WO1994009057A1 - Procede pour la modification d'un materiau lignocellulosique, en phase vapeur - Google Patents

Procede pour la modification d'un materiau lignocellulosique, en phase vapeur Download PDF

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Publication number
WO1994009057A1
WO1994009057A1 PCT/GB1993/001576 GB9301576W WO9409057A1 WO 1994009057 A1 WO1994009057 A1 WO 1994009057A1 GB 9301576 W GB9301576 W GB 9301576W WO 9409057 A1 WO9409057 A1 WO 9409057A1
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WO
WIPO (PCT)
Prior art keywords
lignocellulosic
substitute sheet
density
modification
modified
Prior art date
Application number
PCT/GB1993/001576
Other languages
English (en)
Inventor
David George Rogers
Michael Patrick Boyle
Jean-Pierre Fouche
Original Assignee
David George Rogers
Michael Patrick Boyle
Fouche Jean Pierre
Priority date (The priority date 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 date listed.)
Filing date
Publication date
Application filed by David George Rogers, Michael Patrick Boyle, Fouche Jean Pierre filed Critical David George Rogers
Publication of WO1994009057A1 publication Critical patent/WO1994009057A1/fr

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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
    • D21C1/00—Pretreatment of the finely-divided materials before digesting
    • D21C1/04—Pretreatment of the finely-divided materials before digesting with acid reacting compounds
    • B—PERFORMING OPERATIONS; TRANSPORTING
    • B27—WORKING OR PRESERVING WOOD OR SIMILAR MATERIAL; NAILING OR STAPLING MACHINES IN GENERAL
    • B27K—PROCESSES, APPARATUS OR SELECTION OF SUBSTANCES FOR IMPREGNATING, STAINING, DYEING, BLEACHING OF WOOD OR SIMILAR MATERIALS, OR TREATING OF WOOD OR SIMILAR MATERIALS WITH PERMEANT LIQUIDS, NOT OTHERWISE PROVIDED FOR; CHEMICAL OR PHYSICAL TREATMENT OF CORK, CANE, REED, STRAW OR SIMILAR MATERIALS
    • B27K3/00—Impregnating wood, e.g. impregnation pretreatment, for example puncturing; Wood impregnation aids not directly involved in the impregnation process
    • B27K3/02—Processes; Apparatus
    • B27K3/0271—Vapour phase impregnation
    • B—PERFORMING OPERATIONS; TRANSPORTING
    • B27—WORKING OR PRESERVING WOOD OR SIMILAR MATERIAL; NAILING OR STAPLING MACHINES IN GENERAL
    • B27K—PROCESSES, APPARATUS OR SELECTION OF SUBSTANCES FOR IMPREGNATING, STAINING, DYEING, BLEACHING OF WOOD OR SIMILAR MATERIALS, OR TREATING OF WOOD OR SIMILAR MATERIALS WITH PERMEANT LIQUIDS, NOT OTHERWISE PROVIDED FOR; CHEMICAL OR PHYSICAL TREATMENT OF CORK, CANE, REED, STRAW OR SIMILAR MATERIALS
    • B27K3/00—Impregnating wood, e.g. impregnation pretreatment, for example puncturing; Wood impregnation aids not directly involved in the impregnation process
    • B27K3/34—Organic impregnating agents
    • B27K3/346—Grafting onto wood fibres
    • C—CHEMISTRY; METALLURGY
    • C08—ORGANIC MACROMOLECULAR COMPOUNDS; THEIR PREPARATION OR CHEMICAL WORKING-UP; COMPOSITIONS BASED THEREON
    • C08H—DERIVATIVES OF NATURAL MACROMOLECULAR COMPOUNDS
    • C08H8/00—Macromolecular compounds derived from lignocellulosic materials
    • B—PERFORMING OPERATIONS; TRANSPORTING
    • B27—WORKING OR PRESERVING WOOD OR SIMILAR MATERIAL; NAILING OR STAPLING MACHINES IN GENERAL
    • B27K—PROCESSES, APPARATUS OR SELECTION OF SUBSTANCES FOR IMPREGNATING, STAINING, DYEING, BLEACHING OF WOOD OR SIMILAR MATERIALS, OR TREATING OF WOOD OR SIMILAR MATERIALS WITH PERMEANT LIQUIDS, NOT OTHERWISE PROVIDED FOR; CHEMICAL OR PHYSICAL TREATMENT OF CORK, CANE, REED, STRAW OR SIMILAR MATERIALS
    • B27K2200/00—Wooden materials to be treated
    • B27K2200/15—Pretreated particles or fibres

Definitions

  • Acet lated wood has been found to possess a high degree of dimensional stability and good decay resistance. Previous attempts at commercial process have been found to be expensive to attract industry and the processes have been used with wood of lumber thickness liquid phase treatments have tendered to cause problems with the large excess after acetylation of the acetylating solution.
  • This process deals specifically with the Acetylation of Lignocellulosic materials in their vapour phase using Lignocellulosic fibre, chip, shred, and veneer material.
  • the Lignocellulosic material can then be resinated and pressed or moulded or extracted into all manner of products in an acceptable industrial scale.
  • the primary objective of this industrial process scale invention is to present a process for large scale industrial continuous production use for acetylating all types of Lignocellulosic materials by vapour phase in a cost effective manner.
  • the process does not use complex mixtures, the equipment is simple and user friendly and the materials of construction are non exotic easily fabricated thus not. having the disadvantages of the prior inventions.
  • the process will continuously improve the (Linear % Swell %) stability I.B.S., M.O.R. , and M.O.E. of the finished product, along with biological resistance to all manner of Lignocellulosic materials, in fibre, chip, shred and veneer form.
  • the present invention is believed to have several advantages over prior inventions in modification of wood its derivative materials, or other Lignocellulosic materials.
  • SUBSTITUTE SHEET This process does not use a co-solvent or added catalyst and its most simple and user friendly to operate.
  • the Lignocellulosic material is dried to its mean average using centrifugal filtration techniques. Existing drying facilities when centrifugal techniques are not used. Plume elimination to atmosphere when centrifugal techniques are used.
  • the material is treated counter current wise with precise amount of Acetic Anhydride vapour for a very short period of time. The time is adapted to suit the material and final specification required. Excess acetylation solution is removed and recovered. The continuous chamber then completes the reaction and dries the Lignocellulosic material.
  • the specification of the final product is related to its weight gain for the specific use required.
  • the Industrial Scale Process for the modification of Lignocellulosic material relates to the chemical modification of Lignocellulosic materials by Acetic Anhydride in vapour phase. This process in an industrial scale relates to the modification of all Lignocellulosic materials to obtain a high degree of moisture resistance, stability and greater resistance to infestation.
  • the Industrial Scale Process can also deal with other Lignocellulosic materials such as :-
  • Lignocellulosic material There are desirable and undesirable properties within Lignocellulosic material.
  • the undesirable properties have limited their use for many products.
  • Physical and chemical properties of Lignocellulosic materials are the result of the structure of the cell wall components both individually and collectively.
  • wood changes its dimension with a changing moisture content. This is due to the cell wall polymers containing Hydroxyl and other oxygen containing groups. These groups attract moisture through hydrogen bonding. This moisture take up, swells the cell wall and therefore the wood expands until the cell wall becomes saturated with water. Beyond the saturation point the water is free water in the structure and as such does not take part in further expansion. This process is somewhat reversible i.e. as moisture is lost, shrinkage will occur.
  • Lignocellulosic materials are bio degradable, organisms do recognize the polysacharides in the cell wall and they have very specific enzyme systems which are capable of changing these polymers into digestible units.
  • the high molecule or weight cellulose is the primary element responsible for strength in wood. The strength is lost as this polymer undergoes biological degradation through oxidation hydrolysis and dehydration reactions.
  • the process is too large to suit existing industrial restraints. Is too time consuming.
  • the process is too complicated, is excessively expensive, special drying facilities required, or the process inputs undesirable properties to the product.
  • Lignocellulosic fibres, chip, shred, of all types and sizes practically or totally dried by continuous filtration or otherwise to mean average moisture content and below, are transported at temperature into a modifier either in continuous configuration or batch (1), (2).
  • Anhydride vapour enters the modifier (3) at the opposite end or other and by plug formation technique in counter current fashion or other the anhydride vapour passes over and through the material and after a very short time (minutes) sufficient impregnation has taken place.
  • Acetic Acid in the form of vapour is removed to (5) for further vaporization (7), using known ketene route.
  • Time scale for penetration depends on material being a fibre, veneer, board, structural member, chip or shred, to the degree of modification required but in minutes as apposed to hours.
  • the process can use waste materials in all of the (1) to (7) areas and take a waste material into an area of added value.
  • the main attributes to this process development is a greatly simplified Acetic Anhydride in vapour phase process for Lignocellulosic materials to give dimensional stability and biological resistance with speed of operation.
  • Lignocellulosic are naturally occurring materials consisting mainly of cellulose, hemicellulose, and lignin. Wood is one of the most commonly used of the lignocellulosics, and has traditionally been used as timber for constructional purposes. However, in the preparation of the timber much waste was produced. A means of converting this waste to a useful product was found in the form of composites, such as particle board.
  • particle board There are various types of particle board ranging from water board, strand board and orientated strand board through chip board to fibre board. Nearly all of these boards are conventionally produced by the dry forming process, resinating the almost dry wood particles and pressing to give a sheet product. The product is mainly flat sheet but some moulded products are also manufactured. The alternative is to wet form the sheet, either flat or moulded followed by pressing. This alternative method is normally only applied to fibre board.
  • SUBSTITUTE SHEET The products formed by these procedures are widely used for construction purposes plus a variety of other end uses. There is one major drawback to all of these products, which is their lack of water resistance. As a consequence very few are able to be used for external use. However, it is possible to improve the water resistance of these products by chemical modification of the Lignocellulosic substrate.
  • the chemical modification can be either a pretreatment or post treatment, depending on the desired property enhancement required and the type of product.
  • a further consequence of improving the water resistance is found to be an improvement of the strength properties of the product which is maintained after being subjected to high moisture environments. This is even observed after submersion in water, to have no detrimental effect on water resistance or strength properties.
  • Lignocellulosic materials are potentially very reactive due to the abundance of functional groups on the polymeric hydroxyl group.
  • the presence and availability of the hydroxyl group gives Lignocellulosics material their strength and versatility, but is also the reason for the problems that arise with lignocellulosics.
  • the hydroxyl groups are in such large numbers that hydrogen bonding within and between the polymeric species occurs throughout the material. It is hydrogen bonding which binds wood together and leads to its strength but it is hydrogen bonding which allows hydrophilic substances like water to enter the structure and interact with the polymers and alter the properties of the lignocellulosic material. This gives rise to other problems such as micro-biological decay. If the natural reactivity of Lignocellulosics can be utilized to enhance the properties the resultant material would be superior in terms of performance and versatility.
  • association by interaction to give covalent bond formation.
  • the most common type of covalent bond formation that is possible with Lignocellulosics is the interaction with the abundant hydroxyl groups. Hydroxyl groups are available on all the polymeric species that occur in Lignocellulosics, i.e. on the cellulose, hemicellulose, and lignin, plus also the extractives.
  • R-C 0 Ligcell-0 R ⁇ ⁇ /
  • Lignocellulosic substrates which are known to react with chemically modifying reagents to produce materials with enhanced properties.
  • simple modifying agents can be any material that will interact with the Lignocellulosic substrate. This would included any material that could form some weak interaction with any part of the Lignocellulosic. This type of modification can easily be reversed by simple solvent exposure, i.e. by leaching.
  • SUBSTITUTE SHEET These reagents can be either monofunctional or difunctional depending on the desired properties of the end product.
  • the modifying reagents can be used with or without solvents and with or without catalysts.
  • catalysts triethylamine ,. diazobicycl(2, 2, 2,)octane n-methyl pyrrolidinone
  • the modifying agents as outlined above are chosen because of the reactivity with the hydroxyl groups of the lignocellulosic material.
  • These modifying agents give a carbamate ester linkage to the substrate.
  • the type of solvents tend to be commercial industrial solvents, typically paint solvents.
  • the acetylated material will then be pressed into boards to give a superior medium density fibre board, or into mouldable products.
  • Lignocellulosic materials are generally susceptible to degradation and water impregnation, which ultimately affect the performance.
  • Chemically modified Lignocellulosic material can be designed and engineered so that it is not susceptible to either of the above, i.e. degradation, or water impregnation, and included in the Industrial Process
  • the composite materials formed from a Lignocellulosic which has been chemically modified is superior to the unmodified composite in many respects.
  • the strength can be increased dramatically.
  • the internal bond strength can be increased five fold, coupled with a doubling of the modulus of rupture. Similar results are obtainable with other composites such as medium density fibre board from this Process.
  • the resistance to swelling can be reduced to very low values, so that the material becomes compatible with metal veneers and other similar materials that are not affected by water from this process.
  • Chemical modification makes the material resistant to biological degradation, and resistance to ultra violet degradation can be engineered into the product, with this process.
  • SUBSTITUTE SHEET Fire resistance is another quality that can be designed into the product when produced by chemical modification and is also non- leachable, unlike conventional processes from within this process.
  • the process is multipurpose for all Lignocellulosic materials as listed.
  • N NON ACETYLATED
  • Chemical modification of Lignocellulosic materials can be carried out to the level required to achieve the desired end product.
  • the end product can have the desired properties designed and engineered into it by a combination of modifications.
  • Chemical modification treats a Lignocellulosic as a mixture of polymeric materials which can be altered to suit the end purpose.
  • a chemically modified material can have reactivity towards specific agents designed into it.
  • Lignocellulosic materials In short chemical modification takes Lignocellulosic materials from being a low grade material into the area of high grade polymers.

Landscapes

  • Life Sciences & Earth Sciences (AREA)
  • Chemical & Material Sciences (AREA)
  • Engineering & Computer Science (AREA)
  • Forests & Forestry (AREA)
  • Wood Science & Technology (AREA)
  • Chemical Kinetics & Catalysis (AREA)
  • Health & Medical Sciences (AREA)
  • Medicinal Chemistry (AREA)
  • Polymers & Plastics (AREA)
  • Organic Chemistry (AREA)
  • Materials Engineering (AREA)
  • Biochemistry (AREA)
  • Chemical And Physical Treatments For Wood And The Like (AREA)
  • Treatments For Attaching Organic Compounds To Fibrous Goods (AREA)

Abstract

La réaction d'un matériau lignocellulosique avec de l'anhydride acétique en phase vapeur améliore considérablement la stabilité dimensionnelle et la résistance aux attaques biologiques. La réaction se fait en absence de co-solvant ou de catalyseur ajouté, d'une manière simple et très rapide avec une optimisation de l'alimentation en produit à traiter et sans qu'il soit nécessaire d'effectuer une étape de distillation/rectification. Du matériau lignocellulosique partiellement ou totalement séché est traité à chaud avec de l'anhydride acétique en phase vapeur pendant une durée très courte, cette durée étant adaptée à la taille du matériau. On fait réagir le matériau et on le sèche avec ou sans circulation de gaz. Une analyse d'un échantillon volatil sur le produit obtenu permet de confirmer que la réaction s'est faite avec le rendement et le gain de poids souhaités. L'acide acétique est simplement enlevé et traité par un cétène connu pour sa réévaporation.
PCT/GB1993/001576 1992-10-15 1993-07-26 Procede pour la modification d'un materiau lignocellulosique, en phase vapeur WO1994009057A1 (fr)

Applications Claiming Priority (2)

Application Number Priority Date Filing Date Title
GB9221632A GB2271570A (en) 1992-10-15 1992-10-15 Treating lignocellusosic material with acetic anhydride
GB9221632.4 1992-10-15

Publications (1)

Publication Number Publication Date
WO1994009057A1 true WO1994009057A1 (fr) 1994-04-28

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PCT/GB1993/001576 WO1994009057A1 (fr) 1992-10-15 1993-07-26 Procede pour la modification d'un materiau lignocellulosique, en phase vapeur

Country Status (2)

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GB (1) GB2271570A (fr)
WO (1) WO1994009057A1 (fr)

Cited By (8)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
EP0650998A1 (fr) * 1993-10-28 1995-05-03 A-Cell Acetyl Cellulosics AB Acétylation de matériaux lignocellulosiques
WO1995023168A1 (fr) * 1994-02-24 1995-08-31 A-Cell Acetyl Cellulosics Ab Acetylation de matieres lignocellulosiques
EP0680810A1 (fr) * 1994-05-04 1995-11-08 Stichting Hout Research ( Shr) Procédé pour l'acétylation du bois
WO1996019526A1 (fr) * 1994-12-19 1996-06-27 A-Cell Acetyl Cellulosics Ab Procede d'acetylation de fibres lignocellulosiques
FR2814107A1 (fr) * 2000-09-21 2002-03-22 Commissariat Energie Atomique Procede de traitement chimique d'un substrat
EP2289980A1 (fr) 2009-07-30 2011-03-02 Danish Plant Fibre Technologies Holding A/S Procédé et appareil pour la modification de matériaux lignocellulosiques et produits à base de matériaux lignocellulosiques obtenus selon ledit procédé
WO2012095108A1 (fr) 2011-01-10 2012-07-19 Danish Plant Fibre Technologies Holding A/S Procédé et appareil pour la modification de matériaux lignocellulosiques et produits matériaux lignocellulosiques modifiés obtenus par le procédé
WO2014195860A1 (fr) 2013-06-03 2014-12-11 Chemconserve B.V. Fibres de bois modifiées pour la fabrication de composites

Families Citing this family (1)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US8906466B2 (en) 2009-06-25 2014-12-09 Eastman Chemical Company Esterified lignocellulosic materials and methods for making them

Citations (3)

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SU451707A1 (ru) * 1972-09-18 1974-11-30 Всесоюзное научно-производственное объединение целлюлозно-бумажной промышленности Способ получени ацетатов целлюлозы
JPS60242003A (ja) * 1985-03-09 1985-12-02 大建工業株式会社 改質木材
EP0213252A1 (fr) * 1985-08-28 1987-03-11 A-Cell Acetyl Cellulosics AB Procédé pour améliorer la stabilité dimensionnelle et la résistance biologique de matière lignocellulosique

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GB345800A (en) * 1930-03-11 1931-04-02 Eastman Kodak Co Process of making cellulose acetate
US2780511A (en) * 1953-05-14 1957-02-05 Toho Rayon Kk Methiod of making cellulose acetate teixtile fibers by acetylization of relgenerated cellulose fibers
GB964197A (en) * 1962-07-10 1964-07-15 Rayonier Inc Improvements in acetylation of cellulose

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Publication number Priority date Publication date Assignee Title
SU451707A1 (ru) * 1972-09-18 1974-11-30 Всесоюзное научно-производственное объединение целлюлозно-бумажной промышленности Способ получени ацетатов целлюлозы
JPS60242003A (ja) * 1985-03-09 1985-12-02 大建工業株式会社 改質木材
EP0213252A1 (fr) * 1985-08-28 1987-03-11 A-Cell Acetyl Cellulosics AB Procédé pour améliorer la stabilité dimensionnelle et la résistance biologique de matière lignocellulosique

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* Cited by examiner, † Cited by third party
Title
DATABASE PAPERCHEM THE INSTITUTE OF PAPER SCIENCE AND TECHNOLOGY, ATLANTA, GA, US; FAHMY, Y. A. ET AL: "Acetylation in Particle Board Making" *
DATABASE PAPERCHEM THE INSTITUTE OF PAPER SCIENCE AND TECHNOLOGY, ATLANTA, GA, US; KORCHEMKIN, F. I. ET AL: "METHOD OF EXTENSIVE ACETYLATION OF BOARD" *
DATABASE PAPERCHEM THE INSTITUTE OF PAPER SCIENCE AND TECHNOLOGY, ATLANTA, GA, US; SHVALBE, K. P. ET AL: "MODIFICATION OF WOOD BY ACETYLATION" *
DATABASE WPI Section Ch Week 7534, Derwent World Patents Index; Class A11, AN 75-56732W *
DATABASE WPI Section Ch Week 8603, Derwent World Patents Index; Class A82, AN 86-018161 *
EGYPTIAN J. CHEM. 20, NO. 4: 397-403 (1977). [ENGL.;ARABIC SUM.] *
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Cited By (12)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
EP0650998A1 (fr) * 1993-10-28 1995-05-03 A-Cell Acetyl Cellulosics AB Acétylation de matériaux lignocellulosiques
WO1995023168A1 (fr) * 1994-02-24 1995-08-31 A-Cell Acetyl Cellulosics Ab Acetylation de matieres lignocellulosiques
US5777101A (en) * 1994-02-24 1998-07-07 A-Cell Acetyl Cellulosics Ab Acetylation of lignocellulosic materials
EP0680810A1 (fr) * 1994-05-04 1995-11-08 Stichting Hout Research ( Shr) Procédé pour l'acétylation du bois
WO1996019526A1 (fr) * 1994-12-19 1996-06-27 A-Cell Acetyl Cellulosics Ab Procede d'acetylation de fibres lignocellulosiques
AU693631B2 (en) * 1994-12-19 1998-07-02 A-Cell Acetyl Cellulosics Ab Acetylation of lignocellulosic fibres
US5821359A (en) * 1994-12-19 1998-10-13 A-Cell Acetyl Cellulosics Ab Acetylation of lignocellulosic fibres
FR2814107A1 (fr) * 2000-09-21 2002-03-22 Commissariat Energie Atomique Procede de traitement chimique d'un substrat
WO2002024420A1 (fr) * 2000-09-21 2002-03-28 Atelier Regional De Conservation Arc-Nucleart Procede de traitement chimique d'un substrat.
EP2289980A1 (fr) 2009-07-30 2011-03-02 Danish Plant Fibre Technologies Holding A/S Procédé et appareil pour la modification de matériaux lignocellulosiques et produits à base de matériaux lignocellulosiques obtenus selon ledit procédé
WO2012095108A1 (fr) 2011-01-10 2012-07-19 Danish Plant Fibre Technologies Holding A/S Procédé et appareil pour la modification de matériaux lignocellulosiques et produits matériaux lignocellulosiques modifiés obtenus par le procédé
WO2014195860A1 (fr) 2013-06-03 2014-12-11 Chemconserve B.V. Fibres de bois modifiées pour la fabrication de composites

Also Published As

Publication number Publication date
GB9221632D0 (en) 1992-11-25
GB2271570A (en) 1994-04-20

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