AU647891B2

AU647891B2 - Process for bleaching pulp

Info

Publication number: AU647891B2
Application number: AU11688/92A
Authority: AU
Inventors: Yoshinori Kashino; Ryuichiro Kondo; Tomoaki Nishida; Kokki Sakai; Yoshimasa Takahara
Original assignee: Kobe Steel Ltd
Current assignee: Kobe Steel Ltd
Priority date: 1991-01-21
Filing date: 1992-01-16
Publication date: 1994-03-31
Anticipated expiration: 2012-01-16
Also published as: FI923798A; SE9202592L; AU1168892A; WO1992013131A1; CA2076679A1; SE9202592D0; FI923798A0; JPH04240287A

Description

OPI DATE 27/08/92 c .AOJP DATE 01/10/92 APPIN. ID 1.1688 I 92 PCI NUMBER PCT/jpq2/00fl27 0) D21C 9/10, C12S 3/08

A

1 (43) M M H 992 *816 H6(06. 08. 1992) (21) g~ht4 PCT/JP92/00027 (74) ftgA (22) 9 h F 199Vf1J916E3(16. 01. 92) Jf9 jnEBV(TODA, Chikao) f~f-9 ~ff Tokyo. (JP) -"0F /7 1 9 1991_,21A21B(21. 01. 91) JP (71) WRA (*M1 3(wW-t A U, CA, P I. S E, US.

(KABUSH-IKI KAISHA KOBE SEIKO SH-O) (JP/JPD )ffaH4~f 7651 T1~~84 Hyogo, (JP) MB:TEOBNISHIDA, Tomnoaki JP/JP) Ibaragi, (JP)I MTW9(KASHINO, Yos h ino r i) CJ/JP) 7812 VRM$FZF3TH12fY01S-1054- Fukuoka, (JP) 0MAM(TAKAHARA, Y os h imra s a JP/JFP) 7i275 f9W -5TB]29-8 Chiba, (JP) wrZ#AE(SAKAI, Kokki)CJP/JP) Ti81 1-32 63t33 Fukuoka, (JP) Ry u ic h iro )CJP/JP 7813 WAA&1tXFt*1T3' 38-408-U Fukuoka, (JP) (54)Title: PROCESS FOR BLEACHIING PULP (54) Rq-0'k (57) Abstract A process for bleaching pulp by a combination of a microbial treatment and a treatment with a chlorine-free chemical.

Pulp can be bleached at a high efficiency while completely preventing the generation of dioxin and the like when no chlorinated chemical is used at all in this invention.

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SPECIFICATION

Title of the Invention METHOD OF PULP BLEACHING Field of the Invention The present invention relates to bleaching of pulp of wood resources. More precisely, it relates to a method of pulp bleaching, which comprises combination of treatment with microorganism having a high lignin-degrading activity and a low fiber-degrading activity, with the culture of such microorganism or with the processed product thereof to degrade lignin in the pulp and treatment with chlorine-free chemical.

In accordance with the present invention, since pulp may be bleached in the absence of chlorine-based chemicals and/or in the presence of a noticeably reduced amount of them, generation of environment polluting substances such as i dioxin and chlorinated phenols from chlorine-based chemicals can completely be prevented and/or can noticeably be reduced. Thus, the present invention is important in the point that it can bleach pulp without environmental i pollution.

Prior Arts and Problems Unbleached chemical and semi-chemical pulps to be obtained after digestion of a raw material wood chip still contain a strongly colored-lignin. Therefore, for use of them in preparing high quality paper or the like needing a high-brightness, bleaching is necessary for removing the remaining lignin from them so as to impart the brightening thereto.

c~ 1 r- 2 The mainstream of the current bleaching technology in this technical field is a multi-stage chlorine-based bleaching process comprising treatment with chlorine alkali (E 1 sodium hypochlorite alkali (E 2 chlorine dioxide In accordance with the 'process, however, since the bleaching waste liquor from the process contains much chlorine to cause corrosion of metals, concentration and combustion in the chemical recovering step for digestion and re-cycle and re-use in the bleaching step are difficult. Because of the reasons, the bleaching waste liquor is, after having been treated by an activated sludge process or coagulation and sedimentation process, taken out from the system. However, since the processedwaste liquor contains carcinogenic dioxin and chlorinated phenols, prevention of environmental pollution by chlorinebased chemicals is now an important theme Rappe, S.

Swanson, B. Glas, K.P. Kringstad, F. De Sousa, L. Johansson and Z. Age; Pulp and Paper Canada, 90, T273 (1989)).

From the viewpoint, a bleaching method with chlorine-free chemicals has become marked, and bleaching by treatment with oxygen and alkali (oxygen bleaching) is now being put to practical use. Oxygen bleaching is such that sodium hydroxide is added to an unbleached pulp and the pulp is treated with oxygen under the condition of an oxygen pressure of from 5 to 10 kg/cm 2 and a temperature of from 110 to 140 0

C

for delignification. Using this, substitution of a part of the chlorine treating stage in the multi-stage chlorinebased bleaching process by oxygen bleaching is possible, whereby pollution with chlorine-based chemicals, can be 3 reduced in the process Croon and D. H. Andrews; TaPPi, 54, 1983 (1971)).

Problems to be Solved by the Invention However, since it is impossible to obtain a fullbleached pulp having a brightness of about 85 by only oxygen bleaching, it is the current situation that the stages after the oxygen bleaching stage are obliged to use a large amount of chlorine-based chemicals still in the same manner as in the conventional means. As a matter of course, the bleaching waste liquors after oxygen bleaching stage contain environmental polluting substances such as dioxin. Therefore, if chlorine-free chemicals are not used in the stages after oxygen bleaching and/or if use of chlorine-based chemicals in them is not reduced drastically, it would be impossible to completely prevent and/or noticeably reduce generation of environmental polluting substances in the process of pulp bleaching.

From the points, the present inventors have already tried to use hydrogen peroxide, which is a chlorine-free chemical, in the stages after oxygen bleaching to bleach pulp so as to completely prevent generation of enironmental polluting substances. However, where a full-bleached pulp having a brigntness of about is desired to be obtained by the process of using hydrogen peroxide, the yield of the bleached pulp and the viscosity of it noticeably lower due to degradation of cellulose. Therefore, the process has not been put to practical use Nishida, K. Sakai T. Kondo; Japan TAPPI Journal, 28, 564 (1974)).

4 Means for Solving the Problems The present invention has been made in consideration of the current technical level that production of a fullbleached pulp by selective degradation and removal of lignin with repressing degradation of cellulose in an unbleached pulp is impossible by oxygen/alkali treatment and by combination of oxygen/alkali treatment and hydrogen peroxide treatment. After investigation from various physical, chemical and biological aspects, the present inventors knew that the conventional physical and chemical treatments are limited so that they have noted biological treatment, especially with microorganisms, in pulp bleaching.

However, even after various trials of treatment with microorganisms in pulp bleaching, they could not attain the intended object and they were obliged to drastically convert their ideas. Under the situation, they tried to combine other treatments along with screening of microorganisms capable of being used in them and, as a result, they have noted combination of microorganisms having excellent selective l.ignin-degrading activity and chlorine-free chemicals for delignification of an unbleached pulp. After all, they have attained the intended object due to such combination.

4Ac microrganizms for use .in-..pr-ent invention, microorganisms having a high lignin- degradai ctivity and having a low fiber-degradin activity, or that is, those capable of ively and highly degrade lignin can be used sinqly or in combination of plural kinds of them.

5 In a broad aspect, the present invention provides a method of pulp bleaching comprising the steps of treating/bleaching the pulp with microorganism NK-1148 strain combined with a chemical chlorine-free treatment.

The NK-1148 strain used with the present inventive method has the following microbial properties.

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IP

6 State of Growth in Various Media: Culture Medium State of Growth Malt Extract Agar Medium Potatc-Glucose Agar Medium Czapek's Agar Medium Sabouraud's Agar Medium Synthesized Mucor Agar Medium YpSs Agar Medium Glucose-Dried Yeast Agar Medium Note-1, Culture Medium pH: 5.0 (before autoclave sterilization) Note-2, Culture Condition: 28 0 C x 7 days

I

Note-3, State of Growth: Weak: Medium: Abundant: Physiological and Morphological Properties: pH range for growth (cultivation in potato-glucose agar medium, 28 0 C, 4 days): Grows at a pH of about 3-9, and not grow i at pH 2 and 10. 'The optimum pH range for the growth is approximately from 4 to 6.

O Temperature range for growth (cultivation in potato-glucose agar medium, pH 5, 4 days): Grows at a temperature of about 10-450C, and not grow at 50 0 C. The optimum temperature range for the growth is approximately from 28 to 37 0

C.

ii 1 7 0 Phenol oxidase reaction (cultivation at 28 0 C, 4 days): Shows weak or negative.

Morphology of colony (cultivation in potato-glucose agar medium, pH 5, 28 0 C, 4 days): White and felt-like.

NK-1148 strain was identified not only to be superior in lignin-degrading activity than fungi of the genera Coriolus and Phanerochaete, which have heretofore been especially well-known as lignin-degrading fungi, but also to have an especially excellent selectivity of the lignin degradation. The present inventors admitted that the strain is novel and named it NK-1148. The strain was deposited in Fermentation Research Institute, Agency of Industrial Science and Technology (Japan) as FERM BP-1859.

For degradation of lignin with microorganism, lignindegrading microorganism, the culture of the microorganism, or the processed product thereof is added to a medium containing pulp and treated at a temperature of 20 to 40°C for a determined period of time. Where lignin-degrading microorganism is used, water and a suspension of the microorganism are added to pulp and aerobical incubation is carried out for a determined period of time under the condition of a pulp consistency of approximately from to 30 In place of water, a liquid medium containing glucose and other nutrient sources may also be used with no problem.

The culture of lignin-degrading fungus widely means a mixture comprising the mycelia of the fungus and medium, obtained by culturing. Further, in the present invention, the 8 mycelia separated from the culture and the residue obtained by said separation, as well as the culture broth from which all solids have been removed, may be used. The processed product means any product obtained by concentrating, drying or diluting each material above-mentioned.

In the present invention, the microbial treatment and the treatment with chlorine-free chemical may be suitably combined, and the order and the frequency of these treatments are not specifically defined. If desired, the process of the present invention may further be combined with light chlorine-based chemical treatment.

The treatment with chlorine-free chemical to be effected in the present invention includes all treatments with chlorine-free chemical(s) which are known in the current paper pulp industrial field. As unlimited examples of them, there are mentioned oxygen/alkali treatment, treatment with peroxide type chemicals hydrogen peroxide, sodium peroxide, sodium percarbonate), treatment with peracid type chemicals peracetic acid, performic acid, perbenzoic acid, permanganates, persulfates), ozone treatment and/or Salkali treatment. As the conditions for such treatments, various conditions which are employed in the current paper pulp industry may well be used.

The treatment with chlorine-based chemical which may optionally be combined with the process of the present invention includes all treatments with chlorine- based chemical(s) which are known in the current paper pulp industrial field. For example, there are mentioned chlorine

LL

1 i i 9 treatment, chlorine dioxide treatment and/or hypochlorite treatment. As the conditions for such treatments, various conditions which are employed in the current paper pulp industry may well be used.

As the unbleached pulp to be bleached by the method of the present invention, usable are unbleached chemical pulps and/or semi-chemical pulps of broadleaf trees and/or coniferous trees as prepared by conventional digestion-method, such as kraft, soda or sulfite pulp.

Next, examples of the present invention are mentioned below.

EXAMPLE 1: An unbleached kraft pulp made of beech was subjected to oxygen/alkali treatment (NaOH amount added: 2 to pulp, pulp consistency: 20 oxygen pressure: 5 kg/cm 3 treating temperature: 100 0 C, treating time: 30 minutes, MgCO 3 amount added: 0.5 to pulp) and then washed with water, 250 ml of water was added to 100 g (as absolute dry weight) of the oxygen/alkali .treated pulp brightness: 47.8 Kappa number: 11.4) and was sterilized at 120 0 C for minutes. Then, a mycelial suspension of NK-1148 strain (FERM BP-1859) was added thereto and the pulp consistency in the resulting blend was made to be 20 Under the condition, incubation was carried oit at 28 0 C for 3 days and the culture was then washed with water.

Next, the NK-1148 strain treated pulp brightness: 70.0 Kappa number: 5.4) was treated with hydrogen peroxide (H202 amount added: 2 to 4 to pulp, NaOH amount added: to 4 to pulp, pulp consistency: 10 treating OL6VLL. L- SL U L a LL Declarant's Name Kensaburo TAKISAWA..... E B. RICE CO PATENT ATTORNEYS Thlis orni is illk l fir any tlype of latent Application. No legalisation required, 10 temperature: 60 0 C, treating time: 2 hours) and then washed with water. The brigntness (JIS P8123-1961) of the thus treated pulp and the bleached pulp yield were measured.

As control, the oxygen/alkali treated pulp was directly treated with hydrogen peroxide (H 2 0 2 amount added: 2 to 6 to pulp, NaOH amount added: 0.5 to 3 to pulp, pulp consistency 10 treating temperature: 60 0 C, treating time: 2 hours), without treatment with NK-1148 strain.

The results obtained are shown in Table 1 below.

Wil lii WCIII wuii viru r ju l- 11 Table 1 Bleaching Sequence and Pulp Properties Amounts of Chemicals added Bleaching Sequence in P stage to pulp) Bleaching Sequence H202 NaOII Embodiment O-F-P 2.0 of the 2.0 Invention 4.0 Control O-P 2.0 Table 1 continued Brightness Bleached Pulp Yield to after heat unbleached pulp) after air dried treated Embodiment 84.3 80.6 94.3 ofthe 84.5 81.7 94.1 invention 85.7 81.2 94.0 86.5 81.7 93.7 Control 72.4 -93.4.

73.3 -91.8 74.4 -90.3 75.5 87.4 Notes: 0 Oxygen/alkali treatment, F NK-1148 strain treatment P Hydrogen peroxide treatment -I -I wuji iiii I L .C 3 12 As is obvious from the results as mentioned above, the following matters were confirmed. Precisely, in accordance with the process of the present invention comprising combination of the microbial treatment and the chlorine-free chemical treatment, a full-bleached pulp can be obtained easily with a high yield. As opposed to this, however, by only the chlorine-free chemical treatment in the control case, it was difficult to obtain a fullbleached pulp having a brightness of about 85 even though a large amount of hydrogen peroxide was used. In addition, decrease of the bleached pulp yield due to brightening of pulp was noticeable in the control case, as opposed to the embodiment of the present invention.

EXAMPLE 2: A washed NK-1148 strain treated pulp was prepared in the same manner as in Example i. This was further treated with NaOH (NaOH amount added: 1.5 to pulp, pulp consistency: treating temperature: 70 0 C, treating time: 40 minutes).

After washed with water, it was treated with hydrogen peroxide (H 2 0 2 amount added: i, 2 or 4 to pulp, NaOH amount added: 0.3, 0.5 or 2.0 to pulp, pulp consistency: 0 treating temperature: 60 0 C, treating time: 2 hours). The samples thus treated were compared with those of Example 1 which were not treated with NaOH after the NK-1148 strain treatment, with respect to the brightness of the bleached pulp and the bleached pulp yield.

The results obtained are shown in Table 2 below.

6 13 Table 2 Comparison of Bleaching Sequences Amount of Chemicals Added to pulp) Bleaching P stage Sequence E stage NaOHNa

H

2 0 2 NaOH O-F-E-P 1.5 1.0 0.3 2.0 4.0 O-F-P 0 2.0 0 2.0 0 4.0 0 4.0 Table 2 -continued Brightness (f) Brightnes Bleached Pulp Yield to unbleached after air dried after heat treated pulp) 84.2 80.7 94.3 85.8 81.5 93.9 87.2 83.1 93.7 84.3 80.6 94.3 84.5 81.7 94.1 85.7 81.2 94.0 86.5 81.7 93.7 Notes: O Oxygen/alkali treatment, F NK-1148 strain treatment E Sodium hydroxide treatment, P Hydrogen peroxide treatment ~ricli~ 14 As is obvious from the results as mentioned above, the following matters were confirmed. Precisely, by effecting the sodium hydroxide treatment, lignin decomposed to low-molecule or modified lignin was removed from the NK-1148 strain treated pulp so that the lignin content as remained in the treated pulp decreased. Therefore, in the case as combined with the NaOH treatment, the amount of hydrogen peroxide necessary for obtaining the brightness of the same level was smaller than that in the case not combined with the NaOH treatment.

EXAMPLE 3: A washed NK-1148 strain treated pulp was prepared in the same manner as in Example 1. This was further treated with NaOH (NaOH amount added: 1.5 to pulp, pulp consistency: treating temperature: 70 0 C, treating time: 40 minutes).

After washed with water, it was treated with chlorine dioxide (amount added: 0.3 to pulp, pulp consistency: 10 treating temperature: 70 0 C, treating time: 2 hours) and then again washed with water. The brightness of the thus bleached pulp and the bleached pulp yield were measured.

As control, the oxygen/alkali treated pulp was directly treated by treating sequence of chlorine-NaOH-chlorine dioxide (for chlorine treatment, amount added: 2.1 to pulp, pulp consisteruy: 4 treating temperature: room temperature, treating time: 40 minutes; for NaOH treatment, amount added: 1.2 to pulp, pulp consistency: 10 treating temperature 70 0 C, treating time: 40 minutes; for chlorine dioxide treatment, amount added: 0.6 to pulp, pulp consistency: 10 treating temperature: 70°C, treating time: 2 hours), without being treated with NK-1148 strain.

-e -L I 1 thereto.

1I I I T- ;rP~Psi~?aerarr;s3aauaarr~--~~ 1 15 The results obtained are shown in Table 3 below.

Table 3 Comparison of Bleaching Sequences Total Effective Chlorine Amount Bleaching Sequence to pulp) O-F-E-D (embodiment of the 0.79 invention 0-C-E-D (control) 3.68 Table 3 continued Brightness Bleached Pulp Yield to r a d after heat- unbleached pulp) after air dried treated 85.9 81.5 94.1 86.1 81.7 94.2 Notes: O Oxygen/alkali treatment F NK-1148 strain treatment E Sodium hydroxide treatment C Chlorine treatment D Chlorine dioxide treatment As is obvious from the results as mentioned above, the following matters were confirmed. Precisely, in the control case of not having the microbial treatment, large amounts of chlorine- based chemicals must be used for obtaining a full-bleached pulp. As opposed to this, in accordance 16 with the embodiment of the present invention comprising combination of the microbial treatment, the chlorine-free chemical treatment and additionally the chlorine-based chemical treatment, a full-bleached pulp could be obtained easily even when a remarkably small amount of the chlorine-based chemical was used. In the case of the present invention, 78.5 reduction of the effective chlorine amount was possible, as compared with the control case.

Advantage of the Invention: In accordance with the present invention, since pulp can be bleached without use of chlorine-based chemicals and/or with use of a noticeably reduced amount of chlorinebased chemicals, generation of substances causing environmental pollution, such as dioxin, can completely be prevented and/or can noticeably be reduced. Therefore, effective bleaching of pulp is possible by the present invention without causing environmental pollution.

PLdU.LJL.l.1- UDC \0 r TAPPI Journal, 28, 564 (1974)).

17 Reference to Microorganism as Deposited under Rule 13.2: 1. NK-1148 a. Name and address of the organization in which the microorganism was deposited.

Name: Fermentation Research Institute, Agency of Industrial Science and Technology, Ministry of International Trade and Industry Address: 1-3, Higashi 1-chome, Tsukuba-shi, Ibaraki-ken 305, Japan b. Date of deposition of the microorganism in the organization of a.

May 23, 1987 c. Deposit number of the microorganism as rendered by the organization of a.

FERM BP-1859

M

Claims

1. A method of pulp bleaching comprising the steps of treating/bleaching the pulp with microorganism NK-1148 strain combined with a chemical chlorine-free treatment.

2. The method of pulp bleaching as claimed in claim i, which is further combined with light chlorine-based chemical treatment.

3. A method of pulp bleaching substantially as hereinbefore described with reference to the accompanying examples, but excluding control examples. DATED this 21st day of January 1994 KABUSHIKI KAISHA KOBE SEIKO SHO Patent Attorneys for the Applicant: F.B. RICE CO. -iv. .r4 C i 'Y Thi ii l 19 ABSTRACT Disclosed is a method of pulp bleaching by combination of microbial treatment and chlorine-free chemical treatment. Where no chlorine-based chemical is used in the method of the present invention, pulp can be bleached with a high efficiency, completely preventing generation of dioxin or the like. 1- INTERNATIONAL SEARCH REPORT International Application No PC' /JP92/00027 I. CLASSIFICATION OF SUBJECT MATTER (if several classification symbols apply, indicate all) 6 According to International Patent Classification (IPC) or to both National Classification and IPC Int. Cl 5 D21C9/10, C12S3/08 II. FIELDS SEARCHED Minimum Documentation Searched Classification System Classification Symbols IPC D21C9/10, C12S3/08 Documentation Searched other than Minimum Documentation to the Extent that such Documents are Included In the Fields Searched B III. DOCUMENTS CONSIDERED TO BE RELEVANT 9 Category Citation of Document, with Indication, where appropriate, of the relevant passages 1 Relevant to Claim No. 1 Y IJP, A, 2-259180 (Kobe Steel, Ltd.), 3 October 19, 1990 (19. 10. CA, A, 2012281 US, A, 5081027 X JP, A, 2-264087 (CIL Inc.), 1-2, 4 October 26, 1990 (26. 10. EP, A, 386888 AU, A, 9049321 NO, A, 9000631 PT, A, 93103 FI, A, 9000649 ZA, A, 9000897 BR, A, 9000589 X JP, A, 2-293486 (Ensorgzeite Osaquteio), 1-2, 4 December 4, 1990 (04. 12. EP, A, 395792 NO, A, 8903716 FI, A, 8902151 Y JP, A, 2-80687 (International Paper 1-2, 4 March 20, 1990 (20. 03. EP, A, 406617 NO, A, 9002756 AU, A, (057623 PT, A, 94450 CA, A, 2019411 FI, A, 9003166 ZA, A, 9004441 BR, A, 9002953 *Special categories of cited documents: '0 later document published after the International filing date or document defining the general state of the art which is not priority date and not in conflict with the application but cited to document sidered to be of particular relevancl state o the art which s no understand the principle or theory underlying the invention considered to be of particular relevance E" earier document but published on or after the international document of particular relevance; the claimed invention cannot fi"E" earlinger datocument but published on or after the international be considered novel or cannot be considered to involve an filing date inventive step document which may throw doubts on priority claim(s) or document of particular relevance; the claimed invention cannot which is cited- to establish the publication date of another b considered to involve an inventive step when the document citation or other special reason (as specified) is combined with one or more other such documents, such document referring to an oral disclosure, use. exhibition or combination being obvious to a person skilled in the art other means document member of the same patent family document published prior to the international filing date but later than the priority date claimed IV. CERTIFICATION Date of the Actual Completion of the International Search Date of Mailing of this International Search Report April 7, 1992 (07. 04. 92) April 28, 1992 (28. 04. 92) International Searching Authority Signature of Authorized Officer Japanese Patent Office Form PCT/ISA/210 (second sheet) (January 1985) a r EL Ii ~I1 obtained by culturing. Further, in the present invention, the r ~Z I I~m~z~rr*7m International Application No PCT/JP92/00027 FURTHER INFORMATION CONTINUED FROM THE SECOND SHEET Y JP, A, 63-500604 (Repligen Corp.), March 3, 1988 (03. 03. 88), PT, A, 82980 WO, A, 87/0564 AU, A, 6141286 FI, A, 871089 NO, A, 871061 EP, A, 231275 US, A, 4687745 BR, A, 8606775 CA, A, 1249783 YU, A, 125386 US, A, 4690895 1-2, 4 Y JP, A, 2-210085 (Sand AG.), August 21, 1990 (21. 08. EP, A, 373107 NO, A, 8904622 CA, A, 2003503 FI, A, 8905589 AU, A, 9056906 1-2, 4 OBSERVATIONS WHERE CERTAIN CLAIMS WERE FOUND UNSEARCHABLE This international search report has not been established in respect of certain claims under Article 17(2) lal for the following reasons: Claim numbers .because they relate to sublect matter not required to be searched by this Authority, namely: Claim numbers because they relate to parts of the international application that do not comply with the prescribed requirements to such an extent that no meaningful international search can be carried out, specifically: Claim numbers because they are dependent claims and are not drafted in accordance with the second and third sentences of F-T Rule 6,4(a). VI.[ OBSERVATIONS WHERE UNITY OF INVENTION IS LACKING 2 This International Searching Authority found mult:ple inventions in this international application as follows: 1. As all required additional search fees were timely paid by the applicant, this international search report covers all searchable claims of the international application As only some of the required additional search fees were timely paid by the applicant, this international search report covers only those claims of the international application for which fees were paid, specifically claims: No required additional search fees were timely paid by the applicant. Consequently, this international search report is restricted to the invention first mentioned in the claims; it is covered by claim numbers: As all searchable claims could be searched without effort lustifying an additional fee, the International Searching Authority did not invite payment of any additional fee. Remark on Protest The additional search fees were accompanied by applicant's protest. No protest accompanied the payment of additional search fees. Form PCT/ISA/210 (supplemental sheet (January 1985) International Application No PCT/JP9 2 00027 FURTHER INFORMATION CONTINUED FROM THE SECOND SHEET Y JP, A, 2-210086 (Sand 1-2, 4 August 21, 1990 (21. 08. EP, A, 373108 NO, A, 8904623 CA, A, 2003505 FI, A, 8905588 P,Y JP, A, 3-220388 (Kobe Steel, Ltd.), 1-4 September 27, 1991 (27. 09. 91), WO, A, 91/10773 JP, A, 3-213591 AU, A, 9170568 FI, A, 9104357 EP, A, 464221 P,Y JP, A, 3-40887 (International Paper 1-2, 4 February 21, 1991 (21. 02. 91), EP, A, 406617 NO, A, 9002756 V. OBSERVATIONS WHERE CERTAIN CLAIMS WERE FOUND UNSEARCHABLE This internatioi al search report has not been established in respect of certain claims under Article 17(2) (al for the following reasons: Claim numbers .because they relate to sublect matter not required to be searched by this Authority, namely: Claim numbers because they relate to parts of the international application that do not comply with the prescribed requirerents to such an extent that no meaningful international search can be carried out. specifically: Claim numbers because they are dependent claims and are not drafted in accordance with the second and third sentences of PCT Rule 6.4(a). OBSERVATIONS WHERE UNITY OF INVENTION IS LACKING 2 This International Searching Authority found multiple inventions in this international application as follows: i As all required additional search fees were timely paid by the applicant, this international search report covers all searchable Iclaims of the international application. 2.7 As only some of the required additional search fees were timely paid by the applicant, this international search report covers only those claims of the international application for which fees were paid, specifically claims: 3.n No required additional search fees were timely paid by the applicant. Consequently, this international search report is restricted to the invention first mentioned in the claims; it is covered by claim numbers: As all searchable claims could be searched without effort justifying an additional fee, the International Searching Authority did not invite payment of any additional fee. Remark on Protest The additional search fees were accompanied by applicant's protest. No protest accompanied the payment of additional search fees. Form PCT/ISA/210 (supplemental sheet (January 1985) L c C I I to 4 to pulp, pulp consistency: 10 treating International Application No. PCT/JP92 00027 FURTHER INFORMATION CONTINUED FROM THE SECOND SHEET AU, A, 9057623 PT, A, 94450 CA, A, 2019411 FI, A, 9003166 ZA, A, 9004441 BR, A, 9002953 P,Y JP, A, 3-174079 (Ensorgzeite Osaquteio), 1-2, 4 July 29, 1991 (29. 07. 91), EP, A, 430915 NO, A, 9005134 CA, A, 2030836 P,Y JP, A, 3-269188 (Oji Paper Co., Ltd.), 1-2, 4 November 29, 1991 (29. 11. 91), (Family: none) OBSERVATIONS WHERE CERTAIN CLAIMS WERE FOUND UNSEARCHABLE This international search report has not been established in respect of certain claims under Article 17(21 la) for the following reasons: 1.F Claim numbers because thpy relate to sublect matter not required to be searched by this Authority, namely: Claim numbers because they relate to parts of the international application that do not comply with the prescribed requirements to such an extent that no meaningful international search can be carried out, specifically: Claim numbers ,because they are dependent claims and are not drafted in accordance with the second and third sentences of PCT Rule 6.4(al. VI.] OBSERVATIONS WHERE UNITY OF INVENTION IS LACKING This International Searching Authority found multiple inventions in this international application as follows: As all required additional search fees were timely paid by the applicant, this international search report covers all searchable claims of the international application. As only some of the required additional search fees were timely paid by the applicant, this international search report covers only those claims of the international application for which fees were paid, specifically claims: No required additional search fees were timely paid by the applicant. Consequently, this international search report is restricted to the invention first mentioned in the claims; it is covered by claim numbers: As all searchable claims could be searched without effort justifying an additional fee, the International Searching Authority did not invite payment of any additional fee. Remark on Protest E The additional search fees were accompanied by applicant's protest. E No protest accompanied the payment of additional search fees. Form PCT/ISA/210 (supplemental sheet (January 1985) mpfimt-1PCT/JP 92/ 00 02 7 (IPG) hI t. CL' D21C9/10 ,C12S3/08 I PC D 2 1C9/1 0 C I12S3/08 Y JP, A, 2-259 180(~~ 3 1 9. 1 0A. 1 99 0 (19. 1 0. &CA, A, 2012281&US, A, 508 1027 JP, A, 2- 2 64 0 1 -2,4 4$L- .7y F),

26. 10,9. 1990(26. 10. &EP, A, 386 888&AU, A,90 49321 &NO, A, 9000631&PT, A, 93103 &FI,A,9000649&ZA,A,9000897 &BR, A, 9000589 JP, A, 2-293486 1 *V 1-2,4 4. 1 2A. 19 90 04. 1 2. &EP,A,395792&NOA, 8903716 Iff ZCD7h- f9 FTA BJ~t F L] j [u tE xi a W 5 -CS 0# 1'P j [EPRIN E-IT, W B rV. D a 0 7. 04. 9 2

28.04.92 H M I 0 P WM06ma 13,Bj 8 1 11 !8 El 9# 0 NAT (ISA/JP) j:vA- L PCT/JP 9 2 0 0 0 2 7 I No~att) &FI, A, 8902151 2 0. &E] A, 2-8 3 A. 1 9 40 J, A, 90 k, A, 20 k, A, 90 0 6 87 1- 2 ,4 90 66 1 576 194 044 0. 0 3. 9 0) &N6, A, 9 0 3&PT, A, 9 1&FI, A, 9 1&BR, A, 9 2756 4 0 3166 029 53 Z V~'tb k m~l l MI~ t B 1:flq 8 T, 3 x'Qjg at 1) Z 2 I. l ixn "31) S V1. 1 Ofl 9) Ili -14: 9) W -OA t- L Z L L 0) A 1 1 B L_ TA L 4~It <5 V4 75' I L t-A i 4rA iif~ t 9) [Al R)iAIPl N' I hR1 IM a)11t)t 3. i1nLrffti .~~~ilvr 3 ifl-tIi L ,Mit-< 14T-L11- rwRa 1 u~la~2 fliPCT/ISA/21OcilM-t-- (1985*- 1 J9 hi~ PCT/JP 9 2 /0 0 0 2 7 Y y y ply ply ply ply J P, A, 3. 3A~. &PT, A, &AU, A, &NO6, A, &US, A. &CA, A, &U 8, A, 3-5 9 88 8 29 61 4 87 1 4 68 1 24 4 69 0o06 04 V' 9 z~) (03. 03. 88 80&WC, A, 87/0564 1286&FI, A, 871089 061&EP, A, ,31275 7745&BR, A, 8606775 978 3&YU, A, 125386 0895 JP, A, 2-2 2 1. 8A~. 1 9 &EP, A, 3 7 &CA, A, 2 0 &AU, A, 9 0 1 0 9 0 3 1 0 3 56 o 8 5 V 79 V'lAY-7 (2 1. 08. 07&N), A, 8904622 503&FI, A, 8905589 9 06 0 8 6 F 7 -'i71) JP, A, 2-21 0 2 1. 8A. 1 99 0 &EP, A, 3 73 1 &CA, A, 2003 21. 08. 90 0 8&N6, A, 8 9 505&FI, A, 8 905588 3-2 13 59 1 1 -2,4 1 -2,4 1 -2,4 1 4 1 -2 4 1 -2,4 1 -2 4 JP, A, 3-22 27. 9A~. 1 99 &W6, A, 91 0 38 8 1( 2 107 7 7 0 9. 9 1) 3&JP9 A, &AU, A, 9170568FI, A, 9104357 A, 4 64 22 1 JP, A, 3-4 't 21. 2AJ. 19 &EP, A, 40 &AU, A, 90 &CA, A, 20 &Z A, A; 90 0 8 8 7 -f V A J- V 3 t -t 9 1 66 57 19 04 1. 02. 9 1 &N6, A, 90 0 3&P, A, 94 1&FI, A, 90 1&BR, A, 90 27 56 4 0 3166 02953 J P, 2 9. &EP &CA J P,

29. I L3-17 !~199 A, 4 30 A, 203 4 0 7 1 (29. 0 7. 9 15 &N6, A. 083 6 91) 1900 5134 A, 3 2 69 1 8 8(TfE~jt), I1A3.19 9 1( 29. 11. 9 1 -7 -tL) *AC/S/10V9J, (1985* 1 q)