CN102296474A - Biological treatment method for improving paper strength - Google Patents
Biological treatment method for improving paper strength Download PDFInfo
- Publication number
- CN102296474A CN102296474A CN2011102551927A CN201110255192A CN102296474A CN 102296474 A CN102296474 A CN 102296474A CN 2011102551927 A CN2011102551927 A CN 2011102551927A CN 201110255192 A CN201110255192 A CN 201110255192A CN 102296474 A CN102296474 A CN 102296474A
- Authority
- CN
- China
- Prior art keywords
- paper
- pulp
- strength
- syringaldehyde
- slurry
- Prior art date
- Legal status (The legal status is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the status listed.)
- Pending
Links
Abstract
The invention relates to a biological treatment method for improving paper strength, and belongs to the technical field of pulping and papermaking. The method comprises the following steps of: pulping and re-pulping old corrugated container (OCC) waste paper or unbleached kraft pulp (KP) to prepare pulp; adding laccase in an amount which is 8 to 12U/g of adding amount of absolute dry pulp, adding syringaldehyde and/or industrial lignin, stirring, and obtaining biologically treated paper pulp; and washing the biologically treated paper pulp by using water till the filtrate is colorless, performing papermaking, and drying. By using the characteristic that the aldehyde group of the syringaldehyde can be oxidized into carboxyl group, the hydrogen bond connection among fibers is strengthened, and the dry strength of the paper is improved; and two hydrophobic methyl groups of the syringaldehyde are grafted to the fibers, so that the wet strength of the paper is improved. Due to massive phenolic hydroxyl in the industrial lignin, phenolic oxygen free radicals are generated; and by cross-linking of the free radicals, the bonding strength among the fibers is strengthened, and the paper strength is improved.
Description
Technical field
The present invention relates to a kind of bioremediation of improving paper strength, particularly a kind of laccase that utilizes improves the method for paper strength performance in conjunction with syringaldehyde, industrial lignin pulp treatment, belongs to the pulp and paper technology field.
Background technology
Environmental pollution and energy shortage are the significant challenge that the mankind face.Adopting eco-friendly technology, making full use of renewable resource is that China implements the necessary top-priority key subjects of the strategy of sustainable development.The utilization of old corrugated container board (OCC) slurry increases year by year in China, but exists fibrous binding force poor, the shortcoming that the page bond strength is low.Not floating softwood kraft pulp (KP) is the typical chemical pulp of pulp and paper industry, have fiber length, eucaryotic cell structure characteristic of simple, for making usefulness such as brown paper, boxboard, plastics lining paper, wrapping paper and cardboard, the mechanical strength of product is to weigh the leading indicator of quality, the wet strength agent that adds contains the formaldehyde composition more at present, the PAE resin is the wet strength agent satisfactory for result of generally acknowledging at present, but that discovered in recent years is deposited in the process composition of organochlorine is higher.The strength of paper performance is to weigh the important indicator of paper quality, and the reinforcing agent that uses mostly is chemicals at present, and especially the use of the cationic Lauxite of Chang Yong wet strength agent, cationic melamine resin has caused harm to environment.Therefore, seek a kind of environment amenable method that can improve the wood fibre glue performance and become particularly urgent, development of biology is for addressing this problem the thinking that provides new.
Laccase is a kind of cupric polyphenol oxidase, can the catalytic oxidation phenols, the amine of armaticity and fatty etc., and reaction only needs airborne oxygen, and byproduct also has only water, is called as " green catalyst ".Publication number is the Chinese patent application of CN1986960A (application number 200510122490.3), and disclosing not float chemical pulp, semi-chemical pulp and OCC secondary stock is raw materials for production, produces the production process of corrugation boxboard and liner board.Owing to do not float chemical pulp, semi-chemical pulp and OCC paper pulp, make circulation plain boiled water in the paperboard production process contain fiber fines, sterol ester, rosin acid, lignan (LIGNAN) and the lignin fragment etc. of higher amount.These materials have a large amount of anion, i.e. anionic trash.And the high level anionic trash can influence the additive effect of traditional paper making intensifier, improves production cost, also can cause environmental pollution.This invention is to use the oxidation of laccase catalysis wood fibre, on the wood fibre surface, produce the phenol oxygen radical,, improve interfibrous bond strength by the free radical condensation, thereby improve physical strength, particularly cardboard ring crush intensity and the wet ring crush intensity of corrugated case paperboard and liner board.
Syringaldehyde is the substrate of laccase, can obtain by organic solvent extracting or alkali extracting in plant material, even can extract in papermaking wastewater, have be easy to get, characteristics that toxicity is little.
Industrial lignin is the main component of paper-making pulping waste liquid, comprise alkali lignin and lignosulphonates, alkali lignin comes from soda processes or sulphate chemical pulping process, lignosulphonates are from acid polishing, be the catabolite of lignin macromolecule, contain the active group phenolic hydroxyl group of a large amount of laccases, the whole world produces 3,000 ten thousand tons industrial lignin every year approximately, have only about 6% (mainly being lignosulphonates) to be recovered at present, come into the market as byproduct.
Summary of the invention
The present invention is directed to the deficiencies in the prior art, a kind of bioremediation of improving paper strength is provided.
Summary of the invention
The present invention utilizes laccase and syringaldehyde, industrial lignin to handle the OCC slurry or do not float dry tensile strength, wet tensile (strength) and the dried bursting strength that sulfate pulp is improved paper, can be used to produce corrugation boxboard and liner board.
Discover that through the inventor phenolic compound and industrial lignin all can produce the phenol oxygen radical under the laccase effect, the lignin that string surface in the paper pulp exists also can produce free radical, therefore, under the effect of laccase, fiber, industrial lignin and phenolic compound can be by the cross-linking reactions between the free radical, increase the adhesion between the fiber, thereby improve the strength of paper performance.Use the laccase catalysis technique, some compound is grafted on makes fiber " functionalization " on the fiber, give the physical and chemical performance that fiber upgrades.
This method can keep original important physics of fiber and chemical property, and technology is simple, does not pass through violent chemical reaction, belongs to the non-destructive reaction; Be a kind of eco-friendly " green technology ".
Detailed Description Of The Invention
A kind of bioremediation of improving paper strength, step is as follows:
(1) with old corrugated container board waste paper or do not float softwood kraft pulp and carry out pulping, pull an oar again to beating degree be 40 ° of SR～50 ° SR, make solid-liquid ratio and be 5～8: 100 slurry;
(2) the slurry pH that makes of pacing rapid (1) is 4～7, addition by 8～12U/g oven dry stock adds laccase, the syringaldehyde and/or 0.1%～0.2% industrial lignin that add oven dry stock weight 0.2%～0.5% then, under 20 ℃～45 ℃ condition, stir 1～2h, the paper pulp after must carrying out a biological disposal upon;
(3) paper pulp is washed with water to filtrate and is colourless after the biological treatment that step (2) is made, and carries out page then and manufactures paper with pulp, and oven dry promptly gets paper.
Pulping in the described step (1), size degradation concentration 6～10wt%.
Old corrugated container board waste paper in the described step (1) carries out pulping, also comprises pulp sifting and washing step.If do not float the KP slurry, can be without screening and washing.
Solid-liquid ratio in the described step (1) is meant the ratio of oven dry stock weight and total liquid volume in the slurry, and unit is g/ml.
Stirring in the described step (2) also comprises bubbling air in slurry, and the slurry dissolved oxygen amount is remained on more than the 5mg/L.
U in the described step (2) is meant that using pH value is the ABTS (2 that 4.5 sodium acetate buffer solution is prepared 0.5mmol/l, 2-connection nitrogen-two (3-ethyl-benzothiazole-6-sulfonic acid) di-ammonium salts) solution, the needed laccase amount of per minute oxidation 1 μ mol ABTS is defined as unit of activity, i.e. a 1U.
Drying condition in the described step (3) is 90～95 ℃.
The lignin acidizing separation that extracts in the black liquid of described industrial lignin from soda pulping process factory, perhaps acid polishing gained lignosulphonates.
Beneficial effect of the present invention:
1, the present invention utilizes the aldehyde radical of syringaldehyde can be oxidized to the characteristic of carboxyl, the content of carboxyl in the fiber is increased, the hydrogen bond of having strengthened between the fiber connects, improved the dry strength of paper, simultaneously, two hydrophobicity methyl that syringaldehyde has are grafted on the fiber, help improving the wet strength of paper.
2, the present invention is by utilizing the industrial lignin that extracts in the papermaking wastewater, the syringaldehyde substrate as laccase, under the catalysed oxidn of laccase, produce the phenol oxygen radical, the free radical that produces with the fiber surface lignin takes place crosslinked, the covalent bond that has increased between the fiber connects, and has strengthened the strength of paper performance.
The specific embodiment
The present invention will be further described below in conjunction with embodiment, but institute of the present invention protection domain is not limited thereto.
Laccase described in the embodiment is the laccase of NS51003 available from the article number that letter (China) Investment Co., Ltd of Novi produces, and syringaldehyde is pure for analyzing, and alkali lignin and lignosulphonates are the commercially available prod, and purity is technical grade.
Embodiment 1
A kind of bioremediation of improving paper strength, step is as follows:
(1) OCC waste paper is carried out pulping, size degradation concentration 10%, after screening and the washing, pull an oar again be 45 ° of SR to beating degree after, the preparation solid-liquid ratio is the slurry of 5: 100 (g/ml);
(2) use 0.2M H
2SO
4The slurry pH that pacing rapid (1) makes is 4.5, the addition of pressing the 10U/g oven dry stock adds laccase, it is divided into 6 groups then, 5 groups of syringaldehydes of 0.1%, 0.2%, 0.3%, 0.4%, 0.5% that add oven dry stock weight respectively wherein, the control slurry group does not add syringaldehyde, at 45 ℃, under the condition of slurry dissolved oxygen amount 〉=5mg/L, stir 1h, the back paper pulp of must carrying out a biological disposal upon;
(3) paper pulp is washed with water to colourlessly after the biological treatment that step (2) is made, and carries out page then and manufactures paper with pulp, and after 95 ℃ of oven dry, detects.
Blank: the preparation method as above, difference is, does not add laccase, syringaldehyde.
Control slurry: the preparation method as above, difference is, does not add syringaldehyde.
Detection method:
Measure the dried tensile index and the burst index of paper according to GB/T 453-2002 and GB/T 454-2002 method.When measuring the wet tensile index of paper according to GB/T 453-2002, pattern is measured after at room temperature soaking 1h with distilled water.Pattern is prepared as follows before measuring:
Paper slip to be determined is dangled to not dripping, be tiled on the filter paper, gently press with filter paper above and draw paper slip moisture, use second filter paper again instead and gently press, anhydrous the appearing in filter paper surface this moment can be measured.The method is through multiple authentication, and l Water Paper bar moisture is consistent substantially.
12 paper slips that four handsheets are all got in above strength test, each testing site carry out tensile strength mensuration, get its mean value.Burst index is the mean value of 4 data.
The result is as shown in table 1.
Table 1
Analyze: in laccase/syringaldehyde system for handling, different syringaldehyde consumptions are to the humidification difference of paper pulp.As can be seen from Table 1, paper pulp is after laccase and syringaldehyde processing, and strength character all is improved.When the syringaldehyde consumption was 0.4%, the dried tensile index of gained paper can rise to 33.16Nm/g (having improved 10.3%) from 30.07Nm/g, and wet tensile index rises to 1.25Nm/g (having improved 35.8%) from 0.92Nm/g, and dried burst index then can be from 1.77kPam
2/ g is increased to 2.12kPam
2/ g (having improved 19.8%).
Embodiment 2
As improving the bioremediation of paper strength as described in the embodiment 1, difference is, when adding the different amounts syringaldehyde, has added 0.2% Industrial Alkali Lignin (oven dry stock relatively), reacts 1 hour.
Blank: the preparation method as above, difference is, does not add laccase, syringaldehyde and alkali lignin.
Control slurry: the preparation method as above, difference is, does not add syringaldehyde and alkali lignin.
Detection method is with embodiment 1.
The result is as shown in table 2.
Table 2
Analyze: when the alkali lignin that adds 0.2%, add the syringaldehydes of different amounts, all can improve the strength of paper performance in various degree.The table of comparisons 1 adds the syringaldehyde of isodose, when additionally adding 0.2% industrial lignin, can obtain higher paper strength, especially wet tensile (strength).When adding 0.2% syringaldehyde and alkali lignin simultaneously than independent adding 0.4% syringaldehyde to the page tensile strength to improve effect good, and the cost of Industrial Alkali Lignin is more much lower than the price of syringaldehyde, therefore can use industrial lignin to replace a certain amount of syringaldehyde to use.In addition, when the syringaldehyde consumption is 0.3%, add 0.2% alkali lignin, the dried tensile index of paper, wet tensile index and dried burst index reach maximum, and the relative comparison slurry has improved 12.0%, 42.1% and 21.7% respectively.
Embodiment 3
As improving the bioremediation of paper strength as described in the embodiment 2, difference is, add 0.2% syringaldehyde in the step (2) earlier and be under 25 ℃ the condition reaction after 1 hour, added 0.2% Industrial Alkali Lignin again and be under 25 ℃ the condition reaction 0.5 hour in temperature in temperature.
Blank: the preparation method as above, difference is, does not add laccase, syringaldehyde and alkali lignin.
Control slurry: the preparation method as above, difference is, does not add syringaldehyde and alkali lignin.
Detection method is with embodiment 1.
The result is as shown in table 3.
Table 3
Analyze: compare with control slurry, the dried burst index of paper, dried tensile index and wet tensile index have improved 17.9%, 16.6% and 52.6% respectively.
Embodiment 4
As improving the bioremediation of paper strength as described in the embodiment 1, difference is, is raw material with OCC, in step (1) gained slurry, adds laccase 10U/g, syringaldehyde 0.2% and lignosulphonates 0.2% (all relative oven dry stock) simultaneously.Slurry pH is 4.5,40 ℃.
Blank: the preparation method as above, difference is, does not add laccase, syringaldehyde and lignosulphonates.
Control slurry: the preparation method as above, difference is, does not add syringaldehyde and lignosulphonates.
Detection method is with embodiment 1.
The result is as shown in table 4.
Table 4
Analyze: the relative comparison slurry, the dried tensile index of paper is increased to 31.1Nm/g by 27.4Nm/g, and wet tensile index improves 33.3%, and dried burst index improves 7.6%.
Embodiment 5
As improving the bioremediation of paper strength as described in the embodiment 1, difference is, is raw material with the KP slurry, in step (1) gained slurry, adds laccase 10U/g simultaneously, and alkali lignin 0.2%, slurry pH are 6,25 ℃ of room temperatures.
Blank: the preparation method as above, difference is, does not add laccase and alkali lignin.
Control slurry: the preparation method as above, difference is, does not add alkali lignin.
Detection method is with embodiment 1.
The result is as shown in table 5.
Table 5
Analyze: when using laccase/alkali lignin to handle, blank relatively sample, the dried tensile index of paper can be increased to about 68Nm/g from 64Nm/g, and wet tensile index can improve 94%, dried burst index improves DeGrain.
Embodiment 6
As described in embodiment 3, different is that paper pulp is not starched for floating needlebush KP, and industrial lignin is lignosulphonates.
Embodiment 7
As described in embodiment 5, different is that paper pulp is not starched for floating needlebush KP, and industrial lignin is lignosulphonates.
Claims (6)
1. bioremediation of improving paper strength, step is as follows:
(1) with old corrugated container board waste paper or do not float KP slurry and carry out pulping, pull an oar again to beating degree be 40 ° of SR～50 ° SR, make solid-liquid ratio and be 5～8: 100 slurry;
(2) the slurry pH that makes of pacing rapid (1) is 4～7, addition by 8～12U/g oven dry stock adds laccase, the syringaldehyde and/or 0.1%～0.2% industrial lignin that add oven dry stock weight 0.2%～0.5% then, under 20 ℃～45 ℃ condition, stir 1～2h, the paper pulp after must carrying out a biological disposal upon;
(3) paper pulp is washed with water to filtrate and is colourless after the biological treatment that step (2) is made, and carries out page then and manufactures paper with pulp, and oven dry promptly gets paper.
2. bioremediation as claimed in claim 1 is characterized in that, the pulping in the described step (1), size degradation concentration 6～10wt%.
3. bioremediation as claimed in claim 1 is characterized in that, the old corrugated container board waste paper in the described step (1) carries out pulping, also comprises pulp sifting and washing step.
4. bioremediation as claimed in claim 1 is characterized in that, the stirring in the described step (2) also comprises bubbling air in slurry, and the slurry dissolved oxygen amount is remained on more than the 5mg/L.
5. bioremediation as claimed in claim 1, it is characterized in that, U in the described step (2) is meant that using pH value is that 4.5 sodium acetate buffer solution is prepared 2 of 0.5mmol/l, 2-connection nitrogen-two (3-ethyl-benzothiazole-6-sulfonic acid) di-ammonium salts solution, the needed laccase amount of per minute oxidation 1 μ mol ABTS is defined as unit of activity, i.e. a 1U.
6. bioremediation as claimed in claim 1 is characterized in that, the drying condition in the described step (3) is 90～95 ℃.
Priority Applications (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| CN2011102551927A CN102296474A (en) | 2011-08-31 | 2011-08-31 | Biological treatment method for improving paper strength |
Applications Claiming Priority (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| CN2011102551927A CN102296474A (en) | 2011-08-31 | 2011-08-31 | Biological treatment method for improving paper strength |
Publications (1)
| Publication Number | Publication Date |
|---|---|
| CN102296474A true CN102296474A (en) | 2011-12-28 |
Family
ID=45357139
Family Applications (1)
| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| CN2011102551927A Pending CN102296474A (en) | 2011-08-31 | 2011-08-31 | Biological treatment method for improving paper strength |
Country Status (1)
| Country | Link |
|---|---|
| CN (1) | CN102296474A (en) |
Cited By (5)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN102817286A (en) * | 2012-05-24 | 2012-12-12 | 湖北工业大学 | Method for manufacturing formaldehyde-free straw fiber board |
| CN104213448A (en) * | 2014-08-28 | 2014-12-17 | 华南理工大学 | Laccase/glutamic acid-based biological treatment method for inhibiting strength degradation of regenerated fibers |
| CN107401087A (en) * | 2017-05-31 | 2017-11-28 | 浙江哲丰新材料有限公司 | A kind of dab glassine paper of biological treatment and preparation method thereof |
| CN109811585A (en) * | 2019-04-15 | 2019-05-28 | 齐鲁工业大学 | A method of improving boxboard strength character |
| CN110935129A (en) * | 2019-11-07 | 2020-03-31 | 桂林理工大学 | Application of syringaldehyde as redox mediator for degrading stilbestrol by laccase and method for improving degradation rate of stilbestrol degraded by laccase |
Citations (2)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN1786339A (en) * | 2005-11-18 | 2006-06-14 | 山东轻工业学院 | Method for improving mechanical wood pulp fibre performance |
| CN1986960A (en) * | 2005-12-21 | 2007-06-27 | 天津科技大学 | Technology for improving corrugated box board paper strength using laccase treating OCC pulp |
-
2011
- 2011-08-31 CN CN2011102551927A patent/CN102296474A/en active Pending
Patent Citations (2)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN1786339A (en) * | 2005-11-18 | 2006-06-14 | 山东轻工业学院 | Method for improving mechanical wood pulp fibre performance |
| CN1986960A (en) * | 2005-12-21 | 2007-06-27 | 天津科技大学 | Technology for improving corrugated box board paper strength using laccase treating OCC pulp |
Non-Patent Citations (3)
| Title |
|---|
| 刘娜等: "漆酶/丁香酸甲酯改善未漂硫酸盐浆纤维特性的EPR研究", 《中国造纸学报》, vol. 24, no. 1, 31 March 2009 (2009-03-31), pages 11 - 15 * |
| 周生飞等: "漆酶-天然介体体系用于硫酸盐竹浆漂白", 《纸和造纸》, vol. 30, no. 7, 31 July 2011 (2011-07-31), pages 48 - 51 * |
| 石淑兰等: "漆酶和漆酶/介体处理提高未漂化学木浆湿强度的研究", 《中国造纸》, vol. 25, no. 2, 28 February 2006 (2006-02-28), pages 8 - 12 * |
Cited By (8)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN102817286A (en) * | 2012-05-24 | 2012-12-12 | 湖北工业大学 | Method for manufacturing formaldehyde-free straw fiber board |
| CN104213448A (en) * | 2014-08-28 | 2014-12-17 | 华南理工大学 | Laccase/glutamic acid-based biological treatment method for inhibiting strength degradation of regenerated fibers |
| CN107401087A (en) * | 2017-05-31 | 2017-11-28 | 浙江哲丰新材料有限公司 | A kind of dab glassine paper of biological treatment and preparation method thereof |
| CN107401087B (en) * | 2017-05-31 | 2019-07-26 | 浙江哲丰新材料有限公司 | A kind of dab glassine paper of biological treatment and preparation method thereof |
| CN109811585A (en) * | 2019-04-15 | 2019-05-28 | 齐鲁工业大学 | A method of improving boxboard strength character |
| CN109811585B (en) * | 2019-04-15 | 2021-08-20 | 齐鲁工业大学 | Method for improving strength performance of cardboard paper |
| CN110935129A (en) * | 2019-11-07 | 2020-03-31 | 桂林理工大学 | Application of syringaldehyde as redox mediator for degrading stilbestrol by laccase and method for improving degradation rate of stilbestrol degraded by laccase |
| CN110935129B (en) * | 2019-11-07 | 2021-07-09 | 桂林理工大学 | Application of syringaldehyde as redox mediator for degrading stilbestrol by laccase and method for improving degradation rate of stilbestrol degraded by laccase |
Similar Documents
| Publication | Publication Date | Title |
|---|---|---|
| Zhu et al. | Sulfite pretreatment (SPORL) for robust enzymatic saccharification of spruce and red pine | |
| RU2401351C1 (en) | Modified fibres of sulfate cellulose | |
| Zhu et al. | Integrated production of nano-fibrillated cellulose and cellulosic biofuel (ethanol) by enzymatic fractionation of wood fibers | |
| CN108505372B (en) | A method of low gram weight and high strength degree craft paper is produced using domestic waste paper | |
| Ma et al. | Influence of TEMPO-mediated oxidation on the lignin of thermomechanical pulp | |
| CN102296474A (en) | Biological treatment method for improving paper strength | |
| Hunt et al. | A biopulping mechanism: creation of acid groups on fiber | |
| Chen et al. | Modification of old corrugated container pulp with laccase and laccase–mediator system | |
| Aracri et al. | Enhancing the effectiveness of a laccase–TEMPO treatment has a biorefining effect on sisal cellulose fibres | |
| CN103726396A (en) | Production method of high stiffness heat transfer raw paper | |
| CN102061642A (en) | Method for improving intensity of corrugated medium paper and paperboard by using pulping waste liquor of high-yield pulp | |
| US8241461B1 (en) | Wet strength resins derived from renewable resources | |
| CN105672053B (en) | A kind of spool fiber board | |
| Chen et al. | Fiber characterization of old corrugated container bleached pulp with laccase and glycine pretreatment | |
| CN1986960A (en) | Technology for improving corrugated box board paper strength using laccase treating OCC pulp | |
| CN103898789A (en) | Bio enzyme preparation for improvement of paper forming strength of alkaline peroxide mechanical pulp (APMP) and application thereof | |
| MX2012013267A (en) | Process for reclying waste paper, product obtained therefrom and its uses. | |
| CN104213448A (en) | Laccase/glutamic acid-based biological treatment method for inhibiting strength degradation of regenerated fibers | |
| Hou et al. | Application of alkaline ionic liquids in the pretreatment process of eucalyptus kraft pulping | |
| CN101654883B (en) | Biological processing method for preventing strength of regenerated plant fiber from being reduced | |
| CN109024038A (en) | The modification pulping process and modified slurry and papermaking process of secondary stock | |
| CN104695264B (en) | Second hand cases paperboard ink and gluing thing synchronization process enzyme compositions and application thereof | |
| CN101935120B (en) | Recycle method of pulping effluent of wheat straw chemi-mechanical pulp | |
| CN102251433A (en) | Method for preparing paper | |
| Zhang et al. | Fiber modification of OCC pulp with laccase and natural mediator system |
Legal Events
| Date | Code | Title | Description |
|---|---|---|---|
| C06 | Publication | ||
| PB01 | Publication | ||
| C10 | Entry into substantive examination | ||
| SE01 | Entry into force of request for substantive examination | ||
| C12 | Rejection of a patent application after its publication | ||
| RJ01 | Rejection of invention patent application after publication |
Application publication date: 20111228 |