度等）にあわせて、適宜設定できる。 [0033] The degree of irradiation of the pulp in the irradiation reactor can be arbitrarily set by adjusting the residence time of the pulp in the irradiation reactor, adjusting the energy amount of the irradiation light source, or the like. . As a specific example of the control of the pulp residence time in the irradiation reactor, the pulp concentration in the irradiation device may be adjusted by dilution with water, or may be adjusted. Is to adjust the pulp concentration by blowing an inert gas such as air or nitrogen into the pulp slurry. These conditions can be appropriately set according to the target pulp quality (whiteness etc.) after the light irradiation reaction.
[0034] 本第 1発明の 2は、前記の波長 100〜400nmの紫外光及び/又は可視光による 照射処理をオゾンの存在下で行うことが特徴である。また、 135〜242nmの波長領 域の光を照射する場合、光源周辺の気層部には通常空気が存在するためオゾンが 生成する。本発明においては、この光源周辺部に連続的に空気を供給する一方で、 生成するオゾンを連続的に抜き出し、光照射原料に注入することにより、系外からォ ゾンを供給すること無しに、反応の助剤としてオゾンを利用することができる。また更 に、光源周辺の気層部に酸素を供給することにより更に大量のオゾンを得ることがで きる。もちろん、発生したオゾンは、光照射反応時の助剤としてだけでなぐ通常のォ ゾン漂白にも使用できる。このように、本発明では、光照射反応装置で副次的に発生 するオゾンを利用できることも大きな利点である。なお、このような空気や酸素を、光 源周辺部でなぐ被処理パルプに供給することによつてもオゾンの生成は可能である 。更に、このような紫外光の作用によらない方法で系外から得たオゾンを反応の助剤 として利用することも可能である。 [0034] The second aspect of the first invention is characterized in that the irradiation treatment with ultraviolet light and / or visible light having a wavelength of 100 to 400 nm is performed in the presence of ozone. When irradiating light in the wavelength range of 135 to 242 nm, ozone is generated because air usually exists in the gas layer around the light source. In the present invention, while continuously supplying air to the periphery of the light source, the ozone generated is continuously extracted and injected into the light irradiation material, so that ozone is not supplied from outside the system. Ozone can be used as a reaction aid. Further, by supplying oxygen to the gas layer around the light source, a larger amount of ozone can be obtained. Of course, the generated ozone can be used for ordinary ozone bleaching, not only as an aid during the light irradiation reaction. As described above, in the present invention, it is also a great advantage that ozone generated as a by-product in the light irradiation reaction device can be used. Ozone can also be generated by supplying such air or oxygen to the pulp to be treated around the light source. Further, it is also possible to use ozone obtained from outside the system by a method not depending on the action of ultraviolet light as a reaction aid.
[0035] このように光照射反応装置で副次的に発生するオゾンの濃度は、空気や酸素の供 給の方法や酸素の濃度にもよるが、 0. 5〜100ppmである。このような低濃度のォゾ ンであっても、光照射処理との組み合わせでは非常に高い漂白効率が得られること は本第 1発明の 2の大きな特徴である。 [0035] As described above, the concentration of ozone generated as a by-product in the light irradiation reaction device is 0.5 to 100 ppm, depending on the method of supplying air or oxygen and the concentration of oxygen. It is a major feature of the first invention 2 that even with such a low concentration of ozone, extremely high bleaching efficiency can be obtained in combination with light irradiation treatment.
[0036] この考え方を更に積極的に応用して、光照射反応装置に用いる光源を、波長 100 〜400nmに特性波長領域を持ち、かつ特性波長の異なる光源のうちから複数を選 定して用いることができる。具体的には、オゾン発生効率の高い 135〜242nmの狭 い波長特性を持つ光源と、光照射反応に適した 100〜400nmの波長領域をまんベ んなく持つ光源との組合せ等であり、これにより更に高い漂白効率を得ることができる [0036] Applying this idea more positively, a plurality of light sources having a characteristic wavelength range of 100 to 400 nm and having different characteristic wavelengths are selected and used as light sources for a light irradiation reaction device. be able to. Specifically, a combination of a light source with high ozone generation efficiency with a narrow wavelength characteristic of 135 to 242 nm and a light source with a complete wavelength range of 100 to 400 nm suitable for light irradiation reaction is used. Higher bleaching efficiency
[0037] また、本発明の光照射処理においては、助剤として、還元剤（例えば、 NaBH、ヒド ラジン、水素）、酸化剤（例えば、酸素、オゾン）、過酸化物（例えば、過酸化水素、過
酢酸、過炭酸 Na、過ホウ酸 Na)、水素供与性有機化合物（例えば、アルコール、鎖 状ァミンとして、ェチルァミン、ジェチルァミン、また環状ァミンとして、テトラメチルピ ペリジン）、ァセチル基を有する有機化合物（例えば、 α —ァセチルー γーブチロラ タトン、ァセトール、アセトン）を併用して、照射反応効率を高めることができる。 In the light irradiation treatment of the present invention, reducing agents (eg, NaBH, hydrazine, hydrogen), oxidizing agents (eg, oxygen, ozone), peroxides (eg, hydrogen peroxide) , Over Acetic acid, sodium percarbonate, sodium perborate), hydrogen-donating organic compounds (for example, alcohol, linear amines such as ethylamine and getylamine, and cyclic amines as tetramethylpiperidine), and organic compounds having an acetyl group (for example, α —Acetyl-γ-butyrolataton, acetol, acetone) can increase the irradiation reaction efficiency.
[0038] 本第 1発明の 3においては、光漂白前段で ISO白色度を 70〜75%とするのに使用 される TCF漂白としてオゾン漂白、過酸化水素漂白等を単独または併用して使用で きる。 [0038] In the third aspect of the first invention, ozone bleaching, hydrogen peroxide bleaching, or the like may be used alone or in combination as TCF bleaching used to bring the ISO whiteness to 70 to 75% in the pre-bleaching stage. Wear.
[0039] 本第 1発明の 3においてはオゾン漂白は、通常のオゾン漂白の条件が適用できる。 [0039] In the third aspect of the first invention, ozone bleaching can be performed under ordinary ozone bleaching conditions.
すなわち、オゾン漂白の条件は、オゾン濃度 1〜20重量％のオゾンガスを用いて、 p Hl〜8、パルプ濃度 0· 1〜50重量％、温度 25〜95°C、の範囲で処理すればよい。ま た、オゾン漂白時の圧力については負圧の状態から加圧された状態まで特に限定さ れない。 That is, the ozone bleaching conditions may be such that ozone gas having an ozone concentration of 1 to 20% by weight is used, and the treatment is performed in the range of pH 8 to 0.1, pulp concentration of 0.1 to 50% by weight, and temperature of 25 to 95 ° C. . Further, the pressure at the time of ozone bleaching is not particularly limited from a negative pressure state to a pressurized state.
[0040] 本第 1発明の 3においては過酸化水素漂白は、通常のアルカリ性過酸化水素漂白 の条件が適用できる。すなわち、アルカリ性過酸化水素漂白は、過酸化水素の添カロ 率が対パルプ0.1〜2.0重量％、 ρΗ11〜13、パルプ濃度 0.1〜50重量％、温度 50〜9 5°C、の範囲で処理すればよい。 [0040] In the third aspect of the first invention, hydrogen peroxide bleaching can be performed under ordinary alkaline hydrogen peroxide bleaching conditions. In other words, alkaline hydrogen peroxide bleaching is performed when the hydrogen peroxide is added in the range of 0.1 to 2.0% by weight of pulp, ρ 濃度 11 to 13, pulp concentration of 0.1 to 50% by weight, and temperature of 50 to 95 ° C. Just fine.
[0041] 本第 1発明の 3においては、酸処理後、通常の TCF漂白によって ISO白色度を 70 〜75%まで予め向上させておくことで、光漂白処理時間を大幅に短縮できる結果、 光漂白に要する電力費を大幅に削減できる。さらに、光漂白により白色度を 5%以上 向上させることで ISO白色度を 75〜80%にした後、最終漂白段で過酸化水素漂白を 行うと、過酸化水素漂白反応が促進されるため、効率良く ISO白色度 84%以上のパ ルプが得られる。光漂白前の TCF漂白で白色度を 75%より高くするには、薬品添カロ 量を増やしつつ厳しい反応条件（高温、長時間）で処理する必要があり、漂白コストと パルプ品質の観点から好ましくなレ、。一方、光漂白前の ISO白色度が 80%より高いと 、パルプ中に含まれる着色成分が極微量となり、光漂白の反応効率が顕著に悪化す る。従って、漂白コストの観点から、光漂白ではなぐ過酸化水素漂白で白色度を向 上させるのは好ましい。 TCF漂白後の白色度が 70%より低い場合、パルプ中に含ま れる着色成分が多いため、最終白色度を 84%以上にするには、光漂白処理時間を
長くする必要があり、電力費増を招く。また、光漂白後の白色度が 75%より低い場合 、パルプ中に比較的多く残存する難漂白性着色成分のため、過酸化水素漂白のみ で最終白色度 84%以上にするとは困難である。 [0041] In the third aspect of the first invention, after the acid treatment, the ISO bleaching degree is previously improved to 70 to 75% by ordinary TCF bleaching, so that the light bleaching processing time can be significantly shortened. Power costs for bleaching can be significantly reduced. Furthermore, if the whiteness is improved by 5% or more by light bleaching to bring the ISO whiteness to 75 to 80%, and then hydrogen peroxide bleaching is performed in the final bleaching stage, the hydrogen peroxide bleaching reaction is accelerated. A pulp with an ISO brightness of 84% or more can be obtained efficiently. In order to increase the whiteness to more than 75% by TCF bleaching before light bleaching, it is necessary to increase the amount of added chemicals and to process under severe reaction conditions (high temperature, long time), which is preferable from the viewpoint of bleaching cost and pulp quality. What? On the other hand, if the ISO whiteness before light bleaching is higher than 80%, the coloring components contained in the pulp are extremely small, and the reaction efficiency of light bleaching is remarkably deteriorated. Therefore, from the viewpoint of bleaching cost, it is preferable to improve the whiteness by hydrogen peroxide bleaching instead of light bleaching. If the whiteness after TCF bleaching is lower than 70%, the pulp contains many coloring components. It needs to be long, which leads to an increase in power costs. When the whiteness after light bleaching is lower than 75%, it is difficult to achieve a final whiteness of 84% or more by bleaching with hydrogen peroxide alone because of the relatively unbleachable coloring components remaining in the pulp.
[0042] 本発明における光照射反応装置を用いるシステムの一例を、図 1に示す。 FIG. 1 shows an example of a system using the light irradiation reaction device according to the present invention.
[0043] 酸処理されたパルプは、光照射原料調整タンク（10)に受け入れられ、ここで撹拌さ れながら、光照射反応に適した温度 ·ρΗ·パルプ濃度に調整される。調整された光 照射原料 1は、光照射反応装置供給ポンプ（11)により、光照射反応装置（12)に送 られる。必要により、その前に、薬液として光照射反応における還元剤等の助剤が添 カロされる。なお、この助剤の添加場所としては、図 1の薬液添加場所の他、光照射原 料調整タンク（10)、あるいは両方であっても良ぐ助剤の性質あるいは光照射反応 条件にあわせて任意に設定できるが、迅速に反応する助剤あるいはそれ自体分解 性の高い助剤については、できるだけ光照射反応装置（12)に入る直前、すなわち 図 1の薬液添加場所に添加することが好ましい。 [0043] The acid-treated pulp is received in the light irradiation raw material adjustment tank (10), and is adjusted to a temperature · ρ · · pulp concentration suitable for the light irradiation reaction while being stirred. The adjusted light irradiation raw material 1 is sent to the light irradiation reaction device (12) by the light irradiation reaction device supply pump (11). If necessary, an auxiliary agent such as a reducing agent in the light irradiation reaction is added as a chemical before that. In addition to the location of the chemical solution shown in Fig. 1, the auxiliary agent may be added to the light irradiation material adjustment tank (10), or both, depending on the properties of the auxiliary agent or the light irradiation reaction conditions. Although it can be set arbitrarily, it is preferable to add a quick-reacting auxiliary or an auxiliary having high decomposability by itself as soon as possible into the light irradiation reaction device (12), that is, at the chemical solution addition site in FIG.
[0044] また、必要に応じて、光照射反応装置（12)に入る前に、気体を供給することができ る。これにより、光照射反応装置（12)内でのパルプ濃度（この場合、気体の密度が 小さいので、容量％として考慮）の調整が可能となるため、光照射反応装置（12)内 でのパルプの滞留時間あるいは照射反応時間を任意に調整できる。なお、この場合 に用いる気体の種類としては、空気あるいは窒素等の不活性気体が好適であり、こ れらを微細気泡としてパルプスラリー中に分散して用いる。また、光反応の助剤のうち 、水素、酸素、オゾン等の気体を用いる場合にも、同様に図 Εの場所に供給すること ができる。 [0044] Further, if necessary, a gas can be supplied before entering the light irradiation reaction device (12). This makes it possible to adjust the pulp concentration in the light irradiation reactor (12) (in this case, the gas density is small, so it is considered as volume%), so that the pulp in the light irradiation reactor (12) can be adjusted. The residence time or irradiation reaction time can be arbitrarily adjusted. In addition, as a kind of gas used in this case, an inert gas such as air or nitrogen is suitable, and these are used as fine bubbles dispersed in a pulp slurry. Also, when a gas such as hydrogen, oxygen, or ozone is used among the photoreaction aids, it can be similarly supplied to the location shown in FIG.
[0045] 次に、光照射反応装置（12)を出た光照射反応後のパルプは、 目標とするパルプ 品質が得られたものについては、光照射反応を終了し次工程へ送る（C1 : 光照射 反応後のパルプ 1)。また、一方目標とするパルプ品質が得られなかったものについ ては、光照射反応を繰返すため再循環する（C2 :光照射反応後のパルプ 2)。この、 C1と C2の比率に関しては、 目標とするパルプ品質に対応させて、任意に設定するこ とができる。 Next, as for the pulp after the light irradiation reaction that has exited the light irradiation reaction device (12), the pulp having the target pulp quality is finished and sent to the next step (C1: Pulp after light irradiation reaction 1). On the other hand, if the target pulp quality is not obtained, the pulp is recycled to repeat the light irradiation reaction (C2: Pulp after light irradiation reaction). The ratio of C1 and C2 can be set arbitrarily according to the target pulp quality.
[0046] なお、照射反応装置については、基本的には照射光源部とパルプスラリー容器部
から構成され、照射光源部がパルプスラリー容器部の内部に存在する内部照射型と 、照射光源部がパルプスラリー容器部の外部に存在する外部照射型とがあるが〔杉 森彰「光化学 第 8章光化学の実験方法 I」、（裳華房、 1998年発行) pl 26〜： 136、 参照〕、本発明においては、特に限定されない。また、照射光源部からの光がパルプ スラリーに照射されるが、通常、光源部周辺には空気等の気体が存在するため隔壁 が必要である。その際、光エネルギーが減衰することなく隔壁を透過するために、隔 壁材質の選定が重要である。 The irradiation reactor is basically composed of an irradiation light source unit and a pulp slurry container unit. There are an internal irradiation type in which the irradiation light source is present inside the pulp slurry container, and an external irradiation type in which the irradiation light source is present outside the pulp slurry container [Akira Sugimori “Photochemical No. 8 Chapter Photochemical Experiment Method I "(issued by Shokabo, 1998), pl 26-: 136), and are not particularly limited in the present invention. In addition, light from the irradiation light source unit is irradiated on the pulp slurry. Usually, a gas such as air exists around the light source unit, and a partition wall is required. At that time, it is important to select the material of the partition wall so that the light energy passes through the partition wall without attenuation.
[0047] 本発明において、例えば、 300nmより長波長の光を用いる場合は、硬質ガラス製 のものを用いることができるが、 254nmより短波長の光を用いる場合は、石英ガラス 製のものを用いる。なお、このパルプスラリー容器の光透過反応に関与しない部分の 材質については、用いる光の波長に対して劣化の少ない材質の中から適切なものを 選定すること力 Sできる。 In the present invention, for example, when light having a wavelength longer than 300 nm is used, hard glass can be used. When light having a wavelength shorter than 254 nm is used, quartz glass can be used. . As for the material of the portion of the pulp slurry container that does not participate in the light transmission reaction, it is possible to select an appropriate material from materials having little deterioration with respect to the wavelength of light used.
[0048] 光照射反応装置の一例を図 2に示す。酸処理されたパルプを光照射反応に適した 温度 · ρΗ ·パルプ濃度に調整し、更に必要により還元剤等の助剤を添加した後、スラ リー（al)として、この反応層（20)に（25)より注入される。注入されたパルプスラリー は、装置（20)内で流動しながら、光照射光源（22)で発生し隔壁（21 :石英ガラス管 )を通過した光による照射反応を行った後、装置出口（26)力 排出される。 FIG. 2 shows an example of the light irradiation reaction device. The acid-treated pulp is adjusted to a temperature · ρΗ · pulp concentration suitable for the light irradiation reaction, and if necessary, an auxiliary agent such as a reducing agent is added. Then, a slurry (al) is added to this reaction layer (20). Injected from (25). The injected pulp slurry flows in the apparatus (20), and is subjected to an irradiation reaction by light generated by the light irradiation light source (22) and passed through the partition (21: quartz glass tube). ) Power is discharged.
[0049] また、必要に応じて、光照射反応装置（20)に付設される散気装置（24)を通じて、 気体を供給することができる。これにより、光照射反応装置（20)内でのパルプ濃度（ この場合、気体の密度が小さいので、容量％として考慮）の調整が可能となるため、 光照射反応装置（20)内でのパルプの滞留時間あるいは照射反応時間を任意に調 整できる。なお、この目的で用いる気体の種類としては、空気あるいは窒素等の不活 性気体が好適であり、これらを微細気泡としてパルプスラリー中に分散して用いる。 [0049] Further, if necessary, a gas can be supplied through an air diffuser (24) attached to the light irradiation reaction device (20). This makes it possible to adjust the pulp concentration in the light irradiation reactor (20) (in this case, the gas density is small, so it is considered as volume%), and the pulp in the light irradiation reactor (20) can be adjusted. Residence time or irradiation reaction time can be adjusted arbitrarily. In addition, as a kind of gas used for this purpose, an inert gas such as air or nitrogen is suitable, and these are used as fine bubbles dispersed in a pulp slurry.
[0050] 一方、光反応の助剤のうち、水素、酸素、オゾン等の気体を用いる場合にも、この 散気装置（24)を通じて、気体を供給することができる。 [0050] On the other hand, when a gas such as hydrogen, oxygen, or ozone is used among the photoreaction aids, the gas can be supplied through the air diffuser (24).
[0051] また、図 2に示す様に、光照射光源として 135〜242nmの波長領域の光を用い、 光源冷却用気体 (bl)として、空気あるいは酸素を注入した場合、光照射部から排出 される気体中にはオゾンが存在する。このオゾンを含む排出ガスは、散気装置（24)
を通じて光照射反応装置（20)内のパルプスラリー中に注入することにより、系外から オゾンを供給すること無しに、反応の助剤としてオゾンを利用することができる。また、 発生したオゾンは、光照射反応時の助剤以外の通常のオゾン漂白にも使用できる。 また水素、酸素、オゾン等の光照射反応の助剤として効果のある気体を系外から注 入し、併用することもできる。これら気体の利用に関しては、三方弁（23a、 23b)を付 設することにより任意に設定できる。 As shown in FIG. 2, when light in the wavelength range of 135 to 242 nm is used as the light irradiation light source and air or oxygen is injected as the light source cooling gas (bl), the light is emitted from the light irradiation part. Ozone is present in these gases. The exhaust gas containing this ozone is supplied to a diffuser (24) Ozone can be used as a reaction aid without injecting ozone from outside the system by injecting it into the pulp slurry in the light irradiation reaction device (20). The generated ozone can also be used for ordinary ozone bleaching other than the aid during the light irradiation reaction. In addition, a gas effective as an aid for the light irradiation reaction, such as hydrogen, oxygen, and ozone, can be injected from the outside of the system and used together. Use of these gases can be arbitrarily set by installing three-way valves (23a, 23b).
[0052] なお、光照射反応装置において、温度 ·ρΗの調節装置、ガス濃度検出装置等の付 帯設備を必要に応じて任意に付設することができる。 [0052] In the light irradiation reaction device, auxiliary equipment such as a temperature / ρΗ control device and a gas concentration detection device can be arbitrarily provided as necessary.
[0053] また、本発明の光照射処理は 1回以上複数回繰り返すことができるが、これは漂白 効率や目標とするパルプ品質（白色度）、あるいは組合せる他の漂白方法との関係 等の状況にあわせて適宜設定できる。光照射処理は 1回以上複数回繰り返す例は、 (1)図 1における光照射装置を 2個以上設けることができる。この場合には、シリーズ であっても、パラレルであってもよい。 （2)図 1における光照射装置の中に照射光源を 複数個（特性の同じものでも、異なるものでもよい）設けることができる。 （3)図 1に示さ れるシステム内を再循環することができる。 [0053] The light irradiation treatment of the present invention can be repeated one or more times, and this includes the bleaching efficiency, the target pulp quality (whiteness), and the relationship with other bleaching methods to be combined. It can be set appropriately according to the situation. The example in which the light irradiation process is repeated once or more times is as follows. (1) Two or more light irradiation devices in FIG. 1 can be provided. In this case, it may be a series or a parallel. (2) A plurality of irradiation light sources (having the same or different characteristics) can be provided in the light irradiation device in FIG. (3) It can be recirculated in the system shown in Fig. 1.
[0054] 本発明の漂白方法は、塩素系、非塩素系を問わず他の全ての公知の漂白方法と 任意に組合せることができる。具体的には、他の漂白方法に続いて本発明の漂白方 法とする、あるいは、本発明の漂白方法に続いて他の漂白方法とすることができる。 特に、本発明の漂白を行った後、過酸化水素処理をすることが、好ましい。また、これ らのシーケンスを複数回繰り返すこともでき、その際、異なる漂白方法のと間に洗浄 段を設けることもできる。また、光照射システムを組み込んだ漂白シーケンスを複数回 繰り返すこともできる。なお、光照射処理を複数行う際には、光照射処理後に、洗浄 を行うことが好ましい。 [0054] The bleaching method of the present invention can be arbitrarily combined with all other known bleaching methods, whether chlorine-based or non-chlorine-based. Specifically, the bleaching method of the present invention can be followed by another bleaching method, or another bleaching method can be followed by the bleaching method of the present invention. In particular, it is preferable to perform a hydrogen peroxide treatment after performing the bleaching of the present invention. These sequences can also be repeated multiple times, with washing steps between different bleaching methods. In addition, the bleaching sequence incorporating the light irradiation system can be repeated several times. Note that when performing a plurality of light irradiation treatments, it is preferable to perform cleaning after the light irradiation treatments.
[0055] 本第 2発明についての発明の実施の形態を説明する。 An embodiment of the second invention will be described.
本発明は、 ISO白色度が 88%以上であって、下記の退色試験において白色度の低 下率が 1.0%以下である高白色度化学パルプである。すなわち、従来紙の退色性を 評価する際には熱による退色試験で評価することが一般的であつたが、本発明者ら の検討によれば、下記のような紫外光による退色試験で評価することが実際の紙の
退色性とよく相関することが判明した。 The present invention is a high-brightness chemical pulp having an ISO whiteness of 88% or more and a decrease in whiteness of 1.0% or less in a fading test described below. That is, when evaluating the fading property of conventional paper, it was common to evaluate by a fading test by heat, but according to the study of the present inventors, it was evaluated by the following fading test by ultraviolet light. Can do real paper It was found that it correlated well with fading.
[0056] JIS P8222に従って手抄き紙を作成し、 J. TAPPI No. 21 紙及び板紙 退色 度試験方法の B法（キセノンアークランプ式耐光性試験器による方法）に準じて 30°C の環境下で、光量 67WZm2のキセノンランプを 30分間照射した後、 JIS P 8148に 従って ISO白色度を測定し、処理前の ISO白色度との低下率を求める。本発明に使 用される化学パルプを得るための蒸解法としては、クラフト蒸解、ポリサルファイド蒸 解、ソーダ蒸解、アルカリサルファイト蒸解等の公知の蒸解法を用いることができるが[0056] Hand-made paper was prepared in accordance with JIS P8222, and the temperature was adjusted to 30 ° C in accordance with J. TAPPI No. 21 Paper and paperboard in accordance with Method B of the fading test method (method using a xenon arc lamp type light resistance tester). After irradiating a xenon lamp with a light intensity of 67 WZm 2 for 30 minutes below, measure the ISO whiteness according to JIS P8148, and determine the rate of decrease from the ISO whiteness before processing. As the cooking method for obtaining the chemical pulp used in the present invention, known cooking methods such as kraft cooking, polysulfide cooking, soda cooking, and alkali sulphite cooking can be used.
、パルプ品質、エネルギー効率を考慮すると、クラフト蒸解法が好適である。さらにク ラフト蒸解法としては修正蒸解法として、 MCC、 EMCC、 ITC、 Lo_ solids法等が 知られているが、特に限定することなく本発明に適用できる。木材は公知の条件でク ラフト蒸解することができるが、例えば、次の条件を挙げることができる。蒸解液の硫 化度は 7〜75%、好ましくは 15〜45%、有効アルカリ添加率は絶乾木材重量当り 5〜 30重量％、好ましくは 10〜25重量％、蒸解温度は 140〜170°Cである。また、蒸解方 式は、連続蒸解法或いはバッチ蒸解法のどちらでもよぐまた蒸解装置の方式は特 に問わない。 Considering the pulp quality and energy efficiency, the kraft cooking method is preferred. Further, as the modified cooking method, MCC, EMCC, ITC, Lo-solids method and the like are known as the cooking method, but can be applied to the present invention without particular limitation. Wood can be cooked under known conditions, for example, under the following conditions. The degree of sulfurization of the cooking liquor is 7 to 75%, preferably 15 to 45%, the effective alkali addition rate is 5 to 30% by weight, preferably 10 to 25% by weight, and the cooking temperature is 140 to 170 °. C. The cooking method may be either a continuous cooking method or a batch cooking method, and the method of the cooking apparatus is not particularly limited.
[0057] 本発明で使用する化学パルプは、公知の蒸解法により得られた未漂白化学パルプ を洗浄、粗選および精選工程を経て、酸素脱リグニン処理される。酸素脱リグニンの 条件は公知の方法で行うことができる。広葉樹化学パルプの場合、酸素脱リグニン後 のカッパ一価は 5〜15の範囲が良ぐ好ましくは？〜 15、さらに好ましくは 8〜12である 。この酸素脱リグニン処理は公知の中濃度法或いは高濃度法で実施される。例えば 、中濃度法の一般的な反応条件としては、パルプ固形分濃度 10〜18重量％、温度 1 00〜110°C、反応時間 60〜120分間、反応器内圧力 3〜6kgZm2が挙げられ、水酸 化ナトリウム添加率および酸素添加率は目標とするカッパ一価によって調整される。 [0057] The chemical pulp used in the present invention is subjected to an oxygen delignification treatment through an unbleached chemical pulp obtained by a known digestion method, followed by washing, rough selection and fine selection steps. The conditions for oxygen delignification can be performed by a known method. For hardwood chemical pulp, the kappa monovalent after oxygen delignification is preferably in the range of 5 to 15, preferably? ~ 15, more preferably 8 ~ 12. This oxygen delignification treatment is carried out by a known medium concentration method or high concentration method. For example, typical reaction conditions for the medium concentration method include a pulp solid concentration of 10 to 18% by weight, a temperature of 100 to 110 ° C, a reaction time of 60 to 120 minutes, and a reactor internal pressure of 3 to 6 kgZm 2. The sodium hydroxide addition rate and oxygen addition rate are adjusted according to the target kappa monovalent.
[0058] 本発明の高白色度化学パルプの製造において、酸素脱リグニン処理後のパルプを 引き続き酸処理を行ったものを使用することが好ましい。パルプの酸処理に使用する 酸の種類は、無機酸でも有機酸でも良レ、。無機酸としては、硫酸、塩酸、硝酸、亜硫 酸、亜硝酸、リン酸、二酸化塩素発生装置の残留酸等の鉱酸を使用できる。好適に は硫酸である。有機酸としては、酢酸、乳酸、蓚酸、クェン酸、ギ酸等を使用できる。
広葉樹パルプの酸処理時の pHは 1.5〜6.0の範囲であることが望ましぐ好ましくは 1. 0〜5.0、さらに好ましくは 2.0〜5.0、最適には 2.5〜3.5である。 pH力 1.0未満の場合は へキセンゥロン酸と金属イオンの除去は十分である力 酸が過剰のためパルプ粘度 が大幅に低下する。一方、 pHが 6.0を超えると酸濃度が低ぐへキセンゥロン酸と金 属イオンの除去が不充分となる。広葉樹化学パルプの場合、酸処理時の pHを 2.5〜 3.5とすると、酸処理時の温度を低下させることが可能であり、酸処理コストを低減でき るという効果が生じてくる。 [0058] In the production of the high brightness chemical pulp of the present invention, it is preferable to use pulp that has been subjected to an acid treatment after the oxygen delignification treatment. The type of acid used for acid treatment of pulp can be either inorganic or organic. As the inorganic acid, mineral acids such as sulfuric acid, hydrochloric acid, nitric acid, sulfurous acid, nitrous acid, phosphoric acid, and residual acid of a chlorine dioxide generator can be used. Preferably it is sulfuric acid. As the organic acid, acetic acid, lactic acid, oxalic acid, citric acid, formic acid and the like can be used. The pH of the hardwood pulp during acid treatment is desirably in the range of 1.5 to 6.0, preferably 1.0 to 5.0, more preferably 2.0 to 5.0, and most preferably 2.5 to 3.5. If the pH is less than 1.0, hexeneduronic acid and metal ions are sufficiently removed. Excessive acid reduces the pulp viscosity significantly. On the other hand, if the pH exceeds 6.0, the acid concentration is too low to remove hexeneduronic acid and metal ions insufficiently. In the case of hardwood chemical pulp, if the pH at the time of acid treatment is 2.5 to 3.5, the temperature at the time of acid treatment can be lowered, which has the effect of reducing the acid treatment cost.
[0059] 酸処理は大気圧下、加圧下のいずれでも実施可能である。例えば、大気圧下の酸 処理時の反応温度は 80°C以上 100°C未満の範囲である。好ましくは 80〜95°C、さら に好ましくは 80〜90°Cである。温度が 30°C以上 80°C未満では金属除去の面では効 果があるが、へキセンゥロン酸の除去効果がない。 [0059] The acid treatment can be performed either under atmospheric pressure or under pressure. For example, the reaction temperature during acid treatment at atmospheric pressure is in the range of 80 ° C or higher and less than 100 ° C. Preferably it is 80-95 ° C, more preferably 80-90 ° C. When the temperature is 30 ° C or higher and lower than 80 ° C, it is effective in removing metals, but there is no effect of removing hexeneduronic acid.
[0060] 酸処理後、パルプは引き続き多段漂白工程で漂白される。使用される薬品としては 、原子状塩素 (C)、苛性ソーダ (E)、次亜塩素酸塩 (H)、二酸化塩素 (D)、酸素 (〇 )、過酸化水素（P)、オゾン (Z)、硫酸 (A)、有機過酸等の公知の漂白剤と漂白助剤 力 なる薬品を挙げることができ、これらの中から適宜選択されて漂白薬品として用 レ、られる。漂白シーケンスとしては、特に限定はないが、例えば、 C/D-E/O-H Dのように原子状塩素と塩素系漂白薬品を含むシーケンス、 D— E— D、 Z-E/ O— Dのような原子状塩素を含まなレ、 ECF漂白シーケンス、 Z— E— P、 A— Z— E/ O— Pのように塩素系薬品を全く使用しない TCF漂白シーケンスを用いることができ る。 [0060] After the acid treatment, the pulp is subsequently bleached in a multi-stage bleaching step. The chemicals used are atomic chlorine (C), caustic soda (E), hypochlorite (H), chlorine dioxide (D), oxygen (〇), hydrogen peroxide (P), ozone (Z). And well-known bleaching agents such as sulfuric acid (A) and organic peracids, and bleaching aids. These can be suitably selected from these and used as bleaching chemicals. The bleaching sequence is not particularly limited. For example, a sequence containing atomic chlorine and a chlorine-based bleaching chemical such as C / DE / OH D, or a atomic bleaching sequence such as D-E-D and ZE / O-D Chlorine free, ECF bleaching sequences, TCF bleaching sequences that do not use any chlorine-based chemicals, such as Z-E-P, A-Z-E / O-P, can be used.
[0061] 本発明の高白色度化学パルプを製造する方法としては、上述した方法で得られた 漂白化学パルプをさらに紫外光及び/又は可視光による照射処理することが好まし レ、。また、光処理前の漂白化学パルプは、 ISO白色度 80%以上、好ましくは 86%以 上となるように漂白されていることが好ましい。例えば、光処理前後に P段を導入すれ ば非常に白色度の高いパルプを容易に得ることができる。 [0061] As a method for producing the high-brightness chemical pulp of the present invention, it is preferable that the bleached chemical pulp obtained by the above-described method is further subjected to irradiation treatment with ultraviolet light and / or visible light. The bleached chemical pulp before the light treatment is preferably bleached to have an ISO whiteness of 80% or more, preferably 86% or more. For example, pulp with very high whiteness can be easily obtained by introducing a P stage before and after light treatment.
[0062] 紫外光及び/又は可視光による照射処理はアルカリ性条件下で行うことが好まし レ、。アルカリ性条件としては、 pH10〜13の範囲が好ましレ、。なお、この pH調整のた めに使用するアルカリとしては、通常のアルカリ性薬剤が使用可能である力 アルカリ
として水酸化ナトリウムが好適である。また、 pH調整のために使用する酸としては、通 常の酸性薬剤が使用可能であるが、硫酸が好適である。 [0062] Irradiation treatment with ultraviolet light and / or visible light is preferably performed under alkaline conditions. As alkaline conditions, a pH range of 10 to 13 is preferred. The alkali used for the pH adjustment is a basic alkali that can be used for alkaline chemicals. Is preferably sodium hydroxide. As the acid used for adjusting the pH, ordinary acidic agents can be used, but sulfuric acid is preferred.
[0063] 紫外光及び/又は可視光による照射処理時におけるパルプ濃度は 0.1〜12重量 %が好ましい。 0.1重量％未満では漂白反応効率は高くなるものの、エネルギー効率 が低下するため好ましくない。 12重量％を超える場合には、漂白装置内でのパルプ スラリーの流動性が悪くなり、漂白反応効率が低下するため好ましくない。 [0063] The pulp concentration during irradiation treatment with ultraviolet light and / or visible light is preferably 0.1 to 12% by weight. If the content is less than 0.1% by weight, the efficiency of the bleaching reaction is increased, but the energy efficiency is reduced, which is not preferable. If the content is more than 12% by weight, the fluidity of the pulp slurry in the bleaching apparatus becomes poor, and the efficiency of the bleaching reaction is undesirably reduced.
[0064] 紫外光及び/又は可視光による照射処理時の温度にも特に制限はないが、 20〜9 5°Cが好ましい。 20°C未満では漂白反応効率が低ぐ 95°Cを超える場合には、パルプ 品質の悪化の可能性が生じることや、或いは反応装置内圧力が大気圧を超える可能 性も生じるため、耐圧性を考慮した装置設計が必要となる点で、いずれも好ましくな レ、。 [0064] The temperature at the time of the irradiation treatment with ultraviolet light and / or visible light is not particularly limited, but is preferably 20 to 95 ° C. When the temperature is lower than 20 ° C, the bleaching reaction efficiency is low.When the temperature exceeds 95 ° C, the pulp quality may deteriorate or the pressure inside the reactor may exceed the atmospheric pressure. Both are not preferable in that a device design that takes into account is necessary.
[0065] 紫外光及び/又は可視光の照射時間は、原料パルプに含まれる潜在的着色物質 の構造やその濃度を考慮することにより適宜定められる。 [0065] The irradiation time of ultraviolet light and / or visible light is appropriately determined by considering the structure and concentration of the latent coloring substance contained in the raw pulp.
[0066] 本発明において使用する紫外光及び/又は可視光としては、特別な制約はないが 、波長が 100〜400nm、好ましくは 200〜360nm程度の紫外光及び/又は可視光を 用いることが望ましい。波長が lOOnm未満の紫外光ではセルロースの光分解が促進 されるためパルプ強度及び白色度が著しく低下し、また、波長が 400nmを超える紫 外光では、着色物質の光励起が不充分であるため光漂白性が大幅に低下するので 、いずれも好ましくない。 [0066] The ultraviolet light and / or visible light used in the present invention is not particularly limited, but it is desirable to use ultraviolet light and / or visible light having a wavelength of 100 to 400 nm, preferably about 200 to 360 nm. . In the case of ultraviolet light having a wavelength of less than 100 nm, the photolysis of cellulose is accelerated, so that the pulp strength and whiteness are significantly reduced.In the case of ultraviolet light having a wavelength of more than 400 nm, the photoexcitation of the coloring substances is insufficient due to insufficient light excitation. Both are not preferred because the bleaching properties are significantly reduced.
[0067] 照射する光源としては低圧水銀灯、高圧水銀灯、キセノン灯等の通常の光源や、 各種エキシマランプや各種レーザー等も用いることができる力 大量のパルプを処理 する場合、高出力かつオゾンを発生する低圧水銀ランプを用いることが望ましい。ォ ゾン発生用紫外線ランプは主に波長 254nmの紫外光を放射しており、その他に波長 185nmの紫外光と可視光が含まれる。波長 185nmの紫外光の照射強度は温度に影 響されなレ、が、波長 254nmの紫外光の強度には温度依存性があり、 20〜40°Cで最 大となる。従って、ランプ表面温度が高くなる高出力オゾン発生用ランプではランプ 冷却に空気を使用し、冷却と同時に空気中の酸素から波長 185nmの紫外光によりォ ゾンガスを発生させてレ、る。排水処理ではこのオゾンガスが波長 254nmの紫外光で
分解され、その結果、強力な活性酸素種が生成し、着色成分の分解が顕著に促進 する。排水処理ではオゾン濃度が高いほど処理効率が向上する力 パルプ漂白では 波長 254nmの紫外光が最も漂白に有効な紫外線であるため、オゾンを過剰に供給 するとオゾンにより波長 254nmの紫外光が遮蔽され、漂白効率が低下するのみなら ず、高濃度オゾン力 発生した多量の活性酸素種でセルロース繊維の損傷が進み、 顕著な紙力低下を招く。従って、供給するオゾンには最適量があり、その量はパルプ 中の着色物質の構造やその量によって適宜調整される。 As a light source for irradiation, a normal light source such as a low-pressure mercury lamp, a high-pressure mercury lamp, a xenon lamp, and various excimer lamps and various lasers can be used. When a large amount of pulp is processed, high output and ozone are generated. It is desirable to use a low-pressure mercury lamp. The ozone generating ultraviolet lamp mainly emits ultraviolet light having a wavelength of 254 nm, and also includes ultraviolet light having a wavelength of 185 nm and visible light. The irradiation intensity of ultraviolet light with a wavelength of 185 nm is not affected by temperature, but the intensity of ultraviolet light with a wavelength of 254 nm is temperature-dependent and becomes maximum at 20 to 40 ° C. Therefore, high-power ozone generation lamps with a high lamp surface temperature use air to cool the lamp, and at the same time as cooling, generate ozone gas from oxygen in the air using ultraviolet light with a wavelength of 185 nm. In wastewater treatment, this ozone gas is converted to ultraviolet light with a wavelength of 254 nm. As a result, strong reactive oxygen species are generated, and the decomposition of the coloring component is remarkably accelerated. In wastewater treatment, the higher the ozone concentration, the higher the treatment efficiency.In pulp bleaching, ultraviolet light with a wavelength of 254 nm is the most effective ultraviolet light for bleaching. Not only does the bleaching efficiency decrease, but also a large amount of reactive oxygen species generated by high-concentration ozone force damages cellulose fibers, causing a significant decrease in paper strength. Therefore, there is an optimum amount of ozone to be supplied, and the amount is appropriately adjusted depending on the structure and the amount of the coloring substance in the pulp.
[0068] 本発明では光漂白促進剤として、従来公知の還元剤、酸化剤および水素供与性 有機化合物が全て使用できる。このような還元剤としては、例えば、ハイドロサルファ イト、水素化ホウ素化合物等を、酸化剤としては、過酸化水素、過炭酸ナトリウム、過 酢酸等を、水素供与性有機化合物としては、エタノールに代表される一級アルコー ル等を挙げることができる。また、本発明における添加剤は溶媒を使用せず、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もしくは溶解させて使用するこ とが望ましい。また、異種添加剤を混合して使用することもできる。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、水が好ましく使用される。添加剤の使用 量は、溶媒に対する添加剤の飽和濃度以下であれば特に制限はないが、好ましくは 溶媒に対して、 0.01〜40重量％、より好ましくは 0.1〜20重量％とするのが適当である [0068] In the present invention, all conventionally known reducing agents, oxidizing agents, and hydrogen-donating organic compounds can be used as the photobleaching accelerator. Such reducing agents include, for example, hydrosulfite and borohydride compounds; oxidizing agents include hydrogen peroxide, sodium percarbonate, and peracetic acid; and hydrogen-donating organic compounds include ethanol. Primary alcohol and the like. Further, the additive in the present invention may be used alone without using a solvent, but is preferably used by dispersing or dissolving it in a solvent that transmits ultraviolet and visible light. In addition, different additives can be mixed and used. 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 water is preferably used. The amount of the additive used is not particularly limited as long as it is lower than the saturation concentration of the additive with respect to the solvent, but is preferably 0.01 to 40% by weight, more preferably 0.1 to 20% by weight, based on the solvent. Is
[0069] 本発明で得られた高白色度化学パルプが退色が極めて少ない理由は明らかでは ないが、 254nmの非常に強い紫外光でパルプ中に残存する退色に関与する着色原 因物質が予め分解、除去されることで、退色試験に使用されるランプから放射される 比較的弱い紫外光では退色しなレ、ものと推察される。 [0069] It is not clear why the high-brightness chemical pulp obtained by the present invention has very little fading, but the coloring factor remaining in the pulp and involved in fading is decomposed in advance by extremely strong ultraviolet light of 254 nm. It is presumed that the relatively weak ultraviolet light emitted from the lamp used in the fading test does not fade due to removal.
[0070] 本発明の高白色度化学パルプを含有する紙の用途としては、書籍用紙の他、オフ セット印刷用紙、凸版印刷用紙、グラビア印刷用紙、新聞印刷用紙、電子写真用紙、 あるいは塗工紙、インクジェット記録用紙、感熱記録紙、感圧記録紙等の原紙として 使用すること力 Sできる。 The paper containing the high-brightness chemical pulp of the present invention may be used for book paper, offset printing paper, letterpress printing paper, gravure printing paper, newsprint paper, electrophotographic paper, or coated paper in addition to book paper. It can be used as base paper for inkjet recording paper, thermal recording paper, pressure-sensitive recording paper, etc.
[0071] 本発明の高白色度化学パルプを含有する紙は、本発明の高白色度化学パルプ以
外に原料パノレプとして化学パルプ、機械パルプ、脱墨パルプを単独または任意の割 合で混合して使用してもよい。抄紙時の pHは酸性、中性、アルカリ性のいずれでもよ レ、。 [0071] Paper containing the high brightness chemical pulp of the present invention is less than the high brightness chemical pulp of the present invention. In addition, chemical pulp, mechanical pulp, and deinked pulp may be used alone or as a mixture at an arbitrary ratio as a raw material panolep. The pH during papermaking may be acidic, neutral or alkaline.
[0072] 本発明の高白色度パルプを含有する紙には、紙力増強剤を含有させることができ る。紙力増強剤としては、デンプン、加工デンプン、ポリアクリノレアミド、ポリビュルアル コール、ポリアミド 'ポリアミン系樹脂、尿素'ホルマリン系樹脂、メラミン 'ホルマリン系 樹脂、ポリエチレンィミンなどが例示される。紙力増強剤の含有量としては、パルプ絶 乾重量当り 0.1重量 %以上、 2重量％以下が好ましレ、。 [0072] The paper containing the high brightness pulp of the present invention may contain a paper strength enhancer. Examples of the paper strength agent include starch, modified starch, polyacrylanolamide, polybutyl alcohol, polyamide 'polyamine resin, urea' formalin resin, melamine 'formalin resin, polyethyleneimine, and the like. The content of the paper strength enhancer is preferably 0.1% by weight or more and 2% by weight or less based on the absolute dry weight of the pulp.
[0073] また、本発明の高白色度パルプを含有する紙は填料を含有してもよい。填料として は、ホワイトカーボン、タルク、カオリン、クレー、重質炭酸カルシウム、軽質炭酸カル シゥム、酸化チタン、合成樹脂填料等の公知の填料を使用することができる。 [0073] Further, the paper containing the high-whiteness pulp of the present invention may contain a filler. As the filler, known fillers such as white carbon, talc, kaolin, clay, heavy calcium carbonate, light calcium carbonate, titanium oxide and synthetic resin filler can be used.
[0074] さらに、本発明の高白色度パルプを含有する紙は、必要に応じて硫酸バンド、サイ ズ剤、歩留まり向上剤、濾水性向上剤、着色剤、染料、消泡剤、嵩高剤、蛍光増白 剤等を含有してもよい。 [0074] Further, the paper containing the high-whiteness pulp of the present invention may contain, if necessary, a sulfate band, a size agent, a retention agent, a drainage agent, a coloring agent, a dye, a defoaming agent, a bulking agent, It may contain a fluorescent whitening agent and the like.
[0075] 本発明の高白色度パルプを含有する紙は、全く塗工処理をしていないか、あるい は顔料を含まない表面処理剤を塗工してもよい。非塗工用紙の場合、表面強度ゃサ ィズ性向上の目的で、水溶性高分子を主成分とする表面処理剤を塗工することが望 ましい。水溶性高分子としては、デンプン、加工デンプン、ポリアクリルアミド、ポリビニ ルアルコール等の表面処理剤として通常使用されるものを単独、あるいはこれらの混 合物を使用することができる。また、表面処理剤の中には、水溶性高分子の他に耐 水性、表面強度向上を目的とした紙力増強剤やサイズ性付与を目的とした外添サイ ズ剤を添カ卩することができる。表面処理剤の塗布量としては、表面処理剤は、 2ロー ノレサイズプレスコ一ター、ゲートローノレコーター、ブレードメタリングコーター、ロッドメ タリングコーター等の塗工機によって塗布することができる。表面処理剤の塗布量と しては、片面当り O.lgZm2以上 3gZm2以下が好ましい。 [0075] The paper containing the high-whiteness pulp of the present invention may not be subjected to any coating treatment, or may be coated with a surface treatment agent containing no pigment. In the case of non-coated paper, it is desirable to apply a surface treatment agent containing a water-soluble polymer as a main component for the purpose of improving the surface strength and size. As the water-soluble polymer, those usually used as a surface treating agent such as starch, modified starch, polyacrylamide, and polyvinyl alcohol can be used alone or in a mixture thereof. Also, in addition to the water-soluble polymer, a paper strength enhancer for improving water resistance and surface strength and an externally added size agent for imparting sizing properties should be added to the surface treatment agent. Can be. Regarding the amount of the surface treatment agent to be applied, the surface treatment agent can be applied by a coating machine such as a 2-roller size press coater, a gate roll recorder, a blade metering coater, and a rod metering coater. Is the coating amount of the surface treatment agent, per side O.LgZm 2 more 3GZm 2 or less.
実施例 Example
[0076] 次に実施例に基づき、本発明をさらに詳細に説明するが、本発明はこれら Next, the present invention will be described in more detail with reference to Examples.
に限定されるものではない。
〈パルプ物性の測定〉 However, the present invention is not limited to this. <Measurement of pulp properties>
カッパ一価の測定 カッパ一価の測定: JIS P 8211に準じて行った。 Measurement of monovalent kappa Measurement of monovalent kappa: It was performed according to JIS P 8211.
[0077] パルプの白色度測定：パルプを離解後、 Tappi試験法 T205os— 71 JIS P 822 2)に従って坪量 60g/m2のシートを作製し、 JIS P 8148に準じてパルプの白色度 を測定した。 [0077] Whiteness Measurement of pulp: after the pulp maceration, to prepare a sheet having a basis weight of 60 g / m 2 in accordance with Tappi test method T205os- 71 JIS P 822 2), measuring the brightness of the pulp according to JIS P 8148 did.
〈実験装置〉 <Experimental device>
本願実施例で用いた実験装置を図 3に示した。 FIG. 3 shows the experimental apparatus used in the example of the present application.
[0078] 光照射反応槽（1)として、 3Lガラス製シリンダー（100mm φ X 620mmH)を用い た。この光照射反応槽（1)には、図に示す攪はん機 (4)、散気管（5)の他、温度調節 装置並びに PH測定器を備えている。また、光照射光源（16W低圧水銀ランプ、 日本 フォトサイエンス社製 AY—1)は、石英ガラス管（45mm φ X 470mmH、厚さ 2mm) 内に設置し、光照射光源周辺には、空気を注入できる構造となっている。 [0078] As the light irradiation reaction tank (1), a 3L glass cylinder (100 mm X 620 mmH) was used. This light irradiation reaction vessel (1) is Stirring machine shown in FIG. (4), other diffusing pipe (5), and a temperature control unit and P H instrument. The light irradiation light source (16W low-pressure mercury lamp, AY-1 manufactured by Japan Photo Science Co., Ltd.) is installed in a quartz glass tube (45 mm φ X 470 mmH, 2 mm thick), and air is injected around the light irradiation light source. It has a structure that can be used.
[0079] [実施例 1] [Example 1]
日本製紙株式会社製の広葉樹酸素脱リグニン後のクラフトパノレプ (カッパ一価 11. 6、 ISO白色度 45. 6%)を用いた。 Kraft panolep (Kappa monovalent 11.6, ISO whiteness 45.6%) after hardwood oxygen delignification manufactured by Nippon Paper Industries Co., Ltd. was used.
[0080] 以下の条件で酸処理を行い、カッパ一価 5. 5、白色度 47. 5%のパルプを得た。 [0080] Acid treatment was performed under the following conditions to obtain pulp having a kappa monovalent value of 5.5 and a whiteness of 47.5%.
[0081] 酸処理条件：パルプ濃度 10重量％、 pH3. 0 (硫酸使用）温度 95°C、処理時間 18 0分。処理終了後、パルプを水洗した。 [0081] Acid treatment conditions: pulp concentration 10% by weight, pH 3.0 (using sulfuric acid), temperature 95 ° C, treatment time 180 minutes. After the treatment, the pulp was washed with water.
[0082] このようにして得られた酸処理パルプの 5g (絶乾)採り、パルプ濃度を 0. 25重量％ とした後、 Na〇H及び H SOを用いて酸性〜アルカリ性領域にわたる pHのパルプス ラリーを調整した。これらのスラリーを図 3の実験装置に注入し、撹拌しながら、温度 2 5°C、処理時間 120分、 254nmに主波長を持つ低圧紫外線ランプを使用の条件で 光照射反応を行った。反応を終了したパルプは、洗浄した後、シートを作成し白色度 を測定した。結果を図 4及び表 1に示した。 [0082] 5 g (absolutely dry) of the acid-treated pulp obtained in this manner was taken to a pulp concentration of 0.25% by weight, and then, using Na〇H and H SO, the pulp having a pH in the acidic to alkaline range was used. Adjusted the rally. These slurries were injected into the experimental apparatus shown in Fig. 3, and a light irradiation reaction was performed with stirring at a temperature of 25 ° C, a processing time of 120 minutes, and a low-pressure ultraviolet lamp having a main wavelength of 254 nm. After the reaction, the pulp was washed, then a sheet was prepared, and the whiteness was measured. The results are shown in FIG.
[0083] [実施例 2] [Example 2]
実施例 1と同じ広葉樹酸素脱リグニン後のクラフトパルプを用いて、以下の条件で オゾン処理を行い、カッパ一価 3. 0、白色度 56. 6%のパルプを得た。 Using the same kraft pulp after hardwood oxygen delignification as in Example 1, ozone treatment was performed under the following conditions to obtain pulp having a kappa monovalent value of 3.0 and a whiteness of 56.6%.
[0084] オゾン処理条件：パルプ濃度 10。/。、オゾン添加量 7kgZADTP、温度 50°C、処理
時間 30秒、 pH2. 5 (硫酸使用）。 [0084] Ozone treatment conditions: pulp concentration of 10. /. , Ozone added 7kg ZADTP, temperature 50 ° C, treatment Time 30 seconds, pH 2.5 (using sulfuric acid).
[0085] このようにして得られたオゾン処理パルプの 5g (絶乾)採り、実施例 1と同様な条件 で、酸性〜アルカリ性領域にわたる pHのパルプスラリー調整、及び光照射反応を行 なった後、得られたパルプの白色度を測定した。結果を図 4及び表 1に示した。 [0085] 5 g (absolutely dried) of the ozone-treated pulp thus obtained was taken, and after the pulp slurry was adjusted to pH over an acidic to alkaline range and the light irradiation reaction was performed under the same conditions as in Example 1. The whiteness of the obtained pulp was measured. The results are shown in FIG.
[0086] [比較例 1] [0086] [Comparative Example 1]
実施例 1と同じ広葉樹酸素脱リグニン後のクラフトパルプの 5g (絶乾)採り、実施例 1 と同様な条件で、酸性〜アルカリ性領域にわたる pHのパルプスラリー調整、及び光 照射反応を行なった後、得られたパルプの白色度を測定した。結果を図 4及び表 1に 示した。 After taking 5 g (absolutely dry) of the kraft pulp after the hardwood oxygen delignification as in Example 1, adjusting the pH of the pulp slurry over the acidic to alkaline range under the same conditions as in Example 1, and performing a light irradiation reaction, The whiteness of the obtained pulp was measured. The results are shown in FIG. 4 and Table 1.
[0087] [表 1] [Table 1]
[0088] [実施例 3] [Example 3]
実施例 1と同じ酸処理パルプの 5g (絶乾)採り、パルプ濃度を 0. 25重量％とした後 、（Na〇H及び H SOを用いて） pHl l . 5のパルプスラリーを調整した。このスラリー を図 3の実験装置に注入し、撹拌しながら、温度 25°C、 254nmに主波長を持つ低圧 紫外線ランプを使用の条件で、処理時間を変えた光照射反応を行った。反応を終了 したパルプは、洗浄した後、シートを作成し白色度を測定した。結果を図 5及び表 2に 示した。 5 g (absolutely dried) of the same acid-treated pulp as in Example 1 was taken, the pulp concentration was adjusted to 0.25% by weight, and then a pulp slurry having a pH of 1.5 (using Na〇H and H SO) was prepared. This slurry was injected into the experimental apparatus shown in Fig. 3, and a light irradiation reaction was performed while changing the treatment time under stirring using a low-pressure ultraviolet lamp having a main wavelength of 254 nm at a temperature of 25 ° C with stirring. After the reaction, the pulp was washed, then a sheet was prepared, and the whiteness was measured. The results are shown in FIG.
[0089] [実施例 4] [Example 4]
実施例 2と同じオゾン処理パルプの 5g (絶乾)採り、実施例 3と同様な条件で、処理 時間を変えた光照射反応を行ない白色度を測定した。結果を図 5及び表 2に示す。
[0090] [比較例 2] 5 g (absolutely dry) of the same ozone-treated pulp as in Example 2 was taken, and under the same conditions as in Example 3, a light irradiation reaction was carried out for different treatment times to measure whiteness. The results are shown in FIG. [Comparative Example 2]
比較例 1と同じ広葉樹酸素脱リグニン後のクラフトパルプの 5g (絶乾)採り、実施例 3 と同様な条件で、処理時間を変えた光照射反応を行ない白色度を測定した。結果を 図 5及び表 2に示した。 5 g (absolutely dried) of the kraft pulp after the hardwood oxygen delignification as in Comparative Example 1 was subjected to a light irradiation reaction under the same conditions as in Example 3 except that the treatment time was changed, and the whiteness was measured. The results are shown in Figure 5 and Table 2.
[0091] [表 2] [0091] [Table 2]
[0092] [実施例 5] [Example 5]
日本製紙株式会社製の針葉樹酸素脱リグニン後のクラフトパノレプ (カッパ一価 9. 1 Kraft panolep (Nippon Paper Industries Co., Ltd.) after oxygen delignification
、 ISO白色度 33. 3%)を用いた。 , ISO whiteness 33.3%).
[0093] 以下の条件で酸処理を行い、カッパ一価 9. 1、白色度 34. 3%のパルプを得た。 [0093] An acid treatment was performed under the following conditions to obtain pulp having a kappa monovalent of 9.1 and a whiteness of 34.3%.
[0094] 酸処理条件：パルプ濃度 10重量％、 pH3 (硫酸添加）温度 95°C、処理時間 180分[0094] Acid treatment conditions: pulp concentration 10% by weight, pH3 (sulfuric acid added) temperature 95 ° C, treatment time 180 minutes
。処理終了後、パルプを水洗した。 . After the treatment, the pulp was washed with water.
[0095] このようにして得られた酸処理パルプの 5g (絶乾)採り、パルプ濃度を 0. 25重量％ とした後、 Na〇H及び H SOを用いて酸性〜アルカリ性領域にわたる pHのパルプス ラリーを調整した。これらのスラリーを図 3の実験装置に注入し、撹拌しながら、温度 2 5°C、処理時間 120分、 254nmに主波長を持つ低圧紫外線ランプを使用の条件で 光照射反応を行った。反応を終了したパルプは、洗浄した後、シートを作成し白色度 を測定した。結果を図 5及び表 3に示した。 [0095] 5 g (absolutely dried) of the acid-treated pulp obtained in this manner was taken to a pulp concentration of 0.25% by weight, and then, using Na pHH and H SO, the pulp having a pH in the acidic to alkaline range was used. Adjusted the rally. These slurries were injected into the experimental apparatus shown in Fig. 3, and a light irradiation reaction was performed with stirring at a temperature of 25 ° C, a processing time of 120 minutes, and a low-pressure ultraviolet lamp having a main wavelength of 254 nm. After the reaction, the pulp was washed, then a sheet was prepared, and the whiteness was measured. The results are shown in FIG.
[0096] [比較例 3] [0096] [Comparative Example 3]
実施例 5と同じ針葉樹酸素脱リグニン後のクラフトパルプの 5g (絶乾)採り、実施例 5 と同様な条件で、酸性〜アルカリ性領域にわたる pHのパルプスラリー調整、及び光 照射反応を行なった後、得られたパルプの白色度を測定した。結果を図 6及び表 3に
示した。 After taking 5 g (absolutely dry) of the kraft pulp after the softwood oxygen delignification same as in Example 5, adjusting the pH of the pulp slurry over the acidic to alkaline range under the same conditions as in Example 5, and performing the light irradiation reaction, The whiteness of the obtained pulp was measured. The results are shown in Figure 6 and Table 3. Indicated.
[0097] [表 3] [0097] [Table 3]
[0098] [実施例 6] [Example 6]
日本製紙株式会社製の広葉樹酸素脱リグニン後のクラフトパノレプ (カッパ一価 9. 5 、 ISO白色度 47. 5%)を用いた。 Kraft panolep (Kappa monovalent 9.5, ISO whiteness 47.5%) after hardwood oxygen delignification manufactured by Nippon Paper Industries Co., Ltd. was used.
[0099] 以下の条件で酸処理を行い、カッパ一価 5. 5、白色度 48. 6%のパルプを得た。 [0099] Acid treatment was performed under the following conditions to obtain pulp having a kappa monovalent value of 5.5 and a whiteness of 48.6%.
[0100] 酸処理条件:パルプ濃度 10重量％、 pH3 (硫酸添加）、温度 85°C、処理時間 180 分。処理終了後、パルプを水洗した。 [0100] Acid treatment conditions: pulp concentration 10% by weight, pH 3 (adding sulfuric acid), temperature 85 ° C, treatment time 180 minutes. After the treatment, the pulp was washed with water.
[0101] このようにして得られた酸処理パルプの 5g (絶乾)採り、パルプ濃度を 0. 5重量％と した後、 Na〇Hを用いて pHl l . 5のパルプスラリーを調整した。これらのスラリーを図 3の実験装置に注入し、撹拌しながら、温度 25°C、処理時間 120分、 254nmに主波 長を持つ低圧紫外線ランプを使用の条件で光照射反応を行った。反応を終了した パルプは、洗浄した後、シートを作成し白色度を測定した。結果を表 4に示した。 [0101] 5 g (absolutely dried) of the acid-treated pulp thus obtained was taken to adjust the pulp concentration to 0.5% by weight, and then a pulp slurry having a pH of 1.5 was prepared using NaH. These slurries were injected into the experimental apparatus shown in Fig. 3, and a light irradiation reaction was performed with stirring at a temperature of 25 ° C, a processing time of 120 minutes, and a low-pressure ultraviolet lamp having a main wavelength of 254 nm. After the reaction, the pulp was washed, then a sheet was prepared, and the whiteness was measured. Table 4 shows the results.
[0102] [比較例 4] [0102] [Comparative Example 4]
実施例 6と同じ酸処理パルプの 15g (絶乾）採り、パルプ濃度を 0. 5重量％とした後 、図 3の実験装置に注入し、撹拌しながら、温度 25°C、 pHl l . 5で、 120分間オゾン 処理を行った（光照射光源は不使用）。この間のパルプに対する積算オゾン添加量 は、 0. 7重量％であった。結果を表 4に示した。 15 g (absolutely dry) of the same acid-treated pulp as in Example 6 was taken, the pulp concentration was adjusted to 0.5% by weight, and then poured into the experimental apparatus shown in FIG. Then, ozone treatment was performed for 120 minutes (light irradiation light source was not used). During this time, the integrated amount of ozone added to the pulp was 0.7% by weight. Table 4 shows the results.
[0103] [実施例 7] [Example 7]
実施例 6と同じ酸処理パルプを 15g (絶乾)採り、パルプ濃度を 0. 5重量％とした後 、図 3の実験装置に注入し、撹拌しながら、温度 25°C、 pHl l . 5で、 120分間、 254 nmに主波長を持つ低圧紫外線ランプを使用してオゾン処理と光照射反応を同時に 行った。この間のパルプに対する積算オゾン添加量は、 0. 7重量％であった。結果
を表 4に示した。 15 g (absolutely dry) of the same acid-treated pulp as in Example 6 was taken to a pulp concentration of 0.5% by weight, and then poured into the experimental apparatus shown in FIG. 3 and stirred at a temperature of 25 ° C. and a pH of 1.5. The ozone treatment and the light irradiation reaction were simultaneously performed using a low-pressure ultraviolet lamp having a main wavelength of 254 nm for 120 minutes. During this time, the integrated amount of ozone added to the pulp was 0.7% by weight. result Are shown in Table 4.
[0104] [実施例 8] [Example 8]
実施例 1と同じ広葉樹酸素脱リグニン後のクラフトパルプ (カッパ一価 11. 6、 ISO 白色度 45. 6%)を用いて、以下の条件でオゾン処理を行い、カッパ一価 3. 0、白色 度 56. 6。/。のパルプを得た。 Using the same kraft pulp (Kappa monovalent 11.6, ISO whiteness 45.6%) after hardwood oxygen delignification as in Example 1, ozone treatment was performed under the following conditions, and Kappa monovalent 3.0, white Degree 56. 6. /. Pulp was obtained.
[0105] オゾン処理条件：パルプ濃度 10。/。、オゾン添カ卩量 7kgZADTP、温度 55°C、処理 時間 30秒、 pH2. 5。 [0105] Ozone treatment conditions: pulp concentration 10. /. , Ozone-added syrup quantity 7kg ZADTP, temperature 55 ° C, treatment time 30 seconds, pH 2.5.
[0106] このようにして得られたオゾン処理パルプの 15g (絶乾)採り、パルプ濃度を 0. 5重 量％とした後、図 3の実験装置に注入し、撹拌しながら、温度 25°C、 pHl l . 5で、 12 0分間、 254nmに主波長を持つ低圧紫外線ランプを使用して光照射反応を行った。 結果を表 4に示した。 [0106] 15 g (absolutely dry) of the ozone-treated pulp obtained in this manner was taken to a pulp concentration of 0.5% by weight, and then poured into the experimental apparatus shown in Fig. 3, and stirred at a temperature of 25 ° C. C, a light irradiation reaction was carried out at pH 1.1 for 120 minutes using a low-pressure ultraviolet lamp having a dominant wavelength at 254 nm. Table 4 shows the results.
[0107] [表 4] [0107] [Table 4]
<パルプ物性の測定 > <Measurement of pulp properties>
•カッパ一価の測定: JIS P 8211に準じて行った。 • Measurement of monovalent kappa: It was carried out according to JIS P 8211.
'パルプの白色度測定：パルプを離解後、 JIS P 8222に従って坪量 60gZm2のシ ートを作製し、 JIS P 8148に準じてパルプの白色度を測定した。 'Measurement of whiteness of pulp: After disintegrating the pulp, a sheet having a basis weight of 60 gZm 2 was prepared according to JIS P8222, and the pulp whiteness was measured according to JISP8148.
ぐ実験装置 > Experimental equipment>
実施例で用いた実験装置を図 3に示した。光照射反応槽（20)として、 4Lガラス製 シリンダー（100mm φ X 620mmH)を用いた。この光照射反応槽（20)には、図に 示す攪はん機 (27)、散気管（24)の他、温度調節装置並びに pH測定器を備えてい る。また、光照射光源（16W低圧水銀ランプ、 日本フォトサイエンス社製 AY—1)は、 石英ガラス管（25mm φ X 470mmH、厚さ 2mm)内に設置し、光照射光源周辺に は、空気を注入できる構造となっている。本実施例においてはこの光照射光源を 2本 用いた。
[実施例 9] FIG. 3 shows the experimental apparatus used in the examples. As the light irradiation reaction tank (20), a 4L glass cylinder (100 mm X 620 mmH) was used. The light irradiation reaction tank (20) is equipped with a stirrer (27) and an air diffuser (24) as shown in the figure, a temperature controller and a pH meter. The light irradiation light source (16W low-pressure mercury lamp, AY-1 manufactured by Japan Photo Science Co., Ltd.) is installed in a quartz glass tube (25 mm x 470 mmH, 2 mm thick), and air is injected around the light irradiation light source. It has a structure that can be used. In this embodiment, two light irradiation light sources were used. [Example 9]
日本製紙株式会社製の酸素脱リグニン後の広葉樹クラフトパノレプ (カッパ一価 11. 6、 ISO白色度 45. 6%)を用い、パルプ濃度 10重量％、 pH3. 0 (硫酸で調整）、温 度 95°C、処理時間 180分で酸処理を行った。酸処理終了後パルプを水洗し、得ら れたパルプは、カッパ一価 5. 5、白色度 47. 5%であった。 Hardwood Kraft Panolep (Kappa monovalent 11.6, ISO whiteness 45.6%) after oxygen delignification manufactured by Nippon Paper Industries Co., Ltd., pulp concentration 10% by weight, pH 3.0 (adjusted with sulfuric acid), temperature The acid treatment was performed at 95 ° C for 180 minutes. After the completion of the acid treatment, the pulp was washed with water, and the obtained pulp had a kappa monovalent value of 5.5 and a whiteness of 47.5%.
上記酸処理パルプを 15g (絶乾重量)採り、水を加えてパルプ濃度 0. 5重量％のパ ルプスラリーとした後、 Na〇Hを用いてパルプスラリーの pHを 11. 5に調整した。この パルプスラリーを図 3の実験装置に注入し、撹拌しながら、温度 25°C、処理時間 120 分、 254nmに主波長を持つ低圧紫外線ランプを使用の条件で光照射処理を行った 。また、同時に、光源冷却のために図 3の石英ガラス管内に注入した空気を、散気装 置に導いて排出し、オゾン添カ卩を行った。処理を終了したパルプは、洗浄した後、シ ートを作成し白色度を測定した。結果を表 5にまとめて示した。 15 g (absolute dry weight) of the acid-treated pulp was taken, and water was added to make a pulp slurry having a pulp concentration of 0.5% by weight. Then, the pH of the pulp slurry was adjusted to 11.5 using Na〇H. This pulp slurry was injected into the experimental apparatus shown in FIG. 3 and subjected to light irradiation while stirring at a temperature of 25 ° C., a processing time of 120 minutes, and a low-pressure ultraviolet lamp having a main wavelength of 254 nm. At the same time, the air injected into the quartz glass tube of Fig. 3 for cooling the light source was guided to a diffuser and discharged, and ozone-added kneading was performed. After the treatment, the pulp was washed, a sheet was prepared, and the whiteness was measured. The results are summarized in Table 5.
[実施例 10] [Example 10]
パルプスラリーの pHを硫酸を用いて 2. 9に調整した以外は、実施例 9と同様の条 件で、光照射処理及びオゾン添加を行なった後、得られたパルプの白色度を測定し た。結果を表 5にまとめて示した。 After performing light irradiation treatment and adding ozone under the same conditions as in Example 9 except that the pH of the pulp slurry was adjusted to 2.9 using sulfuric acid, the whiteness of the obtained pulp was measured. . The results are summarized in Table 5.
[実施例 11] [Example 11]
パルプスラリーの pHを調整せず、 ρΗ6· 6とした以外は、実施例 1と同様の条件で、 光照射処理及びオゾン添カ卩を行なった後、得られたパルプの白色度を測定した。結 果を表 5にまとめて示した。 After the light irradiation treatment and the ozone-added rice pulp were performed under the same conditions as in Example 1 except that the pH of the pulp slurry was not adjusted and ρΗ6.6, the whiteness of the obtained pulp was measured. Table 5 summarizes the results.
[比較例 5] [Comparative Example 5]
オゾン添加を行わなかった（空気を図 3の石英ガラス管内に注入せず、直接散気装 置に導入してパルプスラリーに添加した。）以外は、実施例 9と同様な条件で光照射 処理を行なった後、得られたパルプの白色度を測定した。結果を表 5にまとめて示し た。 Light irradiation treatment was performed under the same conditions as in Example 9, except that ozone was not added (air was not directly injected into the quartz glass tube in Fig. 3 but was directly introduced into the diffuser and added to the pulp slurry). After that, the whiteness of the obtained pulp was measured. The results are summarized in Table 5.
[比較例 6] [Comparative Example 6]
光照射処理は行わず（光源を点灯させず）、オゾン発生装置 (オゾンスプレー、環境 工学株式会社製 NS _ 3)より発生したオゾン (濃度 50ppm)を図 3の散気装置を通し
て添加した以外は、実施例 9と同様の条件で反応を行った後、得られたパルプの白 色度を測定した。結果を表 5にまとめて示した。 No light irradiation treatment was performed (the light source was not turned on), and ozone (concentration: 50 ppm) generated from an ozone generator (ozone spray, NS_3 manufactured by Environmental Engineering Co., Ltd.) was passed through the air diffuser shown in Fig. 3. After the reaction was performed under the same conditions as in Example 9 except that the pulp was added, the whiteness of the obtained pulp was measured. The results are summarized in Table 5.
[表 5] [Table 5]
<パルプの ISO白色度の測定 > <Measurement of ISO whiteness of pulp>
パルプの白色度測定：パルプを離解後、 JIP P 8222に従って坪量 60g/m2のシ ートを作製し、 JIS P 8148に準じてパルプの ISO白色度を測定した。 Pulp whiteness measurement: After the pulp was defibrated, a sheet having a basis weight of 60 g / m 2 was prepared according to JIP P8222, and the ISO whiteness of the pulp was measured according to JIS P8148.
<パルプ > <Pulp>
広葉樹の酸素脱リグニン後のクラフトパノレプ（ISO白色度 45.6%、 日本製紙株式会 社製）を用い、これにさらに酸処理 オゾン漂白を下記の条件で行ったものを、実施 例及び比較例で使用した。 Kraft panolep (ISO whiteness 45.6%, manufactured by Nippon Paper Industries Co., Ltd.) after oxygen delignification of hardwood was used, and further subjected to acid treatment ozone bleaching under the following conditions, and used in Examples and Comparative Examples. did.
'酸処理:前記広葉樹の酸素脱リグニン後のクラフトパノレプを、パルプ濃度 10重量％ 、 pH3.0 (硫酸使用）温度 95°C、処理時間 180分で酸処理を行った。処理終了後、パ ルプを水洗した。この時のパルプの ISO白色度は 47.5%であった。 'Acid treatment: Kraft panolep after oxygen delignification of the hardwood was subjected to acid treatment at a pulp concentration of 10% by weight, a pH of 3.0 (using sulfuric acid) at a temperature of 95 ° C, and a treatment time of 180 minutes. After the treatment, the pulp was washed with water. At this time, the ISO brightness of the pulp was 47.5%.
'オゾン漂白：前記酸処理後のパルプを、パルプ濃度 10%、オゾン添加量 7kg/ (風 乾パルプ It)、温度 50°C、処理時間 30秒、 pH2.5 (硫酸使用）でオゾン漂白を行った。 処理終了後、パルプを水洗した。この時のパルプの ISO白色度は 59.7%であった。 'Ozone bleaching: ozone bleaching of the pulp after acid treatment is performed at a pulp concentration of 10%, an ozone addition amount of 7 kg / (air-dried pulp It), a temperature of 50 ° C, a treatment time of 30 seconds, and a pH of 2.5 (using sulfuric acid). went. After the treatment, the pulp was washed with water. At this time, the ISO whiteness of the pulp was 59.7%.
[実施例 12] [Example 12]
前記オゾン漂白後のパルプを、さらに下記の条件で、過酸化水素漂白 1一光漂白 —過酸化水素漂白 2の漂白シーケンスで漂白処理した。
•過酸化水素漂白 1 :パルプ濃度 10重量％、 pHl l.5 (水酸化ナトリウム使用）、温度 75 °C、処理時間 90分で行った。処理終了後、パルプを水洗した。この時のパルプの IS O白色度は 75.0%であった。 The pulp after the ozone bleaching was further bleached in the bleaching sequence of hydrogen peroxide bleaching 1 light bleaching—hydrogen peroxide bleaching 2 under the following conditions. • Hydrogen peroxide bleaching 1: Pulp concentration 10% by weight, pH 1.1 (using sodium hydroxide), temperature 75 ° C, processing time 90 minutes. After the treatment, the pulp was washed with water. At this time, the ISO whiteness of the pulp was 75.0%.
'光漂白条件：過酸化水素漂白後のパルプを 5g (絶乾重量)採り、パルプ濃度を 0.25 重量％とした後、水酸化ナトリウムを用いて pHl 1.5のパルプスラリーを調整した。これ らのスラリーを 2Lガラス製シリンダーに注入し、撹拌しながら、温度 25°C、処理時間 15 分、 254nmに主波長を持つ 16W低圧紫外線ランプ（日本フォトサイエンス社製 AY_ 1)で光照射反応を行った。処理終了後、パルプを水洗した。この時のパルプの ISO 白色度は 78.5%であった。 'Light bleaching conditions: 5 g (absolute dry weight) of pulp after bleaching with hydrogen peroxide was used to adjust the pulp concentration to 0.25% by weight, and then a pulp slurry having a pH of 1.5 was prepared using sodium hydroxide. These slurries were poured into a 2L glass cylinder, and while being stirred, a light irradiation reaction was carried out with a 16W low-pressure ultraviolet lamp (AY_1 manufactured by Japan Photoscience) having a temperature of 25 ° C, a processing time of 15 minutes, and a main wavelength of 254 nm. Was done. After the treatment, the pulp was washed with water. At this time, the ISO brightness of the pulp was 78.5%.
'過酸化水素漂白 2：光漂白処理後のパルプを上記過酸化水素漂白 1と同じ条件で 処理した。最終的に ISO白色度は 85.0%であった。 'Hydrogen peroxide bleaching 2: The pulp after the photo bleaching treatment was treated under the same conditions as the hydrogen peroxide bleaching 1 above. Finally, the ISO whiteness was 85.0%.
[実施例 13] [Example 13]
光漂白におレ、て処理時間を 30分とした以外は、実施例 1と同じ条件で漂白処理し た。光漂白後の ISO白色度は 80.0%であった。得られた光漂白処理後のパルプを上 記過酸化水素漂白 2の条件で処理した。最終的に ISO白色度は 86.1%であった。 The bleaching process was performed under the same conditions as in Example 1 except that the processing time was changed to 30 minutes. The ISO whiteness after light bleaching was 80.0%. The obtained pulp after the light bleaching treatment was treated under the conditions of the hydrogen peroxide bleaching 2 described above. Finally, the ISO whiteness was 86.1%.
[実施例 14] [Example 14]
過酸化水素漂白 1におレ、て処理時間を 45分とした以外は、実施例 1と同じ条件で 処理した。過酸化水素漂白 1後の ISO白色度は 71.0%であった。光漂白後の ISO白 色度は 74.5%であった。得られたパルプを上記過酸化水素漂白 2と同じ条件で処理 した。最終的に ISO白色度は 84.1%であった。 The treatment was carried out under the same conditions as in Example 1 except that the treatment time was changed to 45 minutes in hydrogen peroxide bleaching 1. The ISO whiteness after hydrogen peroxide bleaching 1 was 71.0%. The ISO whiteness after light bleaching was 74.5%. The obtained pulp was treated under the same conditions as in the hydrogen peroxide bleaching 2 described above. Finally, the ISO whiteness was 84.1%.
[実施例 15] [Example 15]
前記オゾン漂白後パルプを、光漂白一過酸化水素漂白の漂白シーケンスで漂白 処理した。光漂白は処理時間を 60分とした以外は実施例 12と同じ条件で実施した。 光漂白後の白色度は 75.4%であった。得られたパルプを実施例 12の過酸化水素漂 白 2と同じ条件で処理した。最終的に ISO白色度は 84.3%であった。 After the ozone bleaching, the pulp was bleached in a bleaching sequence of light bleaching hydrogen peroxide bleaching. Light bleaching was performed under the same conditions as in Example 12 except that the processing time was changed to 60 minutes. The whiteness after light bleaching was 75.4%. The resulting pulp was treated under the same conditions as in hydrogen peroxide bleaching 2 of Example 12. Finally, the ISO whiteness was 84.3%.
[実施例 16] [Example 16]
光漂白の処理時間を 120分とした以外は実施例 4と同じ条件で実施した。光漂白後 の ISO白色度は 81.8%であった。得られたパルプを実施例 12の過酸化水素漂白 2と
同じ条件で処理した。最終的に ISO白色度は 85.2%であった。 The procedure was performed under the same conditions as in Example 4 except that the processing time for light bleaching was changed to 120 minutes. The ISO whiteness after light bleaching was 81.8%. The resulting pulp was treated with hydrogen peroxide bleach 2 of Example 12. Processed under the same conditions. Finally, the ISO whiteness was 85.2%.
[実施例 17] [Example 17]
過酸化水素漂白 1におレ、て処理時間を 30分とした以外は、実施例 12と同じ条件で 処理した。過酸化水素漂白 1後の ISO白色度は 68.2%であった。光漂白後の ISO白 色度は 72.3%であった。得られたパルプを上記過酸化水素漂白 2と同じ条件で処理 した。最終的に ISO白色度は 81.7%であった。 The treatment was carried out under the same conditions as in Example 12, except that the treatment time was changed to 30 minutes in hydrogen peroxide bleaching 1. The ISO whiteness after hydrogen peroxide bleaching 1 was 68.2%. The ISO whiteness after light bleaching was 72.3%. The obtained pulp was treated under the same conditions as in the hydrogen peroxide bleaching 2 described above. Finally, the ISO whiteness was 81.7%.
[比較例 7] [Comparative Example 7]
前記オゾン漂白後パルプを、過酸化水素漂白 1一過酸化水素漂白 2の漂白シーケ ンスで漂白処理した。光漂白処理をしないこと以外は、実施例 12と同じ条件で漂白 処理した。最終的に ISO白色度は 79.3%であった。 After the ozone bleaching, the pulp was bleached in a bleaching sequence of hydrogen peroxide bleaching 1 hydrogen peroxide bleaching 2. The bleaching treatment was performed under the same conditions as in Example 12 except that the light bleaching treatment was not performed. Finally, the ISO whiteness was 79.3%.
[比較例 8] [Comparative Example 8]
前記オゾン漂白後パルプを、過酸化水素漂白 1一光漂白の漂白シーケンスで漂白 処理した。光漂白は処理時間を 60分とした以外は、実施例と同じ条件で処理した。過 酸化水素漂白 1は実施例 12と同じ条件で漂白処理した。最終的に ISO白色度は 83. 3%であった。 After the ozone bleaching, the pulp was bleached in a bleaching sequence of hydrogen peroxide bleaching 1 light bleaching. Light bleaching was performed under the same conditions as in the example except that the processing time was changed to 60 minutes. Hydrogen peroxide bleaching 1 was bleached under the same conditions as in Example 12. Finally, the ISO whiteness was 83.3%.
[比較例 9] [Comparative Example 9]
前記オゾン漂白後パルプを、過酸化水素漂白 1一光漂白 過酸化水素漂白 2の漂 白シーケンスで漂白処理した。光漂白を pH4.0 (硫酸酸性）で行った以外は、実施例 1と同じ条件で漂白処理した。光漂白後の白色度は 75.9%であった。得られたパルプ を実施例 12の過酸化水素漂白 2と同じ条件で処理した。最終的に ISO白色度は 82. 6%であった。 After the ozone bleaching, the pulp was bleached in a bleaching sequence of hydrogen peroxide bleaching, 1 light bleaching, and hydrogen peroxide bleaching. The bleaching treatment was performed under the same conditions as in Example 1 except that the light bleaching was performed at pH 4.0 (sulfuric acid). The whiteness after light bleaching was 75.9%. The resulting pulp was treated under the same conditions as for hydrogen peroxide bleaching 2 of Example 12. Finally, the ISO whiteness was 82.6%.
[0112] 実施例 12〜17、比較例 7〜9の結果を表 6に示した。 [0112] Table 6 shows the results of Examples 12 to 17 and Comparative Examples 7 to 9.
[0113] [表 6]
過酸化水素漂白 1後の 光漂白後の I so 過酸化水素漂白 2後の I I S O白色度 （％) 白色度 （％) S O白色度 （％) 実施例 1 2 7 5. 0 7 8. 5 8 5. 0 実施例 1 3 7 5. 0 8 0. 0 8 6. 1 実施例 14 7 1. 0 74. 5 84. 1 実施例 1 5 ― 7 5. 4 8 4. 3 実施例 1 6 - 8 1. 8 8 5. 2 実施例 1 Ί 68. 2 7 2. 3 8 1. 7 比較例 7 7 5. 0 - 7 9. 3 比較例 8 7 5. 0 8 3. 3 - 比較例 9 7 5. 0 7 5. 9 8 2. 6 表 6に示されるように、オゾン漂白後パルプを、過酸化水素漂白 1一光漂白一過酸 化水素漂白 2に漂白シーケンスで処理することにより、高白色度のパルプが得られた 。ただし、光漂白前の ISO白色度が 70%未満であるパルプを処理した実施例 6では 最終白色度がやや低かった。光漂白処理後に過酸化水素漂白処理をしなレ、比較例 2のシーケンスでは、 ISO白色度を 80%以上にするためには、光処理時間を大幅に 増加する必要があった。また、光漂白処理後の pHが酸性である比較例 9は実施例 1 2に比較して、光漂白後の白色度、最終白色度はいずれも低かった。 [0113] [Table 6] Iso after photoperiodic bleaching after hydrogen peroxide bleaching 1 IISO whiteness (%) whiteness (%) SO whiteness (%) after hydrogen peroxide bleaching 2 Example 1 2 7 5. 0 7 8.5 8 5.0 Example 1 3 7 5. 0 8 0 .0 8 6.1 Example 1 4 7 1. 0 74.5 84.1 Example 1 5 ― 7 5. 4 8 4.3 Example 1 6- 8 1.8 8 5.2 Example 1 Ί 68.2 7 2.3 8 1.7 Comparative example 7 7 5.0-7 9.3 Comparative example 8 7 5. 0 8 3.3-Comparative example 9 As shown in Table 6, the pulp after ozone bleaching was treated in a bleaching sequence with hydrogen peroxide bleaching, 1 light bleaching, and hydrogen peroxide bleaching, as shown in Table 6. A high brightness pulp was obtained. However, the final whiteness was slightly lower in Example 6 where pulp having an ISO whiteness of less than 70% before light bleaching was treated. The hydrogen peroxide bleaching process was not performed after the light bleaching process. In the sequence of Comparative Example 2, the light processing time had to be significantly increased in order to increase the ISO whiteness to 80% or more. In Comparative Example 9 in which the pH after the light bleaching treatment was acidic, both the whiteness after the light bleaching and the final whiteness were lower than those in Example 12.
[実施例 18] [Example 18]
日本製紙株式会ネ： tA工場の塩素漂白法により得られた広葉樹漂白パルプ (ISO白 色度 85.6%)を 200g (絶乾重量)採り、パルプ濃度を 1%とした後、水酸化ナトリウムを 用いて pHll.5に調整した。このスラリーを図 7の実験装置に注入し、撹拌しながら、 温度 25°C、処理時間 120分で紫外光漂白処理を行った。処理が終了したパルプは洗 浄した後、シートを作成し白色度を測定した。退色試験には前記白色度測定後のシ ートを用いた。また、叩解処理後のパルプからシートを作成し、裂断長を測定した。こ れらの測定方法は下記に示した通りであり、結果を表 1に示した。 Nippon Paper Industries Co., Ltd .: 200 g (absolute dry weight) of bleached hardwood bleached pulp (ISO whiteness 85.6%) obtained by the chlorine bleaching method at the tA mill was used, and after the pulp concentration was 1%, sodium hydroxide was used. And adjusted to pH11. This slurry was injected into the experimental apparatus shown in FIG. 7, and subjected to ultraviolet light bleaching at a temperature of 25 ° C. for a processing time of 120 minutes with stirring. After the treatment, the pulp was washed, a sheet was prepared, and the whiteness was measured. The sheet after the whiteness measurement was used for the fading test. Further, a sheet was prepared from the pulp after the beating treatment, and the breaking length was measured. These measurement methods are as shown below, and the results are shown in Table 1.
'フリーネスの測定：濃度 10%のパルプスラリーを PFIミルで 6000 rev処理した後、 JIS'Freeness measurement: After pulp slurry with a concentration of 10% is subjected to 6000 rev processing with a PFI mill, JIS
P 8121に準じてフリーネス（CSF)を測定した。 Freeness (CSF) was measured according to P 8121.
'パルプの白色度測定:パノレプを離解した後、 JIS P 8222に従って坪量 60g/m2 の手抄きシートを作製し、 JIS P 8148に準じてパルプの ISO白色度を測定した。 '裂断長の測定:パノレプを離解した後、 JIS P 8222に従って坪量 60g/m2のシート を作製し、 JIS P 8113に準じて裂断長を測定した。
'退色試験：キセノンランプウエザーメーターを用いて行った。キセノンランプから発生 する紫外線を 30分間サンプルに照射した後、 ISO白色度 CJIS P 8148)を測定し た。退色試験は温度 30°C、光量 67W/m2で実施した。なお、表 1中の Δ白色度、白 色度低下率は下記のように定義される。 'Measurement of whiteness of pulp: After disintegrating panolep, a hand-made sheet having a basis weight of 60 g / m 2 was prepared according to JIS P8222, and the ISO whiteness of the pulp was measured according to JISP8148. 'Measurement of breaking length: After disintegrating panolep, a sheet having a basis weight of 60 g / m 2 was prepared according to JIS P8222, and the breaking length was measured according to JISP8113. 'Discoloration test: Performed using a xenon lamp weather meter. After irradiating the sample with ultraviolet rays generated from a xenon lamp for 30 minutes, the ISO whiteness CJIS P 8148) was measured. The fading test was performed at a temperature of 30 ° C. and a light amount of 67 W / m 2 . The Δ whiteness and whiteness reduction rate in Table 1 are defined as follows.
Δ白色度 =退色試験後の ISO白色度一退色試験前の ISO白色度 Δ whiteness = ISO whiteness after fading test-ISO whiteness before fading test
白色度低下率 = Δ白色度/退色試験前の ISO白色度 Whiteness reduction rate = Δ whiteness / ISO whiteness before color fading test
•紫外光漂白実験装置:実施例で用いた実験装置を図 7に示した。 72.1ηπι ( φ ) Χ 11 80mm (Η)のガラス製円筒形の紫外光照射反応槽 (有効容積 2.64L)の中央部にォ ゾン発生用低圧紫外線ランプ（95W、 18mm ( φ ) X I 100mm (H)、セン特殊光源社 製 SUV110D)を固定し、発生したオゾンガス（540mg/h)は反応漕低部から導入され 、パルプスラリーとともに反応漕内をアップフローで移動する。光漂白後のパルプスラ リーはストックタンク（容量 30L)を経由した後、ポンプで反応槽に繰り返し送液循環で きるようにした。 • UV light bleaching experimental device: The experimental device used in the examples is shown in FIG. 72.1ηπι (φ) Χ 11 A low-pressure ultraviolet lamp (95W, 18mm (φ)) XI 100mm (H) at the center of a glass cylindrical ultraviolet light irradiation reaction tank (effective volume 2.64L) of 80mm (Η) ), SUV110D manufactured by Sen Special Light Source Co., Ltd. is fixed, and the generated ozone gas (540 mg / h) is introduced from the lower part of the reaction tank, and moves upflow in the reaction tank together with the pulp slurry. After the light bleaching, the pulp slurry passed through a stock tank (capacity: 30 L) and was then pumped so that it could be repeatedly sent to the reaction tank.
[実施例 19] [Example 19]
日本製紙株式会社 B工場のオゾン ECF漂白法 [酸処理 (酸素脱リグニンパルプ濃 度 10重量％、 pH3 (硫酸添加）、温度 85°C、処理時間 180分）、オゾン処理 (パルプ濃 度 10重量％、 pH2.5 (硫酸添加）、オゾン添加量 7kg/風乾パルプ U、温度 55°C、処 理時間 30秒） ]により得られた広葉樹漂白パルプ (ISO白色度 84.9%) 200g (絶乾重 量)採り、パルプ濃度を 1%とした後、水酸化ナトリウムを用いて pHl l.5に調整した。こ のスラリーを図 7の実験装置に注入し、撹拌しながら、温度 25°C、処理時間 120分で 紫外光漂白処理を行った。処理が終了したパルプは洗浄した後、シートを作成し白 色度を測定した。退色試験には前記白色度測定後のシートを用いた。また、叩解処 理後のパルプ力 シートを作成し、裂断長を測定した。結果を表 7に示した。 Nippon Paper Industries B Mill Ozone ECF bleaching method [Acid treatment (oxygen delignified pulp concentration 10% by weight, pH3 (sulfuric acid added), temperature 85 ° C, treatment time 180 minutes), ozone treatment (pulp concentration 10% %, PH 2.5 (sulfuric acid added), ozone added 7 kg / air-dried pulp U, temperature 55 ° C, processing time 30 seconds)], 200 g bleached hardwood pulp (ISO brightness 84.9%) Volume), the pulp concentration was adjusted to 1%, and the pH was adjusted to 1.5 with sodium hydroxide. This slurry was injected into the experimental apparatus shown in Fig. 7, and subjected to ultraviolet light bleaching at a temperature of 25 ° C and a processing time of 120 minutes with stirring. After the treatment, the pulp was washed, a sheet was prepared, and the whiteness was measured. The sheet after the whiteness measurement was used for the fading test. In addition, a pulp force sheet after beating treatment was prepared, and the breaking length was measured. The results are shown in Table 7.
[実施例 20] [Example 20]
日本製紙株式会社 C工場の ECF漂白法（二酸化塩素処理一過酸化水素処理一 二酸化塩素処理）により得られた広葉樹漂白パルプ (ISO白色度 84.3%)を 200g (絶 乾重量)採り、パルプ濃度を 1%とした後、水酸化ナトリウムを用いて pHl l.5に調整し た。このスラリーを図 7の実験装置に注入し、撹拌しながら、温度 25°C、処理時間 120
分で、紫外光漂白処理を行った。処理が終了したパルプは洗浄した後、シートを作 成し白色度を測定した。退色試験には前記白色度測定後のシートを用いた。また、 叩解処理後のパルプからシートを作成し、裂断長を測定した。結果を表 7に示した。 Nippon Paper Industries Co., Ltd. Milled 200 g (absolute dry weight) of bleached hardwood bleached pulp (ISO whiteness 84.3%) obtained by the ECF bleaching process (chlorine dioxide treatment, hydrogen peroxide treatment and chlorine dioxide treatment) at C Mill, and determined the pulp concentration. After adjusting to 1%, the pH was adjusted to 1.5 with sodium hydroxide. This slurry was poured into the experimental apparatus shown in Fig. 7 and stirred at a temperature of 25 ° C for a processing time of 120 ° C. In minutes, ultraviolet light bleaching was performed. After the treatment, the pulp was washed, a sheet was prepared, and the whiteness was measured. The sheet after the whiteness measurement was used for the fading test. Further, a sheet was prepared from the pulp after the beating treatment, and the breaking length was measured. The results are shown in Table 7.
[比較例 10] [Comparative Example 10]
日本製紙株式会ネ： tA工場の塩素漂白法により得られた広葉樹漂白パルプ (ISO白 色度 86。/0)を lOOg (絶乾重量)採り、パルプ濃度を 10%とした後、水酸化ナトリウムを 用レ、て pHl 1.5に調整した。このスラリーに過酸化水素を 3. Okg/風乾パルプ It添カロ し、温度 50°C、処理時間 180分で、漂白処理を行った。処理が終了したパルプは洗 浄した後、シートを作成し白色度を測定した。退色試験には前記白色度測定後のシ ートを用いた。また、叩解処理後のパルプからシートを作成し、裂断長を測定した。結 果を表 7に示した。 Nippon Paper Stock Society ne: tA taken plants bleached hardwood pulp (ISO whiteness 86./ 0) obtained by the chlorine bleaching process of LOOG (absolute dry weight), was a pulp concentration of 10% sodium hydroxide The pH was adjusted to 1.5 by adjusting the pH. The slurry was bleached with hydrogen peroxide at a temperature of 50 ° C. for 180 minutes at a temperature of 50 ° C. After the treatment, the pulp was washed, a sheet was prepared, and the whiteness was measured. The sheet after the whiteness measurement was used for the fading test. Further, a sheet was prepared from the pulp after the beating treatment, and the breaking length was measured. Table 7 shows the results.
[比較例 11] [Comparative Example 11]
市販の二酸化塩素 ECF漂白法により得られた広葉樹漂白パルプ (ISO白色度 89.3 %)を用いてシートを作成し白色度を測定した。退色試験には前記白色度測定後の シートを用いた。また、叩解処理後のパルプからシートを作成し、裂断長を測定した。 結果を表 7に示した。 Sheets were prepared using bleached hardwood pulp (ISO whiteness 89.3%) obtained by a commercially available chlorine dioxide ECF bleaching method, and the whiteness was measured. The sheet after the whiteness measurement was used for the fading test. Further, a sheet was prepared from the pulp after the beating treatment, and the breaking length was measured. The results are shown in Table 7.
[比較例 12] [Comparative Example 12]
日本製紙株式会ネ ±A工場の塩素漂白法により得られた広葉樹漂白パルプ (ISO白 色度 85.6%)を用いてシートを作成し白色度を測定した。退色試験には前記白色度 測定後のシートを用いた。また、叩解処理後のパルプからシートを作成し、裂断長を 測定した。結果を表 7に示した。 Sheets were prepared using hardwood bleached pulp (ISO whiteness 85.6%) obtained by the chlorine bleaching method of Nippon Paper Industries Co., Ltd. ± A mill, and the whiteness was measured. The sheet after the whiteness measurement was used for the fading test. In addition, a sheet was prepared from the pulp after the beating treatment, and the breaking length was measured. The results are shown in Table 7.
[比較例 13] [Comparative Example 13]
日本製紙株式会社 B工場の塩素漂白法により得られた広葉樹漂白パルプ (ISO白 色度 84.9%)を用いてシートを作成し白色度を測定した。退色試験には前記白色度 測定後のシートを用いた。また、叩解処理後のパルプからシートを作成し、裂断長を 測定した。結果を表 7に示した。 A sheet was prepared using bleached hardwood pulp (ISO whiteness: 84.9%) obtained by the chlorine bleaching method of Nippon Paper Industries Co., Ltd. B factory, and the whiteness was measured. The sheet after the whiteness measurement was used for the fading test. In addition, a sheet was prepared from the pulp after the beating treatment, and the breaking length was measured. The results are shown in Table 7.
[表 7]
0白 1 度 (½) 白色度 白色度低下率 叩解後の CSF 裂断長 退色試験肯 退色試験後 (%) (%) (mL) (km)[Table 7] 0 white 1 degree (½) Whiteness Whiteness reduction rate CSF breaking length after beating Fading test positive After fading test (%) (%) (mL) (km)
90.5 90.0 0.5 0.55 370 5.9990.5 90.0 0.5 0.55 370 5.99
89.0 88.4 0.6 0.67 372 5.8689.0 88.4 0.6 0.67 372 5.86
88.6 88.0 0.6 0.68 376 5.9088.6 88.0 0.6 0.68 376 5.90
89.4 86.5 2.9 3.20 375 5.62 比較俐 11 89.3 86.7 2.6 2.90 365 5.18 89.4 86.5 2.9 3.20 375 5.62 Comparison 11 89.3 86.7 2.6 2.90 365 5.18
85.6 82.5 3.1 3.60 385 5.58 比較例 1? 84.9 82.0 2.9 3.40 380 5.64
85.6 82.5 3.1 3.60 385 5.58 Comparative Example 1? 84.9 82.0 2.9 3.40 380 5.64
Claims
請求の範囲 The scope of the claims
[I] パルプの漂白方法であって、酸処理後洗浄したパルプをアルカリ性条件下で、波長 [I] A method for bleaching pulp, in which pulp washed after acid treatment is treated under alkaline conditions with a wavelength
100〜400nmの紫外光及び/又は可視光を照射することを特徴とするパルプの漂 白方法。 A method for bleaching pulp, which comprises irradiating ultraviolet light and / or visible light of 100 to 400 nm.
[2] 前記アルカリ性条件力 pH10〜13の範囲であることを特徴とする請求項 1記載のパ ルプの漂白方法。 2. The method for bleaching pulp according to claim 1, wherein the alkaline condition is in a pH range of 10 to 13.
[3] 前記酸処理が、 ρΗ1〜6、温度 80°C以上の条件下で行われることを特徴とする請求 項 1又は 2いずれか記載のパルプの漂白方法。 3. The pulp bleaching method according to claim 1, wherein the acid treatment is performed under conditions of ρΗ1 to 6 and a temperature of 80 ° C. or higher.
[4] 前記酸処理が、オゾンの存在下、 pHl . 0〜8. 0、温度 25〜95°C、の条件下で行わ れることを特徴とする請求項 1又は 2いずれか記載のパルプの漂白方法。 [4] The pulp according to claim 1 or 2, wherein the acid treatment is performed in the presence of ozone under conditions of pH 1.0 to 8.0 and a temperature of 25 to 95 ° C. Bleaching method.
[5] 光照射処理が、還元剤、過酸化物、水素供与性有機化合物の群の中から選ばれた 少なくとも 1種類の化合物の存在下で行われることを特徴とする請求項 1〜4いずれ か記載のパルプの漂白方法。 [5] The method according to any one of claims 1 to 4, wherein the light irradiation treatment is performed in the presence of at least one compound selected from the group consisting of a reducing agent, a peroxide, and a hydrogen-donating organic compound. Or the method for bleaching pulp according to the above.
[6] 前記紫外光及び/又は可視光の照射光源が、波長特性の異なる複数光源からなる ことを特徴とする請求項 1〜5いずれか記載パルプの漂白方法。 6. The pulp bleaching method according to any one of claims 1 to 5, wherein the ultraviolet and / or visible light irradiation light source comprises a plurality of light sources having different wavelength characteristics.
[7] 光照射処理を複数回繰り返すことを特徴とする請求項:!〜 6いずれか記載のパルプ の漂白方法。 [7] The method for bleaching pulp according to any of [1] to [6], wherein the light irradiation treatment is repeated a plurality of times.
[8] 酸処理後洗浄したパルプに対して、オゾンの存在下で波長 100〜400nmの紫外光 及び/又は可視光による照射処理をすることを特徴とするパルプの漂白方法。 [8] A method for bleaching pulp, which comprises subjecting washed pulp after acid treatment to irradiation with ultraviolet light and / or visible light having a wavelength of 100 to 400 nm in the presence of ozone.
[9] 前記の紫外光及び Z又は可視光による照射処理力 ¾H2〜4の酸性条件下、または p H10〜： 13のアルカリ性条件下で行われることを特徴とする請求項 8記載のパルプ処 理方法。 [9] The pulp treatment according to claim 8, wherein the irradiation treatment with ultraviolet light and Z or visible light is performed under an acidic condition of H2 to 4 or an alkaline condition of pH 10 to 13. Method.
[10] 前記酸処理が pH：!〜 6、温度 80〜： 180°Cの条件下で行われることを特徴とする請求 項 8なレ、し 9記載のパルプの漂白方法。 [10] The method for bleaching pulp according to claim 8, wherein the acid treatment is performed under the conditions of pH:! -6, temperature: 80-180 ° C.
[II] 前記酸処理が、オゾンの存在下で、かつ ρΗ1〜8、温度 25〜95°Cの条件下で行わ れることを特徴とする請求項 8〜： 10のいずれかに記載のパルプの漂白方法。 [II] The pulp according to any one of claims 8 to 10, wherein the acid treatment is performed in the presence of ozone and under conditions of ρΗ1 to 8 and a temperature of 25 to 95 ° C. Bleaching method.
[12] 前記オゾンは、空気若しくは酸素又はそれらの混合物に紫外光を照射することにより 発生させることを特徴とする請求項 8〜： 11のいずれかに記載のパルプの漂白方法。
12. The pulp bleaching method according to claim 8, wherein the ozone is generated by irradiating air or oxygen or a mixture thereof with ultraviolet light.
[13] 照射処理時におけるオゾンの濃度が 0· 5〜： !OOppmであることを特徴とする請求項[13] The ozone concentration during irradiation treatment is from 0.5 to:! OOppm.
8〜： 12のいずれかに記載のパルプの漂白方法。 8 to: The pulp bleaching method described in any of 12 above.
[14] 紫外光及び/又は可視光の照射光源の周囲に空気若しくは酸素又はこれらの混合 物を供給しオゾンを発生させ、該オゾンを含有する気体をパルプに添加することを特 徴とするパルプの漂白装置。 [14] A pulp characterized in that air or oxygen or a mixture thereof is supplied around an irradiation source of ultraviolet light and / or visible light to generate ozone, and a gas containing the ozone is added to the pulp. Bleaching equipment.
[15] 紫外光及び/又は可視光を発生させる照射光源をその中に有するオゾン発生漕、 及びパルプスラリー漕からなるパルプの漂白装置にぉレ、て、前記オゾン発生漕は、 気体注入口及び排出口を有しており、前記排出口は、パルプスラリー漕と連通してい る、前記漂白装置。 [15] An ozone generation tank having an irradiation light source for generating ultraviolet light and / or visible light therein, and a pulp bleaching apparatus including a pulp slurry tank, wherein the ozone generation tank has a gas inlet and The bleaching apparatus having an outlet, wherein the outlet communicates with a pulp slurry tank.
[16] 酸素脱リグニン処理したパルプを酸処理後、完全無塩素漂白で使用される漂白方法 により漂白したパルプを、アルカリ性条件下で波長 100〜400nmの、紫外光及び Z又 は可視光による光漂白処理を行った後、アルカリ性過酸化水素漂白を行うことを特徴 とする化学パルプの完全無塩素 (TCF)漂白方法。 [16] Oxygen delignified pulp is acid-treated, then bleached by the bleaching method used in complete chlorine-free bleaching, under alkaline conditions, ultraviolet light of wavelength 100 to 400 nm, and light of ultraviolet or Z or visible light. A completely chlorine-free (TCF) bleaching method for chemical pulp, which comprises performing a bleaching treatment followed by alkaline hydrogen peroxide bleaching.
[17] 酸素脱リグニン処理したパルプを酸処理後、通常の TCF漂白で使用される漂白方法 により ISO白色度 70〜75%としたパルプを、アルカリ性条件下で波長 100〜400nmの 、紫外光及び/又は可視光による光漂白処理を行って ISO白色度 75〜80%にした 後、さらにアルカリ性過酸化水素漂白を行って ISO白色度 84%以上のパルプを得る ことを特徴とする化学パルプの完全無塩素漂白方法。 [17] Oxygen delignified pulp is acid-treated, and pulp with ISO whiteness of 70-75% is bleached by the bleaching method used in ordinary TCF bleaching. A chemical pulp that is characterized in that pulp with ISO whiteness of 84% or more is obtained by subjecting it to ISO whiteness of 75 to 80% by light bleaching treatment with visible light and then performing alkaline hydrogen peroxide bleaching. Chlorine-free bleaching method.
[18] 前記光漂白処理を pH10〜13の範囲で行うことを特徴とする請求項 1ないし 2記載の 化学パルプの漂白方法。 18. The method for bleaching chemical pulp according to claim 1, wherein the light bleaching treatment is performed in a pH range of 10 to 13.
[19] 前記酸処理を ρΗ1〜6、温度 80°C以上の条件下で行うことを特徴とする請求項 16〜 [19] The method according to claim 16, wherein the acid treatment is performed under the conditions of ρΗ1 to 6 and a temperature of 80 ° C or more.
18のいずれかに記載の化学パルプの漂白方法。 18. The method for bleaching chemical pulp according to any one of 18.
[20] 前記光漂白処理が、酸化剤、還元剤、過酸化物の群の中から選ばれた少なくとも 1種 類の化合物の存在下で行われることを特徴とする請求項 16〜： 19のいずれかに記載 の化学パルプの漂白方法。 [20] The method according to claims 16 to 19, wherein the photo-bleaching treatment is performed in the presence of at least one compound selected from the group consisting of an oxidizing agent, a reducing agent and a peroxide. The method for bleaching chemical pulp according to any one of the above.
[21] ISO白色度が 88%以上であって、下記の退色試験： [21] ISO whiteness of 88% or more and the following fading test:
QIS P 8222に従って手抄き紙を作成し、 J. TAPPI No. 21 紙及び板紙—退 色度試験方法の B法（キセノンアークランプ式耐光性試験器による方法）に準じて 30
°Cの環境下で、光量 67W/m2のキセノンランプを 30分間照射した後、 ISO白色度を 測定し、処理前の ISO白色度との低下率を求める。 ) Hand-made paper was prepared in accordance with QIS P 8222, and was prepared according to J. TAPPI No. 21 Paper and paperboard-Discoloration test method B method (method using a xenon arc lamp type light resistance tester). After irradiating a xenon lamp with a light intensity of 67 W / m 2 for 30 minutes in an environment of ° C, measure the ISO whiteness and determine the rate of decrease from the ISO whiteness before processing. )
において白色度の低下率が 1.0%以下である高白色度化学パルプ。 High-brightness chemical pulp having a whiteness reduction rate of 1.0% or less.
[22] 紫外光及び/又は可視光で処理された化学パルプであって、 ISO白色度が 88%以 上である請求項 21記載の高白色度化学パルプ。 [22] The high brightness chemical pulp according to claim 21, which is a chemical pulp treated with ultraviolet light and / or visible light, and has an ISO whiteness of 88% or more.
[23] 請求項 21ないし 22記載の高白色度化学パルプを含有する紙。 [23] A paper containing the high brightness chemical pulp according to claim 21 or 22.
[24] 漂白化学パルプを紫外光及び Z又は可視光で処理することを特徴とする高白色度 化学パルプの製造方法。 [24] A method for producing high-brightness chemical pulp, comprising treating bleached chemical pulp with ultraviolet light and Z or visible light.
[25] ISO白色度が 80%以上である漂白化学パルプを紫外光及び Z又は可視光で処理し 、 ISO白色度が 88%以上となるように漂白することを特徴とする高白色度化学パルプ の製造方法。
[25] A high-brightness chemical pulp characterized in that bleached chemical pulp having an ISO whiteness of 80% or more is treated with ultraviolet light and Z or visible light and bleached so that the ISO whiteness becomes 88% or more. Manufacturing method.
Priority Applications (4)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| CN2005800255211A CN1993518B (en) | 2004-06-08 | 2005-06-08 | Pulp bleaching processes |
| US11/628,961 US20070246176A1 (en) | 2004-06-08 | 2005-06-08 | Pulp Bleaching Processes |
| EP05748560A EP1790771A4 (en) | 2004-06-08 | 2005-06-08 | Pulp bleaching processes |
| CA2569848A CA2569848C (en) | 2004-06-08 | 2005-06-08 | Pulp bleaching processes |
Applications Claiming Priority (8)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| JP2004169367A JP4603298B2 (en) | 2004-06-08 | 2004-06-08 | Pulp bleaching method |
| JP2004-169367 | 2004-06-08 | ||
| JP2004-289267 | 2004-09-30 | ||
| JP2004289267A JP2006104587A (en) | 2004-09-30 | 2004-09-30 | Highly white-colored chemical pulp and method for producing the same |
| JP2005102558A JP2006283211A (en) | 2005-03-31 | 2005-03-31 | Method for bleaching chemical pulp |
| JP2005-102558 | 2005-03-31 | ||
| JP2005-102615 | 2005-03-31 | ||
| JP2005102615A JP2006283213A (en) | 2005-03-31 | 2005-03-31 | Method and apparatus for bleaching pulp |
Publications (1)
| Publication Number | Publication Date |
|---|---|
| WO2005121442A1 true WO2005121442A1 (en) | 2005-12-22 |
Family
ID=35503100
Family Applications (1)
| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| PCT/JP2005/010521 WO2005121442A1 (en) | 2004-06-08 | 2005-06-08 | Method for bleaching pulp |
Country Status (4)
| Country | Link |
|---|---|
| US (1) | US20070246176A1 (en) |
| EP (1) | EP1790771A4 (en) |
| CA (1) | CA2569848C (en) |
| WO (1) | WO2005121442A1 (en) |
Cited By (3)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| WO2008011523A2 (en) | 2006-07-21 | 2008-01-24 | Nalco Company | Improved compositions and processes for paper production |
| US8268120B2 (en) * | 2006-12-13 | 2012-09-18 | Itt Manufacturing Enterprises, Inc. | Method for bleaching chemical paper pulps by final ozone treatment at high temperature |
| JP2013198424A (en) * | 2012-03-23 | 2013-10-03 | Nippon Paper Industries Co Ltd | Treatment method of plant-based raw material |
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| AU2007316938B2 (en) * | 2006-11-09 | 2011-10-06 | Oci Nitrogen B.V. | Process for the preparation of a panel |
| US7867358B2 (en) * | 2008-04-30 | 2011-01-11 | Xyleco, Inc. | Paper products and methods and systems for manufacturing such products |
| US7867359B2 (en) | 2008-04-30 | 2011-01-11 | Xyleco, Inc. | Functionalizing cellulosic and lignocellulosic materials |
| ES2456271T3 (en) | 2008-06-20 | 2014-04-21 | International Paper Company | Composition and registration sheet with improved optical properties |
| CN104372704A (en) * | 2014-09-15 | 2015-02-25 | 岳阳林纸股份有限公司 | Chemical-mechanical pulp H2O2+OBA relay axurilary bleaching method |
| US10143993B2 (en) * | 2015-08-18 | 2018-12-04 | Lam Research Corporation | Radical generator and method for generating ammonia radicals |
| JP6992760B2 (en) * | 2016-09-30 | 2022-01-13 | 王子ホールディングス株式会社 | Pulp, slurry, sheet, laminate and pulp manufacturing method |
| CN115110329A (en) * | 2022-06-28 | 2022-09-27 | 中国制浆造纸研究院有限公司 | Method for reducing metal content and ash content in bleaching section pulp |
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| JP2013198424A (en) * | 2012-03-23 | 2013-10-03 | Nippon Paper Industries Co Ltd | Treatment method of plant-based raw material |
Also Published As
| Publication number | Publication date |
|---|---|
| EP1790771A4 (en) | 2012-10-03 |
| EP1790771A1 (en) | 2007-05-30 |
| US20070246176A1 (en) | 2007-10-25 |
| CA2569848A1 (en) | 2005-12-22 |
| CA2569848C (en) | 2011-05-10 |
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