EP0699510B1 - Method for reducing the formaldehyde emission from lignocellulosic products - Google Patents
Method for reducing the formaldehyde emission from lignocellulosic products Download PDFInfo
- Publication number
- EP0699510B1 EP0699510B1 EP95112789A EP95112789A EP0699510B1 EP 0699510 B1 EP0699510 B1 EP 0699510B1 EP 95112789 A EP95112789 A EP 95112789A EP 95112789 A EP95112789 A EP 95112789A EP 0699510 B1 EP0699510 B1 EP 0699510B1
- Authority
- EP
- European Patent Office
- Prior art keywords
- formaldehyde
- tannin
- urea
- lignocellulosic
- chipboard
- 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.)
- Expired - Lifetime
Links
Classifications
-
- B—PERFORMING OPERATIONS; TRANSPORTING
- B27—WORKING OR PRESERVING WOOD OR SIMILAR MATERIAL; NAILING OR STAPLING MACHINES IN GENERAL
- B27N—MANUFACTURE BY DRY PROCESSES OF ARTICLES, WITH OR WITHOUT ORGANIC BINDING AGENTS, MADE FROM PARTICLES OR FIBRES CONSISTING OF WOOD OR OTHER LIGNOCELLULOSIC OR LIKE ORGANIC MATERIAL
- B27N1/00—Pretreatment of moulding material
- B27N1/003—Pretreatment of moulding material for reducing formaldehyde gas emission
Definitions
- the invention relates to a method for reducing the Formaldehyde release from aminoplast-bound pressed lignocellulose products, in particular chipboard and fiberboard, by gluing wood fibers and wood chips with condensation products from urea and / or melamine and / or phenol and formaldehyde, optionally in a mixture with another Aldehyde.
- chipboard for furniture construction and that Construction becomes wood shavings or other lignocellulose-containing Particles with a urea-formaldehyde resin in quantities of usually from 8 to 10% by weight, based on the dry Chip material, glued, scattered to chip mats and under heat and Pressure pressed.
- the still hot chipboard is made after the Presses are usually stacked.
- binders can be used such as alkaline curing phenol formaldehyde resins, polymers based on diisocyanates (PMDI) etc. can be used. So far, these binders have only been comparatively small Importance because they are either expensive or have other disadvantages have.
- PMDI diisocyanates
- the urea-formaldehyde resins or other amino resins contain as a binder, give after production formaldehyde over a relatively long period of time.
- the release of formaldehyde this type of plate depends on various factors how molar ratio of urea to formaldehyde in the used resin, pressing time, binder expenditure, age of the plates etc.
- the formaldehyde released can reach values that the Well-being of people in rooms where with urea-formaldehyde resin bound chipboard are built in, strong affect.
- Chipboard For the determination of formaldehyde release from Chipboard offers several methods, including these the perforator method (DIN EN 120), the gas analysis method (DIN 52368) and the WKI bottle method (Roffael 1975 / Pr EN 717).
- the emission of formaldehyde from chipboard can also be with the help of test rooms, in which the temperature, the number of air changes and the room load are fixed. After the Hazardous Substances Ordinance of October 1993 or the Chemicals prohibition ordinance are not allowed in the wood materials Placed on the market when their emission of formaldehyde in a defined climatic chamber is more than 0.1 ppm.
- urea formaldehyde resins with a low content of condensed formaldehyde use or the molar ratio formaldehyde: urea belittling.
- the use of these resins does decrease the subsequent release of formaldehyde is considerable, but can on the physical-technical properties of the manufactured Chipboards have a negative impact.
- the urea-formaldehyde resin has also been proposed Molecular compounds of various types to mix the To reduce formaldehyde emissions (Kubitzky, INDUSTRIE-ANZEIGER No. 53, Edition Plastics - Processing and Application, Göppingen 1972).
- EP-A 0012 169 multi-layer, predominantly aminoplast-bound Particle or fiberboard described in an interior, preferably in the middle layer, as Binder not belonging to the aminoplast group Glue, e.g. Diisocyanate, and which are characterized are that only such binders for this interior can be used, the curing of which by the presence of additional formaldehyde-reactive substances are not affected is, the binder these additional substances in the form of ammonia, ammonium carbonate, ureas, thioureas, Melamine or dicyandiamide are mixed in with the after the pressing of the plate still existing or released Formaldehyde under the influence of moisture and / or heat directly, possibly also indirectly via fission products, setting it react.
- Binder not belonging to the aminoplast group Glue e.g. Diisocyanate
- EP-PS 0 006 486 describes a method for reduction the release of formaldehyde from aminoplast-bound chipboard or Fiberboard known in which on the surface of the plates in hot state immediately or at short intervals their removal from the heating press urea or other ammonia releasing substances applied in the form of an aqueous solution will.
- a process which is similar in principle, in which the plates already cooled to a conditioning temperature an ammonium salt solution is applied from the EP-PS 0 027 583 known.
- the present invention is in relation to the cited state based on the task, plates with extreme produce lower formaldehyde release, their formaldehyde release hardly differs from that of natural wood differs.
- the release of formaldehyde can be reduced to a minimum by giving the chips before or during or after gluing with aminoplast resins, for example with a molar ratio F: NH 2 of about 0.6: 1 or 0.5: 1 , condensed tannin in amounts based on the weight of the wood chips from about 0.1% to a maximum of 5%, preferably 1% to 0.1%, and the plates are treated in a manner known per se with formaldehyde-reactive (basic) agents are, for example in the manner known from EP-PS 0 006 486 or EP-PS 0 027 583.
- Wood chips are coated with a urea-formaldehyde resin before gluing (e.g. 8% solids based on the weight of the wood chips) the formaldehyde-urea molar ratio F: U of 1: 1 with tannin mixed in amounts of approximately 0.5% by weight, based on the Weight of the wood chips.
- a urea-formaldehyde resin e.g. 8% solids based on the weight of the wood chips
- F formaldehyde-urea molar ratio
- the tannin can added to the chips in powder or liquid form will. Then the glued wood chips become chip mats manufactured and this in the usual way to chipboard hot pressed. After pressing, the plates are still hot Condition in the manner already known with treated with basic, i.e. formaldehyde-reactive substances, e.g. With sprayed with an aqueous urea solution.
- the chipboard produced in this way are in the table below with "Type 1" designated.
- chipboard with urea-formaldehyde resin produced without the addition of tannins and then with Sprayed formaldehyde-reactive substances when hot (type 2). Furthermore, chipboard with urea-formaldehyde resins and the chips were made with urea-formaldehyde resin before gluing with tannins in quantities of 0.5% (parts by weight based on the weight of the chips) mixed. The chipboard were not sprayed after production (type 3). Furthermore, chipboard with urea-formaldehyde resin as Binder made in quantities of 10% (parts by weight based on the weight of the wood chips). The wood chips were neither condensed tannins were added, nor were the particle boards treated with formaldehyde-reactive substances after production (Type 4).
Landscapes
- Life Sciences & Earth Sciences (AREA)
- Engineering & Computer Science (AREA)
- Manufacturing & Machinery (AREA)
- Wood Science & Technology (AREA)
- Forests & Forestry (AREA)
- Dry Formation Of Fiberboard And The Like (AREA)
- Compounds Of Unknown Constitution (AREA)
- Chemical And Physical Treatments For Wood And The Like (AREA)
- Paper (AREA)
- Polysaccharides And Polysaccharide Derivatives (AREA)
Abstract
Description
Die Erfindung betrifft ein Verfahren zur Verminderung der Formaldehydabgabe von aminoplastgebundenen gepreßten Lignocellulose-Erzeugnissen, insbesondere Holzspan- und Faserplatten, die durch Verleimung von Holzfasern und Holzspänen mit Kondensationsprodukten aus Harnstoff und/oder Melamin und/oder Phenol sowie Formaldehyd, gegebenfalls im Gemisch mit einem anderen Aldehyd, hergestellt werden.The invention relates to a method for reducing the Formaldehyde release from aminoplast-bound pressed lignocellulose products, in particular chipboard and fiberboard, by gluing wood fibers and wood chips with condensation products from urea and / or melamine and / or phenol and formaldehyde, optionally in a mixture with another Aldehyde.
Für die Herstellung von Spanplatten für den Möbelbau und das Bauwesen werden Holzspäne oder andere lignocellulosehaltige Partikel mit einem Harnstoff-Formaldehydharz in Mengen von üblicherweise von 8 bis 10 Gew.%, bezogen auf das trockene Spangut, beleimt, zu Spanmatten gestreut und unter Hitze und Druck gepreßt. Die noch heißen Spanplatten werden nach dem Pressen in der Regel gestapelt.For the production of chipboard for furniture construction and that Construction becomes wood shavings or other lignocellulose-containing Particles with a urea-formaldehyde resin in quantities of usually from 8 to 10% by weight, based on the dry Chip material, glued, scattered to chip mats and under heat and Pressure pressed. The still hot chipboard is made after the Presses are usually stacked.
An Stelle eines Harnstoff-Formaldehydharzes können andere Bindemittel wie alkalisch härtende Phenolformaldehydharze, Polymere auf Basis von Diisocyanaten (PMDI) usw. verwendet werden. Diese Bindemittel haben bislang nur eine vergleichsweise geringe Bedeutung, da sie entweder teuer sind oder andere Nachteile besitzen.Instead of a urea-formaldehyde resin, other binders can be used such as alkaline curing phenol formaldehyde resins, polymers based on diisocyanates (PMDI) etc. can be used. So far, these binders have only been comparatively small Importance because they are either expensive or have other disadvantages have.
Spanplatten, die Harnstoff-Formaldehydharze oder andere Aminoharze als Bindemittel enthalten, geben nach der Herstellung über relativ lange Zeiträume hinweg Formaldehyd ab. Die Formaldehydabgabe dieses Plattentyps hängt von verschiedenen Faktoren ab, wie Molverhältnis von Harnstoff zu Formaldehyd in dem verwendeten Harz, Preßzeit, Bindemittelaufwand, Alter der Platten usw. Das abgegebene Formaldehyd kann Werte erreichen, die das Wohlbefinden von Menschen in Räumen, in denen mit Harnstoff-Formaldehydharz gebundene Spanplatten eingebaut sind, stark beeinträchtigen. Für die Bestimmung der Formaldehydabgabe von Holzspanplatten bieten sich mehrere Verfahren an, hierzu gehören das Perforatorverfahren (DIN EN 120), die Gasanalysemethode (DIN 52368) und die WKI-Flaschenmethode (Roffael 1975/ Pr EN 717). Die Emission von Formaldehyd aus Holzspanplatten läßt sich auch mit Hilfe von Prüfräumen, bei denen die Temperatur, die Luftwechselzahl und die Raumbeladung fixiert sind, ermitteln. Nach der Gefahrstoffverordnung vom Oktober 1993 bzw. der Chemikalienverbotverordnung dürfen Holzwerkstoffe nicht in den Verkehr gebracht werden, wenn ihre Emission an Formaldehyd in einer definierten Klimakammer mehr als 0,1 ppm beträgt.Particle boards, the urea-formaldehyde resins or other amino resins contain as a binder, give after production formaldehyde over a relatively long period of time. The release of formaldehyde this type of plate depends on various factors how molar ratio of urea to formaldehyde in the used resin, pressing time, binder expenditure, age of the plates etc. The formaldehyde released can reach values that the Well-being of people in rooms where with urea-formaldehyde resin bound chipboard are built in, strong affect. For the determination of formaldehyde release from Chipboard offers several methods, including these the perforator method (DIN EN 120), the gas analysis method (DIN 52368) and the WKI bottle method (Roffael 1975 / Pr EN 717). The emission of formaldehyde from chipboard can also be with the help of test rooms, in which the temperature, the number of air changes and the room load are fixed. After the Hazardous Substances Ordinance of October 1993 or the Chemicals prohibition ordinance are not allowed in the wood materials Placed on the market when their emission of formaldehyde in a defined climatic chamber is more than 0.1 ppm.
Um die nachträgliche Formaldehydabgabe von Spanplatten zu verringern, ist bereits vorgeschlagen worden, Harnstoff-Formaldehydharze mit niedrigem Gehalt an einkondensiertem Formaldehyd einzusetzen bzw. das Molverhältnis Formaldehyd : Harnstoff herabzusetzen. Die Verwendung dieser Harze verringert zwar die nachträgliche Formaldehydabgabe erheblich, kann sich aber auf die physikalisch-technischen Eigenschaften der hergestellten Holzspanplatten negativ auswirken.To reduce the subsequent release of formaldehyde from chipboard, has already been proposed urea formaldehyde resins with a low content of condensed formaldehyde use or the molar ratio formaldehyde: urea belittling. The use of these resins does decrease the subsequent release of formaldehyde is considerable, but can on the physical-technical properties of the manufactured Chipboards have a negative impact.
Weiterhin ist bekannt, daß durch Beimengung von Harnstoff und/oder Ammoniak zum Harnstoff-Formaldehydharz die Formaldehydabgabe verringert werden kann, da diese Stoffe das Formaldehyd chemisch abzubinden vermögen. Die Zugabe von derartigen Stoffen zum Harz ist nur begrenzt möglich, da mit zunehmendem Gehalt an derartigen Stoffen die Abbindegeschwindigkeit des Harzes verlangsamt wird und die physikalisch-technologischen Eigenschaften bei konstanter Preßzeit verschlechtert werden können.It is also known that by admixing urea and / or ammonia to the urea-formaldehyde resin the formaldehyde release can be reduced because these substances the formaldehyde can chemically set. The addition of such substances Resin is only possible to a limited extent since the content of such substances, the setting speed of the resin is slowed down and the physical-technological properties can deteriorate with constant pressing time.
Auch ist bereits vorgeschlagen worden, den Holzspänen nach dem Beleimen feinteilige Stoffe beizumengen, die mit Formaldehyd chemisch reagieren (DE-OS 1 653 167). Man verwendet solche Stoffe, die mit dem Formaldehyd langsamer reagieren, als es der Kondensationsgeschwindigkeit des Harzes entspricht. Solche Stoffe sind z.B. Melamin, Harnstoff, Polyacrylsäureamid, Guanidin, Hydroxylamin, Ethylendiamin, Phenol, Resorcin, Diphenylmethandiisocyanat (MDI).It has also been suggested that the wood chips after the Glue to add finely divided substances with formaldehyde react chemically (DE-OS 1 653 167). One uses such Substances that react with the formaldehyde more slowly than it does corresponds to the rate of condensation of the resin. Such Fabrics are e.g. Melamine, urea, polyacrylic acid amide, Guanidine, hydroxylamine, ethylenediamine, phenol, resorcinol, Diphenylmethane diisocyanate (MDI).
Ferner ist vorgeschlagen worden, dem Harnstoff-Formaldehydharz Molekülverbindungen verschiedener Art beizumengen, die die Formaldehydabgabe verringern sollen (Kubitzky, INDUSTRIE-ANZEIGER Nr. 53, Ausgabe Kunststoffe - Verarbeitung und Anwendung, Göppingen 1972).The urea-formaldehyde resin has also been proposed Molecular compounds of various types to mix the To reduce formaldehyde emissions (Kubitzky, INDUSTRIE-ANZEIGER No. 53, Edition Plastics - Processing and Application, Göppingen 1972).
Es ist ferner vorgeschlagen worden (DE-OS 2 317 884), bei der Herstellung von Holzspanplatten dem Harnstoff-Formaldehydharz Gerbstoffe oder Gerbstoffderivate beizumengen, um die Formaldehydabgabe der hergestellten Holzwerkstoffe bzw. Spanplatten herabzusetzen. In dieser Offenlegungsschrift werden jedoch hierfür keine quantitativen Beispiele genannt. In einem Artikel von Cammeron und Pizzi (ACS-Symposium Series 316, p. 198-200, 1986) wird festgestellt, daß die Zugabe von Tanninen bei der Verleimung von Holzspänen mit Harnstoff-Formaldehydharzen die Formaldehydabgabe nur vorübergehend verringert, so daß tanninhaltige und nicht tanninhaltige Holz-spanplatten nach einer kurzen Zeit von etwa einer Woche annähernd die gleiche Formaldehydabgabe aufwiesen.It has also been proposed (DE-OS 2 317 884), in which Manufacture of chipboard made of urea-formaldehyde resin Add tannins or tannin derivatives to the formaldehyde release to reduce the wood materials or chipboard produced. This disclosure, however, does this no quantitative examples given. In an article by Cammeron and Pizzi (ACS Symposium Series 316, p. 198-200, 1986) it is found that the addition of tannins during the gluing the release of formaldehyde from wood chips with urea-formaldehyde resins only temporarily reduced, so that tannic and Wood chipboard not containing tannins after a short period of had approximately the same formaldehyde release for about a week.
Ferner ist bekannt, daß die nachträgliche Abgabe von Formaldehyd dadurch verringert werden kann, daß man die Holzspanplatten mit einem Anstrichsystem auf Basis wäßriger Kunststoffdispersionsfarbe bestimmter Zusammensetzung allseitig streicht. Dieses formaldehydbindende Anstrichmittel für Holzspanplatten enthält Ammoniak, Milchsäurekasein und Hydrazinhydrat in bestimmter Zusammensetzung (DE-PS 1 188 750).It is also known that the subsequent release of formaldehyde can be reduced by having the chipboard with a paint system based on aqueous plastic emulsion paint certain composition strokes on all sides. This contains formaldehyde-binding paint for particle board Ammonia, lactic acid casein and hydrazine hydrate in certain Composition (DE-PS 1 188 750).
In der EP-A 0012 169 werden mehrschichtige, vorwiegend aminoplastgebundene Span- oder Faserplatten beschrieben, die in einem Innenbereich, vorzugsweise in der Mittelschicht, als Bindemittel einen nicht zur Gruppe der Aminoplaste gehörenden Kleber, z.B. Diisocyanat, aufweisen und die dadurch gekennzeichnet sind, daß für diesen Innenbereich nur solche Bindemittel verwendet werden, deren Aushärtung durch die Anwesenheit von zusätzlichen formaldehydreaktiven Stoffen nicht beeinträchtigt wird, wobei dem Bindemittel diese zusätzlichen Stoffe in Form von Ammoniak, Ammoniumcarbonat, Harnstoffen, Thioharnstoffen, Melamin oder Dicyandiamid beigemischt sind, die mit dem nach dem Pressen der Platte noch vorhandenen oder freiwerdenden Formaldehyd unter Feuchte- und/oder Wärmeeinwirkung direkt, gegebenenfalls auch indirekt über Spaltprodukte, ihn abbindend reagieren.In EP-A 0012 169 multi-layer, predominantly aminoplast-bound Particle or fiberboard described in an interior, preferably in the middle layer, as Binder not belonging to the aminoplast group Glue, e.g. Diisocyanate, and which are characterized are that only such binders for this interior can be used, the curing of which by the presence of additional formaldehyde-reactive substances are not affected is, the binder these additional substances in the form of ammonia, ammonium carbonate, ureas, thioureas, Melamine or dicyandiamide are mixed in with the after the pressing of the plate still existing or released Formaldehyde under the influence of moisture and / or heat directly, possibly also indirectly via fission products, setting it react.
Aus der EP-PS 0 006 486 ist ein Verfahren zur Verminderung der Formaldehydabgabe von aminoplastgebundenen Span- oder Faserplatten bekannt, bei dem auf die Oberfläche der Platten im heißen Zustand unmittelbar oder in kurzem Zeitabstand nach deren Entnahme aus der Heizpresse Harnstoffe oder andere Ammoniak abspaltende Stoffe in Form einer wäßrigen Lösung aufgebracht werden. Ein im Prinzip ähnliches Verfahren, bei dem auf die bereits auf eine Konditionierungstemperatur abgekühlten Platten eine Ammoniumsalzlösung aufgebracht wird, ist aus der EP-PS 0 027 583 bekannt.EP-PS 0 006 486 describes a method for reduction the release of formaldehyde from aminoplast-bound chipboard or Fiberboard known in which on the surface of the plates in hot state immediately or at short intervals their removal from the heating press urea or other ammonia releasing substances applied in the form of an aqueous solution will. A process which is similar in principle, in which the plates already cooled to a conditioning temperature an ammonium salt solution is applied from the EP-PS 0 027 583 known.
Der vorliegenden Erfindung liegt gegenüber dem zitierten Stand der Kenntnisse die Aufgabe zugrunde, Platten mit extrem niedriger Formaldehydabgabe herzustellen, deren Formaldehydabgabe sich kaum von derjenigen des naturbelassenen Holzes unterscheidet.The present invention is in relation to the cited state based on the task, plates with extreme produce lower formaldehyde release, their formaldehyde release hardly differs from that of natural wood differs.
Diese Aufgabe wird durch das im Anspruch 1 gekennzeichnete Verfahren gelöst. This object is characterized by that in claim 1 Procedure solved.
Es wurde überraschend gefunden, daß die Formaldehydabgabe dadurch auf ein Minimum reduziert werden kann, daß den Spänen vor oder während oder nach dem Beleimen mit Aminoplastharzen, z.B. mit einem Molverhältnis F:NH2 von etwa 0,6:1 oder 0,5:1, kondensiertes Tannin in auf das Gewicht der Holzspäne bezogenen Mengen von ungefähr 0,1% bis maximal 5%, vorzugsweise 1% bis 0,1% beigegeben wird und die Platten nach dem Pressen in an sich bekannter Weise mit formaldehydreaktiven (basischen) Mitteln behandelt werden, z.B. in der aus der EP-PS 0 006 486 oder der EP-PS 0 027 583 bekannten Weise.It has surprisingly been found that the release of formaldehyde can be reduced to a minimum by giving the chips before or during or after gluing with aminoplast resins, for example with a molar ratio F: NH 2 of about 0.6: 1 or 0.5: 1 , condensed tannin in amounts based on the weight of the wood chips from about 0.1% to a maximum of 5%, preferably 1% to 0.1%, and the plates are treated in a manner known per se with formaldehyde-reactive (basic) agents are, for example in the manner known from EP-PS 0 006 486 or EP-PS 0 027 583.
Das in der EP-PS 0 006 486 beschriebene Verfahren allein reicht dafür nicht aus, da das erreichte Formaldehydabgabeniveau wesentlich höher ist als das nach dem erfindungsgemäßen Verfahren. Auch das gemäß der DE-OS 2 317 884 beschriebene Verfahren eignet sich hierfür nicht, da ohne nachträgliche Besprühung der Platten nach dem Pressen das kondensierte Tannin keine Wirkung auf die Formaldehydabgabe der Platten entfaltet.The method described in EP-PS 0 006 486 alone is sufficient not for this, since the formaldehyde release level reached is significantly higher than that according to the method according to the invention. The method described in DE-OS 2 317 884 is also suitable not for this, because without subsequent spraying of the plates after pressing the condensed tannin has no effect on the The formaldehyde release of the plates unfolds.
An dem folgenden Beispiel wird die Erfindung näher erläutert.The invention is explained in more detail in the following example.
Holzspäne werden vor dem Beleimen mit einem Harnstoff-Formaldehydharz (z.B. 8% Feststoff bezogen auf das Gewicht der Holzspäne) des Formaldehyd-Harnstoff-Molverhältnisses F:U von 1:1 mit Tannin in Mengen von ungefähr 0,5 Gew.% gemischt, bezogen auf das Gewicht der Holzspäne. Man unterscheidet zwischen hydrolysierbaren Tanninen und kondensierten Tanninen, von denen letztere eine wesentlich höhere Reaktionsfähigkeit gegenüber dem Formaldehyd haben (Holz-Zentralblatt 1994, Nr. 6, S. 90-93) und deshalb bei dem hier beschriebenen Verfahren bevorzugt werden. Das kondensierte Tannin wird vorzugsweise aus Quebrachoholz gewonnen, in an sich bekannter Weise durch Auskochen des Holzes, worauf der gewonnene Extrakt getrocknet und pulverisiert werden kann. Das Tannin kann den Spänen in Pulverform oder auch in flüssiger Form zugegeben werden. Anschließend werden aus den beleimten Holzspänen Spanmatten hergestellt und diese in üblicher Weise zu Spanplatten heiß gepreßt. Nach dem Pressen werden die Platten in noch heißem Zustand in der schon erwähnten, an sich bekannten Weise mit basischen, also formaldehydreaktiven Stoffen behandelt, z.B. mit einer wäßrigen Harnstofflösung besprüht. Die so erzeugten Spanplatten sind in der weiter unten folgenden Tabelle mit "Typ 1" bezeichnet.Wood chips are coated with a urea-formaldehyde resin before gluing (e.g. 8% solids based on the weight of the wood chips) the formaldehyde-urea molar ratio F: U of 1: 1 with tannin mixed in amounts of approximately 0.5% by weight, based on the Weight of the wood chips. A distinction is made between hydrolyzable Tannins and condensed tannins, the latter one much higher reactivity to formaldehyde have (Holz-Zentralblatt 1994, No. 6, pp. 90-93) and therefore at the method described here are preferred. That condensed Tannin is preferably obtained from quebracho wood, in itself known way by boiling the wood, whereupon the obtained Extract can be dried and pulverized. The tannin can added to the chips in powder or liquid form will. Then the glued wood chips become chip mats manufactured and this in the usual way to chipboard hot pressed. After pressing, the plates are still hot Condition in the manner already known with treated with basic, i.e. formaldehyde-reactive substances, e.g. With sprayed with an aqueous urea solution. The chipboard produced in this way are in the table below with "Type 1" designated.
Zum Vergleich wurden Spanplatten mit Harnstoff-Formaldehydharz ohne Zugabe von Gerbstoffen hergestellt und anschließend mit formaldehydreaktiven Stoffen in heißem Zustand besprüht (Typ 2). Ferner wurden Spanplatten mit Harnstoff-Formaldehydharzen hergestellt und die Späne wurden vor dem Beleimen mit Harnstoff-Formaldehydharz mit Tanninen in Mengen von 0,5% (Gewichtsanteile bezogen auf das Gewicht der Späne) gemischt. Die Spanplatten wurden jedoch nach der Herstellung nicht bespruht (Typ 3). Weiterhin wurden Spanplatten mit Harnstoff-Formaldehydharz als Bindemittel hergestellt in Mengen von 10% (Gewichtsanteile bezogen auf das Gewicht der Holzspäne). Den Holzspänen wurden weder kondensierte Tannine zugegeben, noch wurden die Spanplatten nach der Herstellung mit formaldehydreaktiven Stoffen nachbehandelt (Typ 4).For comparison, chipboard with urea-formaldehyde resin produced without the addition of tannins and then with Sprayed formaldehyde-reactive substances when hot (type 2). Furthermore, chipboard with urea-formaldehyde resins and the chips were made with urea-formaldehyde resin before gluing with tannins in quantities of 0.5% (parts by weight based on the weight of the chips) mixed. The chipboard were not sprayed after production (type 3). Furthermore, chipboard with urea-formaldehyde resin as Binder made in quantities of 10% (parts by weight based on the weight of the wood chips). The wood chips were neither condensed tannins were added, nor were the particle boards treated with formaldehyde-reactive substances after production (Type 4).
Aus dem tabellierten Angaben wird ersichtlich, daß die Zugabe
von Tanninen zu den Spänen vor dem Beleimen mit dem Harnstoff-Formaldehydharz
und anschließendem Pressen keine nennenswerte
Wirkung auf die Formaldehydabgabe der hergestellten Spanplatten
hat, solange die hergestellten Spanplatten nicht nachbehandelt
werden (vgl. Typ 3 und 4). Demgegenüber ist zwar die Wirkung
der Besprühung auf die Formaldehydabgabe der Spanplatten, die
keine Tannine enthalten, deutlich festzustellen (Typ 2). Diese
Wirkung ist jedoch weitaus geringer, als wenn die Spanplatten
Tannine enthalten (Typ 1). Insofern unterscheidet sich das hier
beschriebene Verfahren also grundlegend von allen bekannten
Verfahren, da die Wirkung der kondensierten Tannine als
formaldehydreduzierendes Mittel erst nach der Besprühung zum
Tragen kommt.
Claims (10)
- Method of reducing the emission of formaldehyde from aminoplastic-bonded, pressed lignocellulosic products, particularly woodchip or fibre boards, characterised in that before, during or after the gluing with aminoplastic resins condensed tannin is added to the lignocellulosic materials and after the pressing process a substance which reacts with formaldehyde is applied to the manufactured lignocellulosic product.
- Method as claimed in Claim 1, characterised in that the tannin is added to the lignocellulosic materials in powder form.
- Method as claimed in Claim 1, characterised in that the tannin is added to the lignocellulosic materials in liquid form.
- Method as claimed in Claim 1, 2 or 3, characterised in that the tannin is added in amounts of at least 0.1% with respect to the weight of the lignocellulosic materials.
- Method as claimed in Claim 1, 2 or 3, characterised in that the tannin is added to the lignocellulosic materials in amounts of at most 5% with respect to the weight of the lignocellulosic materials.
- Method as claimed in Claim 1, characterised in that the lignocellulosic board is sprayed with the substance which reacts with formaldehyde.
- Method as claimed in one of the preceding claims, characterised in that urea or another substance which liberates ammonia is applied as the substance which reacts with formaldehyde.
- Method as claimed in one of Claims 1 to 7, characterised in that the tannin is introduced only into the surface layers of multilayer chip boards.
- Method as claimed in one of Claims 1 to 7, characterised in that the tannin is introduced only into the middle layer of multilayer chip boards.
- Method as claimed in one of Claims 1 to 7, characterised in that the tannin is introduced both into the middle layer and also into the surface layers of multilayer chip boards.
Applications Claiming Priority (2)
Application Number | Priority Date | Filing Date | Title |
---|---|---|---|
DE4431316A DE4431316C1 (en) | 1994-09-02 | 1994-09-02 | Process for reducing the release of formaldehyde from chipboard or fiberboard |
DE4431316 | 1994-09-02 |
Publications (3)
Publication Number | Publication Date |
---|---|
EP0699510A2 EP0699510A2 (en) | 1996-03-06 |
EP0699510A3 EP0699510A3 (en) | 1996-07-10 |
EP0699510B1 true EP0699510B1 (en) | 1998-05-20 |
Family
ID=6527279
Family Applications (1)
Application Number | Title | Priority Date | Filing Date |
---|---|---|---|
EP95112789A Expired - Lifetime EP0699510B1 (en) | 1994-09-02 | 1995-08-14 | Method for reducing the formaldehyde emission from lignocellulosic products |
Country Status (3)
Country | Link |
---|---|
EP (1) | EP0699510B1 (en) |
AT (1) | ATE166278T1 (en) |
DE (2) | DE4431316C1 (en) |
Cited By (3)
Publication number | Priority date | Publication date | Assignee | Title |
---|---|---|---|---|
DE102005019627B3 (en) * | 2005-04-26 | 2006-10-26 | Fraunhofer-Gesellschaft zur Förderung der angewandten Forschung e.V. | Medium density fiberboards, of digested ligno cellulose refined into fibers, contains a bonding agent giving a low emission of volatile organic compounds |
US8623501B2 (en) | 2010-03-04 | 2014-01-07 | Basf Se | Lignocellulose materials having good mechanical properties |
US8920923B2 (en) | 2010-03-04 | 2014-12-30 | Basf Se | Lignocellulose materials having good mechanical properties |
Families Citing this family (7)
Publication number | Priority date | Publication date | Assignee | Title |
---|---|---|---|---|
DE59700001D1 (en) * | 1996-02-09 | 1998-06-25 | Schlingmann Gmbh & Co | Process for the production of low-formaldehyde tannin-bound chipboard and fiberboard |
DE19751326C2 (en) * | 1997-11-19 | 2001-01-04 | Pfleiderer Unternehmensverwalt | Process for the production of wood materials using used, residual and waste wood materials |
DE69730221T2 (en) * | 1997-12-15 | 2005-08-18 | Silva S.R.L., Pamparato | Thermosetting adhesives of condensed tannins and use in the wood industry |
ATE321636T1 (en) * | 2001-06-12 | 2006-04-15 | Edmone Roffael | METHOD FOR PRODUCING MOISTURE-RESISTANT CHIPBOARD AND MEDIUM-DENSITY FIBERBOARD (MDF) |
DE20316621U1 (en) * | 2003-10-28 | 2004-02-12 | Fritz Egger Gmbh & Co | Low-emission OSB board |
WO2009101100A2 (en) | 2008-02-11 | 2009-08-20 | Basf Se | Formaldehyde-free binders for producing wood products |
EP2172333A1 (en) * | 2008-09-19 | 2010-04-07 | Basf Se | Multi-layered form bodies with low formaldehyde emission containing lignocellulose |
Family Cites Families (9)
Publication number | Priority date | Publication date | Assignee | Title |
---|---|---|---|---|
DE1653167A1 (en) * | 1967-11-24 | 1971-09-16 | Basf Ag | Process for the production of chipboard with reduced subsequent release of formaldehyde |
DE2317884A1 (en) * | 1973-04-10 | 1974-10-24 | E Schnitzler Gmbh & Co Dr | Wood board mfr using formaldehyde - releasing glues - FORMALDEHYDE ESCAPE BEING PREVENTED BY CHEMICALLY BONDING IN BOARD COMPSN. |
US4075394A (en) * | 1976-04-08 | 1978-02-21 | The Dow Chemical Company | Process of inhibiting tannin migration in tannin-containing wood substrates |
DE2829021C2 (en) * | 1978-07-01 | 1980-08-28 | Fraunhofer-Gesellschaft Zur Foerderung Der Angewandten Forschung E.V., 8000 Muenchen | Process for reducing the formaldehyde release from chipboard |
DE2851589C3 (en) * | 1978-11-29 | 1983-06-16 | Fraunhofer-Gesellschaft zur Förderung der angewandten Forschung e.V., 8000 München | Multi-layer chipboard or fiberboard that contains an aminoplast as a binding agent in a sub-area or sub-areas |
FI70686C (en) * | 1979-10-11 | 1986-10-06 | Swedspan Ab | SAINT ATT MINSKA EMISSIONEN AV FORMALDEHYD FRAON KARBAMIDHARTSBUNDNA SPAONSKIVOR |
DE3438735A1 (en) * | 1984-10-23 | 1986-06-26 | Desowag-Bayer Holzschutz GmbH, 4000 Düsseldorf | Process for producing chipboards or fibreboards |
DE4022348A1 (en) * | 1990-07-13 | 1992-01-16 | Fraunhofer Ges Forschung | Wood prods. mfr. esp. chipboard, with improved strength - by addn. of anthraquinone or anthraquinone mono:sulphonate before, during or after gluing with alkaline phenol] formaldehyde] resin |
DE4133445C2 (en) * | 1991-10-09 | 1995-04-20 | Fraunhofer Ges Forschung | Process for the production of chipboard and medium density fibreboard |
-
1994
- 1994-09-02 DE DE4431316A patent/DE4431316C1/en not_active Expired - Fee Related
-
1995
- 1995-08-14 EP EP95112789A patent/EP0699510B1/en not_active Expired - Lifetime
- 1995-08-14 AT AT95112789T patent/ATE166278T1/en not_active IP Right Cessation
- 1995-08-14 DE DE59502232T patent/DE59502232D1/en not_active Expired - Lifetime
Cited By (3)
Publication number | Priority date | Publication date | Assignee | Title |
---|---|---|---|---|
DE102005019627B3 (en) * | 2005-04-26 | 2006-10-26 | Fraunhofer-Gesellschaft zur Förderung der angewandten Forschung e.V. | Medium density fiberboards, of digested ligno cellulose refined into fibers, contains a bonding agent giving a low emission of volatile organic compounds |
US8623501B2 (en) | 2010-03-04 | 2014-01-07 | Basf Se | Lignocellulose materials having good mechanical properties |
US8920923B2 (en) | 2010-03-04 | 2014-12-30 | Basf Se | Lignocellulose materials having good mechanical properties |
Also Published As
Publication number | Publication date |
---|---|
EP0699510A3 (en) | 1996-07-10 |
DE59502232D1 (en) | 1998-06-25 |
EP0699510A2 (en) | 1996-03-06 |
DE4431316C1 (en) | 1996-05-02 |
ATE166278T1 (en) | 1998-06-15 |
Similar Documents
Publication | Publication Date | Title |
---|---|---|
DE69703552T2 (en) | METHOD FOR PRODUCING COMPOSITES FROM LIGNOCELLULOSE MATERIAL | |
EP0012169B1 (en) | Multi-layered, mainly aminoplast-bound particle or fibre board | |
EP0006486B1 (en) | Process for reducing the emission of formaldehyde by fibre boards | |
EP0699510B1 (en) | Method for reducing the formaldehyde emission from lignocellulosic products | |
DE69630076T2 (en) | A catalytic composition and method for curing a urea-formaldehyde resin | |
EP0144985B1 (en) | Method of decreasing the formaldehyde emission of veneered chip and fibre boards | |
EP0341569B1 (en) | Process for the preparation of composite materials with a lowered formaldehyde emission | |
EP1266730B1 (en) | Method of manufacturing moisture resistant fibreboards | |
EP0788866B1 (en) | Method for the fabrication of particle boards and fibreboards with low formaldehyde content using tannin based binders | |
EP2567798B1 (en) | Use of polyamine in wood materials for reducing the emission of aldehydes and/or acids | |
DE1653167A1 (en) | Process for the production of chipboard with reduced subsequent release of formaldehyde | |
EP0307812A2 (en) | Multilayered plywood and its manufacture | |
EP0436485B1 (en) | Method for accelerating the hardening of aminoplast adhesives and wooden products using the same | |
EP0740673B1 (en) | Binders for the production of lignocellulose-containing mouldings | |
DE3733630A1 (en) | METHOD FOR PRODUCING WOOD MATERIALS | |
EP0570435B1 (en) | Process for the production of wood-fibre boards | |
DE2219164A1 (en) | METHOD FOR MANUFACTURING LIGHT PANELED PANELS | |
DE10121651B4 (en) | Process for reducing the release of formaldehyde | |
EP0023002B1 (en) | Process for reducing the emission of formaldehyde by chip boards | |
DE2615288B1 (en) | Process for the production of chipboard | |
WO2015086034A1 (en) | Wood product or natural fiber composite material product and use of a formaldehyde-free amino- and amide resin based on glyoxylic acid esters for the production thereof | |
DE19820833A1 (en) | Recycling used chipboard and fiberboard materials | |
AT164256B (en) | Method for gluing materials, in particular plywood and veneer wood | |
WO2015032458A1 (en) | Wood product or natural fiber composite material product and use of a formaldehyde-free aminoplast resin for the production thereof | |
WO2024046878A2 (en) | Process for producing a woodbase material board provided with a flame retardant |
Legal Events
Date | Code | Title | Description |
---|---|---|---|
PUAI | Public reference made under article 153(3) epc to a published international application that has entered the european phase |
Free format text: ORIGINAL CODE: 0009012 |
|
AK | Designated contracting states |
Kind code of ref document: A2 Designated state(s): AT BE DE FR |
|
PUAL | Search report despatched |
Free format text: ORIGINAL CODE: 0009013 |
|
AK | Designated contracting states |
Kind code of ref document: A3 Designated state(s): AT BE DE FR |
|
17P | Request for examination filed |
Effective date: 19960612 |
|
GRAG | Despatch of communication of intention to grant |
Free format text: ORIGINAL CODE: EPIDOS AGRA |
|
GRAG | Despatch of communication of intention to grant |
Free format text: ORIGINAL CODE: EPIDOS AGRA |
|
GRAH | Despatch of communication of intention to grant a patent |
Free format text: ORIGINAL CODE: EPIDOS IGRA |
|
17Q | First examination report despatched |
Effective date: 19980123 |
|
GRAH | Despatch of communication of intention to grant a patent |
Free format text: ORIGINAL CODE: EPIDOS IGRA |
|
GRAA | (expected) grant |
Free format text: ORIGINAL CODE: 0009210 |
|
AK | Designated contracting states |
Kind code of ref document: B1 Designated state(s): AT BE DE FR |
|
REF | Corresponds to: |
Ref document number: 166278 Country of ref document: AT Date of ref document: 19980615 Kind code of ref document: T |
|
ET | Fr: translation filed | ||
REF | Corresponds to: |
Ref document number: 59502232 Country of ref document: DE Date of ref document: 19980625 |
|
PLBQ | Unpublished change to opponent data |
Free format text: ORIGINAL CODE: EPIDOS OPPO |
|
PLBQ | Unpublished change to opponent data |
Free format text: ORIGINAL CODE: EPIDOS OPPO |
|
PLBI | Opposition filed |
Free format text: ORIGINAL CODE: 0009260 |
|
PLBF | Reply of patent proprietor to notice(s) of opposition |
Free format text: ORIGINAL CODE: EPIDOS OBSO |
|
26 | Opposition filed |
Opponent name: PFLEIDERER INDUSTRIE GMBH & CO. KG Effective date: 19990219 Opponent name: KRONOPOL SP. Z.O.O. Effective date: 19990219 |
|
PLBF | Reply of patent proprietor to notice(s) of opposition |
Free format text: ORIGINAL CODE: EPIDOS OBSO |
|
PLBF | Reply of patent proprietor to notice(s) of opposition |
Free format text: ORIGINAL CODE: EPIDOS OBSO |
|
29U | Proceedings interrupted after grant according to rule 142 epc |
Effective date: 20001206 |
|
29W | Proceedings resumed after grant [after interruption of proceedings according to rule 142 epc] |
Effective date: 20010803 |
|
PGFP | Annual fee paid to national office [announced via postgrant information from national office to epo] |
Ref country code: FR Payment date: 20010828 Year of fee payment: 7 |
|
PGFP | Annual fee paid to national office [announced via postgrant information from national office to epo] |
Ref country code: BE Payment date: 20010829 Year of fee payment: 7 Ref country code: AT Payment date: 20010829 Year of fee payment: 7 |
|
PGFP | Annual fee paid to national office [announced via postgrant information from national office to epo] |
Ref country code: DE Payment date: 20011012 Year of fee payment: 7 |
|
RDAH | Patent revoked |
Free format text: ORIGINAL CODE: EPIDOS REVO |
|
RDAG | Patent revoked |
Free format text: ORIGINAL CODE: 0009271 |
|
STAA | Information on the status of an ep patent application or granted ep patent |
Free format text: STATUS: PATENT REVOKED |
|
27W | Patent revoked |
Effective date: 20020718 |
|
PLAB | Opposition data, opponent's data or that of the opponent's representative modified |
Free format text: ORIGINAL CODE: 0009299OPPO |