ES2537642T3 - Procedure to reduce the emission of volatile organic compounds from wood derivatives - Google Patents

Abstract

Process for manufacturing wood derivatives coated with lignocellulose, in particular agglomerate plates, fiber plates or OSB plates, which includes the steps: a) contacting crushing products containing lignocellulose with adhesives, b) pressing the mixture from a) under heat treatment, also being added as an additive between the contact of stage a) and the pressing of stage b) and / or after the pressing of stage b), to reduce the emission of compounds volatile organic compounds or highly volatile organic compounds, in particular unsaturated or saturated aldehydes, at least one additive, chosen from alcohols, if necessary in combination with a catalytically effective amount of acid and / or an antioxidant, characterized in that the additives they are on a substrate material and this substrate material that the additive presents is applied between stages a) and b) and / or after stage b) on s crushing products containing lignocellulose or on the derivative of pressed wood.

Description

DESCRIPTION

Procedure to reduce the emission of volatile organic compounds from wood derivatives

The present application relates to a process according to claim 1 for manufacturing lignocellulose-based wood derivatives 5, in particular chipboard, fiber plates or OSB plates (of oriented fibers), but also of plywood and wood solid, in which these derivatives of the wood are treated with at least one additive during manufacturing, to reduce the emission of volatile organic compounds, but also of highly volatile organic compounds, such as unsaturated or saturated aldehydes. More precisely are these alcohol additives, which if necessary are added in combination with catalytically effective amounts of acid. Alternatively or additionally, a treatment with suitable antioxidant agents can be carried out. In another aspect, the present application is directed to the use according to claim 11 of alcohols, if necessary in combination with catalytically effective amounts of acid and / or antioxidant agent as additives to reduce VOC emission, in particular saturated and unsaturated aldehydes , in the manufacture and use of wood derivatives from lignocellulose. Finally, the application is directed to wood derivatives which can be obtained with the process corresponding to the invention according to claim 14 and / or to wood derivatives manufactured using the additives with reduced emission of volatile organic compounds.

State of the art

 twenty

The emission of volatile organic compounds (VOC) from wood derivatives (HWS) is a serious problem under the aspect of the increasing use of woody products in interior spaces. To volatile organic compounds belong, in addition to saturated and unsaturated aldehydes, all volatile organic substances whose retention time in the gas chromatograph is between C6 (hexane) and C16 (hexadecane). VOCs are not a homogeneous substance class, but a collection of compounds. Among others, they are organic acids, saturated and unsaturated aldehydes, alcohols, carbonic acids, terpenes, aliphatic and aromatic hydrocarbons and many more. In addition there are the so-called highly volatile organic compounds (VVOC), among which are, for example, formaldehyde or formic acid, which also occur during the manufacture of wood derivatives. The emission of these volatile and highly volatile wood ingredients or components of wood product adhesives, including solid wood and wood-derived plates 30, represents a continually growing problem, due to the strictest limit values and / or greater awareness of end consumers.

The term "aldehydes", as used now, includes saturated and unsaturated aldehydes, provided that they are in the classes corresponding to volatile organic compounds or highly volatile organic compounds.

To avoid the emission of these volatile organic compounds, various proposals have been made so far. Thus, EP 185 231 describes the use of oxidizing agents to reduce emissions. In addition, various proposals were made to reduce the emission of formaldehyde. However, due to the heterogeneity of volatile organic compounds, it is desired to avoid or reduce the emission of these compounds in a particularly durable manner. Of course, it is difficult to transform the heterogeneous class of VOCs, which are partly toxic, through a single chemical reaction.

Therefore, a reduction in volatile organic compounds and highly volatile organic compounds from wood, in particular volatile wood ingredients, is still desired, during manufacturing, but also during use. It should be taken into account in this regard that the emission of VOC, but also that of VVOC, occurs not only during the manufacturing process, but also during use through the decomposition of wood ingredients, including through the chemical decomposition of adhesives used VOC emissions are of course based primarily on releases due to the wood of the so-called primary emission of volatile wood ingredients, such as terpenes or chemical decomposition products, such as acetic acid and the so-called secondary and / or tertiary emissions, by example higher aldehydes, such as pentanal or higher carbonic acids. These decomposition products result from long-term oxidation processes of wood ingredients, such as fatty acids but also lignin, cellulose and hemicellulose. 55

They are typical transformation products that occur among others during the storage and mechanization of wood or crushing products, for example pentanal and hexanal. As especially critical compounds, saturated and unsaturated aldehydes should be classified in the heterogeneous group of VOCs and VVOCs. These are not only toxic, but partly also carcinogenic. In addition, the same 60 have to be classified as critical in the olfactory aspect. The aldehydes are formed among others during the manufacture of wood derivatives, as explained above and are released in particular from OSB plates (of oriented fibers) with delay by fragmentation of unsaturated fatty acids and due to the use of adhesives that They contain aldehyde. Precisely for OSB plates in the construction sector this is a great inconvenience, since in this application OSB plates do not have a coating that reduces emissions and are built in 65

large quantities, in particular as plate surface, referred to the total amount of cubic meters of the room or building.

Similar problems arise with an emission of aldehydes when light wood derivatives are used, such as MDF (medium density fibreboard) light and superlight for thermal insulation. These emit 5 more intensely aldehydes, for example cyclic aldehydes. Then problems result both due to the amount emitted and also due to the toxicity of the compounds.

As already explained, also due to the adhesives used, volatile organic compounds, such as aldehydes, are released during manufacturing or then during use. Among the adhesives currently being treated in the manufacture of wood derivatives, such as OSB plates, with dense fiber plates, etc., are aminoplast adhesives, such as urea-formaldehyde adhesives (UF adhesives), melamine adhesives. urea-phenol-formaldehyde (MUPF adhesives) or melamine-urea-formaldehyde adhesives (MUF adhesives). Other adhesives that are typically used in wood derivatives include diisocyanate-based adhesives (PDMI), polyurethane adhesives, phenol-formaldehyde adhesives (PF adhesives) and / or tannin-formaldehyde adhesives (TF adhesives) or mixtures of the same. In this regard, aminoplast adhesives are mainly used in the field of fiber plates. Here we present a release of aldehydes and other VOCs and VVOCs, both during the manufacture of wood derivatives and also after their manufacture or during their use. During the manufacture of fiber plates, for example, during the thermomechanical treatment of cellulose-containing materials, a partial chemical decomposition of the wood. The volatile organic compounds and highly volatile organic compounds that then result, such as aldehydes and acids, then emit during the subsequent manufacturing process or during the subsequent use of manufactured wood derivatives. They can also have a negative influence on bond strength and thereby negatively influence the properties of manufactured wood derivatives. 25

Various approaches have already been made to limit these problems of the emission of volatile organic compounds, including aldehydes. WO 2010/144969 A1 describes the manufacture of perlite and fiber-based composite plates. In EP 1 852 231 the use of various additives is proposed, including among others the use of maleic anhydride or similar compounds. The use of reducing and / or oxidizing agents is also known. In addition, an increase in the pH value is proposed, for example by adding alkaline hydroxides.

 WO 2006/032267 processes for the reduction of unsaturated aldehydes in woods containing fatty acids are known. They dissociate, inhibit or oxidize the fatty acid ester contained in wood. For this purpose it is generally proposed to use antioxidants, alkaline compounds or oxidizing agents. Of course, these additives are treated before drying the freshly cut solid wood and / or before or during the manufacture of the wood particles. It is not foreseen or it is considered disadvantageous to add them after or during the contact of the products of the crushing with adhesives and in particular after the wood derivatives are pressed. 40

The need therefore remains for processes to reduce the emission of volatile organic compounds, but also of highly volatile organic compounds, in particular also of aldehydes, as well as organic acids, in particular of fatty acid degradation products from wood derivatives.

 Four. Five

The present invention thus has as a basic task to provide lignocellulose coated wood derivatives, in particular chipboard, fiber plates or OSB plates, but also plywood and solid wood plates, which have a greater reduction or avoidance of emissions of volatile organic compounds (VOC) and highly volatile organic compounds (VVOC). In this regard, the emission of these volatile or highly volatile organic compounds, including saturated and unsaturated aldehydes, must be clearly reduced, both during manufacture and also during subsequent use. In addition, the olfactory nuisance that results due to these volatile and / or very volatile organic compounds must also be reduced. In particular, it must be taken into account in this regard that no substance is used or generated that harms the manufacturing process of these wood derivatives. It is also an important aspect that does not significantly increase the manufacturing costs of wood derivatives. The agents themselves then used should not cause toxicity or be carcinogenic, 55 but they should react as widely as possible with the heterogeneous classes of volatile organic substances or highly volatile organic compounds and / or should avoid their formation from integral parts. of wood derivatives.

Description of the invention 60

The task of the present invention is solved by adding certain additives at certain times during the process corresponding to the invention to manufacture or mechanize lignocellulose wood derivatives. These additives are alcohols, if necessary in combination with a catalytically effective amount of acid and / or certain antioxidant agents. 65

That is, in a first aspect the present application is directed to a process for manufacturing lignocellulose coated wood derivatives, in particular chipboard, fiber plates, OSB plates or plywood plates, according to claim 1.

Contrary to most of the procedures used so far, not only chemical modifications of the emitting VOCs and VVOCs are intended herein, but also above all prevent the transformation and / or degradation of the initial substances in the wood. That is, the additives used in the context of the invention prevent the degradation of fatty acids and / or esters of fatty acids. In addition, aldehydes are transformed, if necessary, formed by transformation reactions in the corresponding non-emissive compounds.

 10

The compounds obtained by the reaction are no longer volatile and thereby no longer contribute to VOC and VVOC emissions or aldehyde emissions or the toxicity of the compounds that are formed is clearly reduced. In this regard, the emission is clearly reduced in particular after manufacturing, that is, during daily use.

 fifteen

The process corresponding to the invention includes the steps

a) contacting crushing products containing lignocellulose with adhesives;

b) press the mixture from a) under heat treatment,

 twenty

and it is characterized in that the additives are on a substrate material and this substrate material presenting the additive is applied between stages a) and b) and / or after stage b) on the crushing products containing lignocellulose or on the derivative of pressed wood.

That is, in the context of the invention the additives are applied on a substrate material. This is particularly so for antioxidants as additives corresponding to the invention. Such an application can be carried out by known measures and procedures. These procedures include an application by spraying, impregnation, immersion or extension on the substrate material.

In this regard, the additive can be found on one side or on both sides of the substrate material. 30 Preferably the additive is then found on the face oriented towards the wood derivative. The substrate material can be for example a layer of cellulose, paper or the like. The substrate material can then be applied according to the invention before pressing the mixture or after pressing it on the wood derivative. When it comes to solid wood used as a derivative of wood, the substrate material presented by the additive correspondingly is applied to solid wood. 35

Additionally, the wood derivative can be covered by the substrate material and thereby further prevent the emission of VOCs and VVOCs.

The substrate material may then be constituted transparent or with a decorative motif. The substrate materials may be usual overlay products or 100% cellulose paper, for example, used in the wood-derived manufacturing sector, for example panels. If necessary, after applying the additive on the substrate material, the additive can be dried at room temperature before joining the substrate material presented by the additive with wood derivatives or crushing products containing lignocellulose with additives. Four. Five

For example, the substrate material can be soaked with the additive, sprinkled or impregnated in another way. This substrate material is then applied before spreading it on the conveyor belt and is scratched after spreading it, but before pressing. In an alternative way, the substrate material is applied after pressing on the wood derivative and for example it is scraped, or it is otherwise joined with the wood derivative. It is then preferred that in wood-derived plates, such as OSB plates, fiber plates, plywood or agglomerate plates, but also solid wood, the substrate material is applied on both sides of the wood derivative. In this regard it is preferred that the additive be at least on the side oriented to the wood derivative.

 55

In another embodiment, the additive is added to the crushing product containing lignocellulose before pressing and after spreading or laying. Preferably, the additive is then added before pressing but after defibration or defrosting and in particular after drying.

The additive can then be applied in the form of an aqueous solution or as a powder mixture directly after the pressing process, for example by sprinkling nozzles on one or both sides of the derivative of the manufactured wood. Alternatively an application can be made by roller.

In another embodiment, the additive can be added dosed as a solution or as a powder to the crushing products containing lignocellulose or to the mixture of crushing products containing lignocellulose and adhesive. Then the metered addition can also be made before the dryer, but after 65

shredder or deflector. The instant of the dosed addition then depends on the form of the additive, for example as an aqueous solution or as a powder.

For example, the additive can be provided during the manufacture of OSB plates only in some areas of the plate. Preferably the additive is then provided at least in the areas of the wood derivative plate that constitute the cover layer, such as an OSB plate. In addition, the additive can be applied both in part before pressing and also after pressing with a substrate material.

It is especially preferred that wood derivatives are those made from wood chips, wood strands or wood fibers as crushing products containing lignocellulose. 10

In particular it is preferred that the wood derivative is an OSB plate. Wood derivatives may be coated, if necessary additionally with known layers, such as a varnish layer, decorative layer or wear layer. The additives can then also be found in these layers or only in them. That is, the substrate material can be configured as a decorative layer, varnish layer, wear layer or correspondingly in sub-layers.

In an alternative embodiment, the wood derivative is solid wood and the additives are applied or provided by known procedures on the wood derivative.

 twenty

The additives to be used according to the invention are, on the one hand, alcohols, in particular polyols. It is particularly preferred that these alcohols are provided together with a catalytically effective amount of acid, to enable an acid catalyzed reaction of the alcohols. The alcohols can then react for example with aldehydes that are formed to constitute acetals.

 25

Fats and oils are esters of polyalcohols, usually glycerin, with saturated and unsaturated fatty acids. By oxidative degradation of these fats and fatty acids during the pressing process under high temperatures, for example aldehydes appear. When glycerin or other alcohols, in particular polyalcohols, are added with a small amount of an acid for the acid catalysis reaction, the aldehydes react to form acetals. Then, when it comes to glycerin, three hydroxyl groups are available, for example. It is therefore preferred to add polyols as additives.

Another reaction pathway, in addition to acetal formation, is esterification with fatty acids from wood. This is usually subjected to acid catalysis. The fatty acids are then esterified and with this the degradation of the fatty acids to form VOC and VVOC is prevented. 35

It is therefore especially preferred that when alcohol is used as an additive acid is added for the acid catalysis reaction of the alcohols. Small amounts of acid are sufficient in this regard, since it acts catalytically.

 40

Preferred alcohols are polyalcohols, in particular glycerin or alkylene glycols, such as ethylene glycol, propanediol, butanediol, etc.

As another additive an antioxidant agent can be used. Antioxidant agents allow to capture radicals, which are formed, for example, at high temperatures or with light. At high temperatures or with light, for example 45 hydroxyl radicals appear, which have the ability to rapidly oxidize other substances. In this way VOCs and VVOCs are easily formed from the natural components in the wood. Antioxidant agents, in particular antioxidant agents chosen from ascorbic acid, vitamin E or butylhydroxytoluene (BHT) have the ability to capture such radicals and thereby prevent the formation of VOCs or VVOCs from wood components . These antioxidant agents are provided and / or applied within the framework of the invention in / on the substrate material.

It is preferred that the additives be added in an amount of 0.5 to 5% by weight of solid substance, referred to atro wood (absolute drying).

 55

When the additives corresponding to the invention were used in the manufacture or machining of wood derivatives, such as OSB plates or MDF plates, but also plywood and solid wood, a clear reduction in VOCs and / or VVOCs was surprisingly observed , including aldehydes. Additionally, a clearly lower emission of other volatile organic compounds was also observed. A reduction in emission is achieved both during manufacturing and also during subsequent use. This is more surprising because it could not be assumed that due to the plurality of reactive compounds that exist in the wood these additives could effectively reduce the emission of VOCs and / or VVOCs and in particular of the aldehydes.

The lignocelluloses, such as those derived from wood or the products of their crushing, can be both coniferous and hardwoods. Also mixtures of these two types of

wood. Preferably the wood chips, strands or wood fibers of coniferous wood came. The wood derivatives that can be manufactured by the manufacturing process corresponding to the invention are manufactured according to claim 14. Then the process can be further complemented by other methods known to the specialist to reduce the emission of volatile organic compounds or highly volatile organic compounds , as aldehydes. 5

The wood derivatives (HWS) may preferably be wood chipboard chipboard wood, OSB wood strand fibers, wood veneer plywood plates and wood fiber plates, in particular MDF plates, fiber fibers wood. However, under the expression "wood derivatives" plywood is also included and in particular also solid wood. Preferably, the 10 wood derivatives are OSB plates and light and super light MDF plates.

Under lignocelluloses are understood as materials containing lignocellulose, such as wood. The crushing products that are then obtained from lignocellulose include in particular wood strands, wood chips, wood fibers, but also wood veneer. fifteen

The adhesives used in the process corresponding to the invention include as adhesives phenol-formaldehyde adhesive, isocyanate-based adhesive, urea-formaldehyde adhesive, melamine-urea-formaldehyde adhesive, melamine-urea-phenol-formaldehyde adhesive, adhesive of tannin-formaldehyde or a mixture thereof. twenty

In another aspect, the present application is directed to the use of a composition containing an alcohol, as defined herein, if necessary in combination with catalytically effective amounts of an acid and / or an antioxidant agent, as defined herein, to reduce the emission of VOCs and / or VVOCs, in particular saturated and unsaturated aldehydes, during manufacture and during the use of lignocellulosic wood compounds. This use is characterized in that the additive can be added or applied during the manufacturing process of the wood derivative. The additive is then added or applied, as explained above, with the help of a substrate material.

 The use is particularly advantageous when adhesives chosen from the phenol-30 formaldehyde adhesive, isocyanate-based adhesive, urea-formaldehyde adhesive, melamine-urea-formaldehyde adhesive, melamine-urea-phenol-formaldehyde adhesive are used , tannin-formaldehyde adhesive or a mixture thereof.

The additives are particularly suitable for use at least in the cover layer of OSB plates or wood fiber plates.

Preferably the additives are then used in an amount of 0.5% by weight up to 5% by weight of solid substance referred to atro wood.

 40

Finally, the present application is directed in another aspect to wood derivatives that can be obtained with the process corresponding to the invention. These wood derivatives are in particular fiber plates, in particular light and superlight MDF plates or OSB plates, but also solid wood.

With the aid of the process corresponding to the invention, it is possible, by dosing some additive, to reduce the emission of VOC and / or VVOC from wood derivatives during manufacture, but also during use. When substrate materials are used, it is also possible to suppress the emission of VOC and / or VVOC by coating.

In addition, the additives used in the context of the invention have in particular a long-term advantageous action 50 to suppress VOC or VVOC emissions, since the additives existing in the substrate material or in the cover layer also avoid long-term the formation and emission of VOC or VVOC.

The invention will now be described in more detail with the aid of examples, without the invention being limited thereto. 55

Example 1: Manufacturing of OSB with low emission

Using glued strands from the ongoing manufacturing (12% of MUPF as an adhesive), a reference plate and two plates were made using the glycerin and ascorbic acid additive. These plates were pressed at 60 continuation to reach a format of 10 mm x 300 mm x 300 mm and an apparent density of 530 kg / m3. The parameters for pressing are found in the table shown below. Before pressing, the glued strands were mixed with the corresponding additive. In addition, a part of the additive was injected after pressing on the surface of the plate. Sample A contains the glycerin additive dosed up to 5% by weight. By adding additive A, some drops of hydrochloric acid were added for catalysis. Sample B contains 65 the ascorbic acid additive with a proportion of 1% by weight based on atro wood.

Table 1

 pressing diagram pressing stage

    Pressure [N / mm2] time [s] T [ºC]

 one

 2 60 200

 2

 1 60 200

 3

 0.2 10 200

After cooling the plate, it was closed in an air tight manner and kept for analysis.

 5

Example 2: Determination of VOC emission from OBB

Material and methods

Material 10

Samples were manufactured from the OSB plates previously obtained with the dimensions 210 x 210 x thickness mm3. From the edge of these samples, a band 7 mm wide was taken in each case. This was then separated into two samples with a length of 95 mm. One of the samples was provided oriented with the upper face and the other with the lower face to the air flow in the heat extractor. The results were expressed as the average value of these two measurements.

Method: heat extraction

For a qualitative and comparative investigation of the emission potential of structurally similar materials, the heat extraction method is suitable.

The different samples were characterized with a so-called heat extractor (TE1, Gerstel, Mülheim a.d. Ruhr, Germany). It is about a glass tube with a relatively small volume of approx. 25.9 cm3, which is in the heat extractor. A continuous nitrogen flow (100 ml / min-1) is conducted through the entire system, which is conducted at regular time intervals through an absorber, as in conventional tests in a test chamber. According to DIN ISO 16000-6: 2004, they were analyzed in a GC-MS with thermo-desorption and cold trap. The entire system was operated at room temperature (23 ° C). Scherer and colab's method was described. (Conservation of clean air of hazardous substances, 2006, 66 (3), 87-93). To always achieve the same conditions, that is, reproducible, a steel sample holder was used, which releases a potentially emitting sample surface of approx. 7.1 cm2. Figure 1 shows the heat extractor, the sample holder and the sample dimensions. The conditions during the heat extraction are summarized in Table 2. The sampling of 11 volumes of air was performed 10 minutes after the samples were introduced into the heat extractor. The results are expressed as quantity of substance referred to the volume of sampling (μg m-3).

 35

Table 2: Conditions during heat extraction

 Parameters

 Characteristic

 Temperature in ºC

 RT

 Mass flow in ml min-1

 100

 Chamber volume in m3

 0.00002586

 Air change rate in h-1

 232.0

 Sample area in m2

 0.00075

 Space load in m2m-3

 29.1

 Specific surface ventilation speed in m3-2 h-1

 8.0

The test results are represented in table 3.

40

Table 3: Results

 µg / m3

 Sample 0 Sample A Sample B

 aldehydes

 681 153 42

 saturated aldehydes

 651 140 31

 unsaturated aldehydes

 18 3 1

 hexanal

 577 124 26

 2-heptenal

 12 3 1

 2-octenal

 6 0 0

It can be clearly seen in samples A and B with the corresponding additive that aldehydes are clearly avoided. In particular, saturated aldehydes, but also unsaturated ones, have been clearly reduced. 5

The results are shown graphically again in Figure 1.

Claims (15)

1. Process for manufacturing wood derivatives coated with lignocellulose, in particular agglomerate plates, fiber plates or OSB plates, which includes the steps: a) contacting crushing products containing lignocellulose with adhesives, 5 b) press the mixture from a) under heat treatment, also adding as an additive between the contact of stage a) and the pressing of stage b) and / or after the pressing of stage b), to reduce the emission of volatile organic compounds or highly volatile organic compounds, in particular unsaturated or saturated aldehydes, at least one additive, chosen from alcohols, if necessary in combination with a catalytically effective amount of acid and / or an antioxidant agent, 10 characterized in that the additives are on a substrate material and this substrate material presenting the additive is applied between stages a) and b) and / or after stage b) on the crushing products containing lignocellulose or on the derived from pressed wood. 2. Method according to claim 1, 15 characterized in that the additive is a polyalcohol, in particular glycerin, ethylene glycol, ethanediol or propanediol. 3. Method according to one of claims 1 or 2, in which acid is also provided for the acid catalysis reaction of the alcohols with aldehydes or fatty acids. twenty 4. Method according to claim 1, characterized in that the antioxidant agent is ascorbic acid, vitamin E or butylhydroxytoluene. 5. Method according to one of claims 1 to 4, 25 characterized in that the substrate is a cellulose-containing material, such as paper, that is coated or impregnated with the additive by one or both sides. 6. Method according to claim 5, characterized in that the substrate material is applied by scraping on the crushing product containing lignocellulose before pressing and after spreading or laying it and / or after pressing on the derivative of the pressed wood. 7. Method according to one of claims 1 to 4, characterized in that the additive is applied after step b) on one or both sides on the derivative of the pressed wood and / or is provided in at least the crushing products containing lignocellulose and forming the cover layer. 8. Method according to one of the preceding claims, characterized in that the additive is added to the crushing products before pressing but after defibration or defrosting. 9. Method according to one of the preceding claims, characterized in that the wood derivatives are those that are manufactured from wood chips, wood threads or wood fibers as crushing products containing lignocellulose. Four. Five 10. Method according to one of the preceding claims, characterized in that the amount of additive added is between 0.5 and 5% by weight of solid substance referred to atro wood (absolute drying).  fifty 11. Use of an additive containing an alcohol, if necessary in combination with catalytically effective amounts of acid and / or an antioxidant agent, to reduce the emission of volatile organic compounds or highly volatile organic compounds, in particular saturated and unsaturated aldehydes, during the manufacture and use of lignocellulose wood derivatives, characterized in that the additive can be provided or applied during the manufacturing process of the derivative of the wood with the help of a substrate material containing an additive. 12. Use according to claim 11, characterized in that the additive is used at least in the cover layer of OSB plates or wood fiber plates. 60 13. Use according to one of claims 11 or 12, characterized in that the additive is applied dosed in an amount of 0.5 to 5% by weight of solid substance referred to atro wood.  65 14. Wood derivative that can be obtained by a method according to one of claims 1 to 10. 15. Wood derivative according to claim 14, in which the wood derivative are fiber plates, in particular light and superlight MDF plates or 5 OSB plates.