WO2016142483A1 - Method for producing a wood chip material and curing agents used therein for aminoplasts - Google Patents

Abstract

The invention relates to a method for producing wood chip materials, comprising the following steps: a) providing a first lignocellulose-containing material in the form of wood particles; b) gluing the first lignocellulose-containing material with a composition comprising at least one aminoplast resin and at least one first curing agent, wherein the first curing agent was obtained via hydrothermic and/or mechanical development of a second lignocellulose-containing material, and wherein second lignocellulose-containing material comes from another raw material as the first lignocellulose-containing material; and c) pressing to form a wood chip material. The invention also relates to a wood chip material that can be obtained via said method, and to the use of a hydrothermically and/or mechanically developed lignocellulose-containing material as a curing agent for aminoplast resins in a method for producing a wood chip material.

Description

 Process for producing a wood chip material and used therein

 Hardener for aminoplasts

The present invention relates to a process for the preparation of

Wood chipboard materials, wood chipboard materials obtainable therefrom and the use of hardeners, which are obtainable from hydrothermally and / or mechanically digested lignocellulose-containing material, for aminoplast resins.

Chip-based materials, so-called wood chip materials, consist of

shredded wood material that can be pressed into single or multilayer boards. The classification of wood chipboard is usually according to EN 309. Important classification characteristics are

Manufacturing process (extruded or flat pressed),

Surface texture (raw, ground, press-coated), the shape and size of the wood materials used (wood shavings, wood flakes, wood wafers, wood strands), the board structure (single or multi-layered) and the intended use.

Since the massive wood composite is largely eliminated in wood chip materials, these plates in the direction of the plate plane, ie in the direction of the length and width of the plate, almost the same swelling and shrinkage properties.

Wood chip materials find, for example, in the construction industry as an insulating, constructive or cladding element, in the furniture industry and as

Flooring use.

In the production of wood chips materials a high recycling of the wood can be ensured. Thus, in addition to forest wood, residual wood from industry and used wood are used. - -

Chipboard materials are produced from finely divided wood material of various types of wood with the addition of natural and / or synthetic binders as well as other substances. For processing the wood material, cutting processes are used to recover wood particles. Examples of wood particles are wood flakes, wood strands, wood wafers, wood chips and wood chips. Subsequently, the wood particles are usually dried, glued with a composition (glue liquor) containing a binder and arranged in one or different layers (scattering). Finally, the scattered wood material is pressed under pressure and temperature to the respective desired wood chip material.

The expert distinguishes between wood chip materials and

Wood fiber materials. Wood chipboard materials and wood fiber materials as well as their production processes differ fundamentally from each other.

Wood fiber materials contain wood as the main component

Fiber material. This fibrous material is obtained by steaming or cooking (e.g., in a precooker or digester) wood material and by chemical or mechanical disruption (e.g., in a racer) to single fiber, fiber bundles, or fiber debris. In contrast, wood chip materials as the main component contain chip material, i. Pieces of wood. The chip material is obtained by merely crushing wood material. A treatment by steaming, boiling or by chemical or mechanical disruption as in the

Defibration is currently not.

Binders for the production of wood chip materials may have one or more constituents. Usually consist or contain binders for the production of wood chipboard resins.

Synthetic resins are known to those skilled in principle. Synthetic resins are

For example, in Rompps Chemie-Lexikon, 7th edition, Frankh'sche Verlagshandlung Stuttgart, 1973, page 1893 described. An important group of synthetic resins are condensate resins. These harden by condensation reactions, which often - -

Water is split off. The condensate resins include, for example

Phenol-formaldehyde resins and aminoplast resins.

Aminoplast resins have proved to be particularly practical in connection with the production of wood chip materials. Usually contains one

Wood chipboard material at least one aminoplast resin as binder. Aminoplast resins are commonly used in wood chipboard, the

lignocellulosic parts or wood particles to connect. In this case, a single aminoplast resin or mixture of different aminoplast resins can be used.

Aminoplast resins are known in the art and e.g. in "Ullmanns Enzyklopadie der technischen Chemie", 4th Edition, Volume 7, pp 403ff .. Aminoplast resins can be obtained by condensation of an amino, imino or amide group-containing component with a carbonyl compound

Starting materials for aminoplast resins are, for example, urea and / or melamine (as the amino-containing component) and formaldehyde (as

Carbonyl). In the latter case, the amino groups containing

Component usually precondensed in a first step with the carbonyl compound to a certain degree. Depending on whether in the first step, e.g. only melamine or only urea is used as the amino-containing component, one obtains a so-called melamine resin or a urea resin. Such melamine and / or urea resins may in particular form the main constituents of aminoplast resins. In a second step, often as curing

referred to, the aminoplast resin can then be crosslinked throughout. Resins formed from urea and formaldehyde are also referred to as

Urea formaldehyde resins. Resins formed from melamine and formaldehyde are referred to as melamine-formaldehyde resin. - -

Whenever aminoplast resins are mentioned here or elsewhere, they are meant to include aminoplast resin compositions. Aminoplast resins and / or aminoplast resin compositions may also contain water.

The curing of synthetic resins, in particular of aminoplast resins, can be carried out, for example, by addition of acidic catalysts. Usually conventional hardeners come into consideration. Hardeners and their reaction to initiate the curing reaction are described, for example, in "Wood Materials and Glues: Technology and Influencing Factors" by M. Dunky and P. Niemz, Springer-Verlag, 2013, pages 265 to 270. In principle, the typical hardeners for aminoplast resins have in common, These acids catalyze or initiate the curing reaction Examples of conventional curing agents are strong organic acids, inorganic acids such as sulfuric acid and phosphoric acid, salts that are acidic in water such as aluminum chloride and aluminum nitrate (U.S. also referred to as acid salts), salts which generate an acid (also referred to as acid-generating salts) by reaction with components of the synthetic resin, preferably with formaldehyde, such as ammonium phosphate, ammonium nitrate, ammonium sulfate and ammonium chloride, and mixtures of the aforementioned substances.

Formaldehyde may be harmful to human or animal health and may cause allergies, skin, respiratory or eye irritation. In chronic exposure, it may even be carcinogenic. Therefore, it is desirable

To produce wood chip materials with a reduced formaldehyde content. This is in particular with regard to the use of wood chip materials for

Production of furniture or important as a floor covering.

For hardening especially of aminoplast resins, various hardeners are known to the person skilled in the art: - -

WO 02/068178 A2 describes a method for bonding laminated products with an aminoplast resin, wherein a hardener containing acid, an acid salt and / or an acid-generating salt and a Polmyerdispersion is used.

WO 2005/030895 Al describes binder systems, in addition to

Aminoplastharzen and N-functionalized copolymers also contain at least one acid, an acidic salt and / or an acid-generating salt.

WO 2007/012615 Al describes a hardener composition for

An aminoplast resin comprising an acid, an acidic salt and / or an acid-generating salt and an aminoplast resin dispersion having a residual activity of less than or equal to 100 J / g.

A disadvantage of the hardener compositions listed in the prior art is that the curing of the resin is difficult to control when using strong acids as a hardener, since the curing can begin even on addition of the acid.

In order to avoid this undesirable precuring, the so-called hardening precoating method has been proposed in the prior art, in which first the acid is applied to the preliminary or intermediate product of the wood pulp and then the gluing with a synthetic resin is carried out. However, a disadvantage of this is the economic outlay caused by the additional

Process steps.

Moreover, strong acids contribute more to the unwanted hydrolysis of the glue joint. Often, additional buffer systems must be used to reduce these disadvantages, but in turn can lead to insufficient curing of the resin. The same applies to the use of acid salts, in which the curing can also begin with the addition of the acidic salts. Another disadvantage of acid-generating salts is that these salts are usually free - -

Formaldehyde need to form the corresponding strong acid, which then contributes to the curing of the resin. In this respect, binder compositions (glue fleets) containing hardener systems based on acid-generating salts require an increased formaldehyde content. Normally, this formaldehyde is not permanently bound and can be slowly released after completion of the manufacturing process. Thus, these hardener compositions are not optimal for the production of wood chip materials having a reduced formaldehyde content.

Furthermore, the use of ammonium salts can also be problematic for environmental, economic and safety aspects. For one thing

Ammonium compounds before, during and after production is a potential source of ammonia, on the other hand is the use of

To critically assess ammonium chloride in terms of recycling and thermal disposal. Furthermore, ammonium nitrate poses a risk during storage because it is fire-promoting and explosive.

Another concern is that when using ammonium compounds or when added directly after the production of the wood chip material acid can continue to be formed or free strong acid remains in the wood chip material. This acid can lead to the hydrolysis of the glue joint, which can have a negative effect on the strength and swelling properties of the wood chip material.

On the basis of the above-described prior art and its disadvantages, it was an object of the invention to provide a method which employs an improved alternative hardening system. In particular, it was an object of the invention to provide a method which allows

To produce wood chip materials with a reduced formaldehyde content. - -

This object is achieved by a method according to claim 1, a wood chip material according to claim 21 and a use according to claim 22 or 23.

Advantageous embodiments of the invention are described in the dependent claims and are explained below as the general inventive concept in detail.

The inventive method for producing a wood chip material comprises the following steps: a) providing a first lignocellulose-containing material in the form of wood particles;

 b) adding the first lignocellulosic material with a

 A composition comprising at least one aminoplast resin and at least one first curing agent, wherein the first curing agent

 hydrothermal and / or mechanical digestion of a second lignocellulosic material, and wherein the second lignocellulosic material is derived from a different raw material than the first lignocellulosic material;

 c) pressing to a wood chip material.

Optionally, further method steps may be carried out before, after and / or between the steps a) to c). Optional steps may be, for example, heating in a preheat container, crushing, storing, mixing, adding further substances, spreading or drying the material used or obtained in steps a) to c).

Surprisingly, it was found that by the use of a hardener of hydrothermally and / or mechanically digested lignocellulosic Material, the problems listed above, known from the prior art problems can be largely avoided or reduced.

Since the aminoplast resin used in the process according to the invention may also contain other hardeners, the hardener obtained by hydrothermal and / or mechanical pulping of lignocellulose-containing material according to the invention is referred to herein as the "first hardener".

It is advantageous that the use of the first hardener can be integrated in a simple manner in conventional processes of the wood industry for the production of wood chip materials. There are no time-consuming intermediate steps or process interruptions required.

It is also advantageous that the inventively used first hardener

Low cost and readily available. It is obtainable by hydrothermal and / or mechanical digestion of lignocellulose-containing material. In a preferred embodiment of the invention, the first hardener is made

Biomass containing lignocellulose, won. If biomass is mentioned here, then so are very different plants, plant parts, fruits and mixtures thereof, in particular plant waste from agriculture or the

Meant wood industry. The utilization of this biomass for the production of the first hardener is thus an ecologically very relevant advantage, since biomass one

represents renewable raw material. A particular embodiment of the invention makes it possible to plant waste that only or not at all for

End use are suitable to use for the preparation of the first hardener.

Overall, by the inventive method an improved

Cascade use of vegetable raw materials can be achieved.

Another practical and economic advantage of the first hardener is that it can be produced in a particularly simple and cost-effective manner. Process for the hydrothermal and / or mechanical digestion of lignocellulosic Material are known to those skilled in the art, for example from the manufacture of fibreboard. It is also of practical importance that the first hardener can be added to the binder composition (glue liquor) in a particularly simple manner and is compatible with it, for example in the case of the use of strong acids sometimes practiced in the prior art, as used, for example, in US Pat

Hardener Vorstrichverfahren be used, not possible.

Furthermore, the inventive method allows a reduced use of the above-mentioned chemicals. By using the first curing agent according to the invention, the need for free formaldehyde and / or the amount of conventional hardeners, such as. As acid-generating salts are significantly reduced. Thus, the first hardener is an environmentally friendly alternative and / or supplement to the conventional hardeners explained above.

Without wishing to be limited to any particular scientific theory, this surprising effect of the first hardener appears to be explained by the fact that one or more acids are released during the hydrothermal and / or mechanical digestion. This at least one acid seems to contribute to the curing of the resin.

The at least one acid released during the hydrothermal and / or mechanical digestion also appears to be a volatile acid. As a result, this acid does not remain or only for a short time in the glue joint of the finished wood chip material. This short residence time of the acid hydrolysis of the glue joint can be largely avoided by this acid. When acid is mentioned here, it may mean a single acid or mixtures of different acids.

Important parameters for wood chip materials are swelling, transverse tensile strength and water absorption. Surprisingly, in practical experiments

found out that these parameters are present in wood chip materials produced by the Processes according to the invention have been improved. In particular, when using the first hardener according to the invention, which is obtainable by hydrothermal and / or mechanical pulping, the amount of conventional hardener can be reduced and in some cases even dispensed with, without resulting in any deterioration of these parameters. For example, the

Transverse tensile strength of the wood chipboard materials produced can be improved. Furthermore, the swelling and / or water absorption of the produced

Wood chip materials are significantly reduced.

By "lignocellulosic material" it is meant plant material containing lignocellulose, lignocellulose according to the invention containing cellulose and / or hemicellulose and lignin.

"Cellulose" is an unbranched polysaccharide consisting of several hundred to ten thousand cellobiose units, which in turn consist of two molecules of glucose linked by a β-1,4-glycosidic linkage.

"Hemicellulose" is a collective name for various components of plant cell walls. Hemicelluloses are branched

Smaller chain length polysaccharides - usually less than 500 sugar units - made up of different sugar monomers. Hemicellulose is composed essentially of various sugar monomers such as glucose, xylose, arabinose, galactose and mannose, which sugars may have acetyl and methyl substituted groups. They have a random, amorphous structure and are readily hydrolyzable. Xylose and arabinose consist for the most part of sugar monomers with five

Carbon atoms (pentoses). Mannose or galactose consist mainly of sugar monomers with six carbon atoms (hexoses). "Lignins" are amorphous, irregularly branched aromatic macromolecules, which occur in nature as part of cell walls and there the

Cause lignification of the cell. They are made from substituted

Constructed phenylpropanol units, show a lipophilic character and are insoluble in room temperature in neutral solvents, such as water. Precursors of lignin are, for example, p-coumaryl alcohol, coniferyl alcohol and sinapyl alcohol. The molecular weights of lignin are usually between 10,000 and 20,000 g / mol.

"Hydrolysis" within the meaning of the invention may, in particular, the cleavage of a

mean (bio) chemical compound by reaction with water. In particular, it is possible in this case to formally deliver a hydrogen atom to the one gap piece and the remaining hydroxyl group to the other gap piece.

If this is referred to as "wood chip material" then it will be

According to the invention, a wide variety of chip-based materials is understood, which consist of wood or contain wood. Wood chipboard (chipboard in the broader sense) refers to a product group in the field of wood materials, which are made of wood particles and at least one binder by means of heat and pressure. Another product group in the field of engineered wood, not covered by the term "wood chipboard" as used herein, is the wood fiber materials. The latter includes fiberboard such as the medium density (MDF) and high density (HDF) fiberboard Wood-chip materials, the wood used for the production of the fiberboard is used up to the wood fiber,

Fiber bundles or fiber fragments open-minded. For the expert wood chip materials and wood pulp are two fundamentally different

Material categories to be distinguished.

Basically, the expert knows different wood chip materials. Examples include particleboard, flat-plate, single-layer, multi-layer, lightweight flat, extruded, extruded (ET - - -

Extruded Tubular], Extruded Solid (ES),

Plastic coated decorative flat pressed sheets (MFB - Melanin Faced Board), chipboard molded parts or OSB (Oriented Strand Board). The

Classification of chipboard can be done according to DIN EN 312, whereby the

Particleboard in strength and moisture resistance can differ. OSB boards can be classified according to their use according to EN 300. Such wood chip materials can be used for example for laminates, floor coverings,

Worktops, table tops, pallets and / or wooden molds can be further processed. Wood chip materials, their production and requirements for these are also in "Paperback of wood technology", A. Wagenführ, F. Scholz, Carl Hanser Verlag, 2nd edition, 2012 on pages 143 to 146 described.

According to one embodiment of the invention, the wood chip material is a

Chipboard plate. Preferably, the wood chip material is a chipboard or OSB board. Practical experiments have shown that the method according to the invention and the described embodiments are particularly suitable for

Production of pressed chipboard materials, in particular for the production of chip and OSB boards are suitable.

Preferably, the wood-chip material, or its intermediate or intermediate product, consists essentially of lignocellulose-containing material and

"Substantially" means in this case to 90 wt .-%, 95 wt .-%, 99% by weight or 99.9 wt .-%, each based on the total weight of the wood chip material.

However, it is also possible that the wood chip material, or its precursor or intermediate, contains other substances. For example, wetting and / or separating agents can be added for an improved pressing process. Furthermore, antifungal agents or fire retardants may be added. As a result, the finished lignocellulosic wood chip materials can meet special requirements. Such requirements have already been mentioned above and are known to the person skilled in the art. In particular, such further substances in the Processes according to the invention are added before, during and / or after one of the steps a) to c).

Step a) of the method according to the invention provides for the provision of

Wood particles in front. If wood particles are mentioned here, then this means any wood particles that can be used for the production of wood chip materials. Wood particles can be any crushed products of

Lignocellulose containing materials. Wood particles, as used herein, are not wood fibers.

Since the hardener used according to the invention also contains lignocellulose, the wood particles used in step a) are referred to herein as "first lignocellulose-containing material." The material used to produce the hardener is referred to as a "second lignocellulose-containing material".

According to the invention, the first differs from the second lignocellulose-containing material as explained below.

For the production of wood-chip materials according to the method according to the invention and its embodiments, a first lignocellulose-containing material which is in the form of wood particles is used in step a). Depending on the nature of the wood chip material, the first lignocellulose-containing material can be produced by comminuting lignocellulose-containing materials. According to the invention, the first lignocellulosic material is provided in the form of wood particles, i. H. it can contain or consist of wood particles. Wood particles, as used herein, may contain wood or be made of wood. Examples of wood particles are finely divided wood material, wood chips, wood strands, wood wafers, wood flakes and wood chips. Usually, the wood particles for wood chip materials are obtained by cutting processes. In an optional step, the

Wood particles are dried or stored before further processing. It is also possible to admix further substances to the first and / or second lignocellulose-containing material. In principle, various methods are known to those skilled in the art to produce wood chip materials by compression. According to one embodiment of the invention, the wood particles glued in step b) are pressed in step c) into a wood chip material. Preferably, step c) is a hot pressing. Optimum results can be achieved if the press factor during hot pressing is from 2 to 10 s / mm, preferably from 3 to 6 s / mm. Under press factor here in particular the residence time of the lignocellulosic

Wood chip material understood in seconds per millimeter thickness or thickness of the finished pressed lignocellulosic wood chip material in the press.

Suitable temperatures for the compression in step c) of the process according to the invention or one of its embodiments are temperatures of 150 ° C to 250 ° C, preferably from 160 ° C to 240 ° C, particularly preferably from 180 ° C to 230 ° C. At temperatures in these ranges, the process can be carried out particularly economically.

For economic and procedural reasons, it has proved to be advantageous if during pressing a specific pressing pressure [active pressure on the plate surface] of 50 to 300 N / cm ² , is used. Such pressures ensure a particularly good bonding of the lignocellulose-containing particles together. In addition, a high strength of the lignocellulosic wood chip materials can be achieved with such a pressure.

Since the process according to the invention is a process for producing wood chips from the wood particles used in step a) (referred to herein as "first lignocellulosic material"), this process does not involve defibration, steaming, cooking or chemical and / or mechanical pulping (For example, in a refiner) of the first lignocellulosic material, as practiced for example in the production of wood fiber boards. In step b) of the process according to the invention, the first lignocellulose-containing material is glued with a composition which comprises at least one aminoplast resin and at least one first hardener. If this is called "Beieimen", then it may be wholly or partially wetting with a

Composition containing a binder ("binder-containing

Compositions of this type are also referred to by the person skilled in the art as "glue liquor". According to the invention, the binder is an aminoplast resin. In particular, the uniform distribution of the binder-containing particles can also be found

Mean composition on the wood particles. The application of the binder-containing composition can be carried out, for example, by impregnation or spraying, in particular in a blowline.

The inventive method comprises the addition of wood particles having a composition comprising at least one aminoplast resin and at least one first curing agent. This can be achieved in a variety of ways. In particular, the curing agent can be added to the aminoplast resin before and / or during the addition of the aminoplast resin to produce the composition. According to one embodiment of the method according to the invention, a previously prepared mixture of aminoplast resin and first hardener is used as a composition for adding the wood particles and applied to the wood particles. According to this

Embodiment of the method, so the wood particles with a

A composition containing an aminoplast resin and a first hardener is glued by applying a previously prepared mixture of aminoplast resin and first hardener to the wood particles.

The inventive method, however, also such embodiments are included, in which the curing agent is added to the aminoplast resin only during Beieimens and thus the composition according to the invention is formed only in situ while Beieimen. This can be done in particular by the fact that when Beimimen the wood particles, the aminoplast resin and the first hardener separated from each other, possibly with - other additives or binders to which wood particles are applied. In the process, the aminoplast resin and the curing agent mix to form a composition which contains an aminoplast resin and a first hardener, for example, the aminoplast resin may be applied in a first step and the first hardener applied to the wood particles in a second step become.

Conversely, it is also possible, in a first step, first the first hardener and then in a second step, the aminoplast resin on the wood particles

applied. A simultaneous application of aminoplast resin and first curing agent by two separate application devices, such as nozzles, on the wood particles is possible. Accordingly, a further embodiment of the

Procedure that the wood particles with a composition that a

Contains aminoplast resin and a first hardener to be glued by the

Aminoplast resin and the first hardener are applied separately to the wood particles.

The amount of binder used in the pasting is preferably 0.1 to 20 wt .-%, in particular 1 to 16 wt .-%, more preferably 4 to 14 wt .-%, based on the dry weight of wood (solid resin / atro). For many applications, it is particularly practical if the binder in an amount of 0.1 to 15 wt .-% based on the dry weight of wood (solid resin / atro) is used.

Basically, the method according to the invention or one of its

Embodiments suitable for a variety of binder-wood particle combinations. According to the invention, at least one aminoplast resin is used as the binder. Alternatively or additionally, other synthetic resins, in particular phenoplasts, vinyl acetates, isocyanates, epoxy resins and / or acrylic resins in

can be used according to the invention. In one embodiment of the invention, the binder is an aminoplast resin and one or more

Hardeners. Examples of aminoplast resins are urea-formaldehyde resins (UF), melamine-reinforced urea-formaldehyde resins (MUF), melamine-urea-phenol-formaldehyde resins (MUPF), polymeric diisocyanates (PMDI) and / or isocyanates or mixtures thereof. In practice, particularly good results can be achieved with urea-formaldehyde resins (UF), melamine-reinforced urea-formaldehyde resins (MUF) or mixtures thereof.

Preferably, the aminoplast resin is obtainable by condensation of an amino group-containing component with a carbonyl compound. In the

Carbonyl compound is preferably formaldehyde. In the

Amino-containing component is preferably melamine and / or urea. More preferably, the aminoplast resin is a melamine resin or a urea resin, especially a melamine-formaldehyde resin or a urea-formaldehyde resin.

 The composition (glue liquor) used in the process according to the invention also contains at least one first hardener. Advantageously, this contains

Binder 0.1 to 15 wt .-% of the first hardener, in particular 0.5 to 10 wt .-%, based on the solid resin content of the aminoplast resin.

As used herein, the term "hardener" is a term familiar to one of ordinary skill in the art of making chipboard material Hardeners are catalysts that catalyze, ie, promote or initiate a curing or crosslinking reaction without themselves being consumed in the process the person skilled in the art are known

Catalysts that reduce the reaction rate by lowering the

Increase the activation energy of a chemical reaction without being consumed. The curing of aminoplast resins is carried out by

Acid catalysis. The acid, which acts as a hardener, initiates or drives the curing or crosslinking reaction without being consumed. Hardeners are therefore to be distinguished from the starting materials of the aminoplast resin crosslinking reaction, which react with each other during the aminoplast resin curing and are therefore consumed. Likewise, hardeners are also from

Additives, such as diluents such as lignin, to distinguish, which are functionalized by groups in a position to polymerize into the aminoplast resin. Such additives, which during the Aminoplastharz curing - - polymerize and thereby abreact and can be consumed are not covered by the term "hardener", as used here.

The first hardener provided according to the invention is based on lignocellulose-containing material. It is obtained by hydrothermal and / or mechanical pulping of such a lignocellulose-containing material. According to one embodiment, the first hardener used according to the invention therefore contains hydrothermally and / or mechanically digested lignocellulose-containing material or consists thereof.

According to the invention, the hardener is obtained from a second lignocellulose-containing material which differs from the first lignocellulose-containing material described above used in step a). This difference exists

especially in origin and / or the underlying raw materials.

According to the invention, provision is made in particular for the second lignocellulose-containing material to come from a different raw material than the first lignocellulose-containing material. The first and second lignocellulose-containing material can thereby

represent different raw materials or have been produced or obtained from different raw materials. According to one embodiment, the difference in the raw materials in the plant species or the composition of plant species from which the two lignocellulose-containing materials are obtained. According to another embodiment, the difference in the raw materials in the genus or the compilation of plant species from which the two lignocellulose-containing materials are obtained. The terms plant species and plant genus are to be understood according to the usual botanical definition (taxon and genus).

The first lignocellulosic material according to the invention in the form of

Provided wood particles, that is, that at least one raw material from which comes the first lignocellulosic material is wood. The second lignocellulosic material may be derived from a different species of wood than those used as raw material - - was used for the first lignocellulosic material. However, the raw materials for the first and second lignocellulose-containing material preferably differ in that the second lignocellulose-containing material originates from a raw material that is different from wood, in particular from tree wood.

In a preferred embodiment of the invention, the second is

lignocellulosic material selected from the group consisting of annuals, crops, grasses, foliage, cereals, their constituents and waste, or mixtures thereof. Crop is in particular straw, wheat, rye, barley, oats, millet, corn, miscanthus, rice, their constituents, their waste and / or mixtures thereof understood. When referring to "annual plants", they mean plants and / or their constituents, which

Contain lignocellulose and from the germination of their seed to the fertilization of their flowering and the maturity of the new seed need a growing season and die after the maturity of the new seed. In a particularly preferred

Embodiment will be one or more of these selected second

lignocellulosic materials hydrothermally and / or mechanically

open minded. This hydrothermally and / or mechanically digested material can then be used as the first hardener.

The use of the above-described lignocellulose-containing materials for

Preparation of the first hardener has proven to be economically advantageous. The plants mentioned are easy to cultivate and can be processed easily and in a few process steps. For example, the processing of plant waste not only ensures a low-cost raw material, but also an improved cascade use of plant raw materials. In contrast, the use of wood, especially tree wood, as a raw material for the production of the first hardener, the much longer cultivation times, the significantly increased workload and the cost of processing the wood would be disadvantageous. It has therefore proved to be advantageous according to the invention, when the

Production of the hardener according to the invention, so-called "second" lignocellulose-containing material of the in step a) of the invention - -

A method for producing the wood chip material used, so-called "first" lignocellulosic material distinguishes.

For these reasons, it is provided according to a particular embodiment of the invention that the second lignocellulosic material contains no wood, especially no tree wood, and also does not come from such raw materials.

According to the invention, the raw materials enumerated above for the second lignocellulose-containing material (see above and claims 14 and 15) do not fall under the

Generic term wood.

In one embodiment of the invention, the second lignocellulose-containing material can be used without comminution for the hydrothermal and / or mechanical digestion. In another embodiment of the invention, the second lignocellulosic material for hydrothermal and / or mechanical pulping may also be pre-shredded. Preferably, this is dry

pre-shredded. The comminuted second lignocellulosic material may have an average particle size - determined by the mesh size of the screen - of 20 μηι to 20 mm, preferably 0.05 μπι to 1 mm and more preferably 0.4 μπι to 0.4 mm.

The average particle sizes stated here are average sieve diameters which are determined by the particles passing through a defined mesh size of a sieve, Methods for the determination of particle sizes are generally known to the person skilled in the art, for example sieve analysis in accordance with DIN 66165 For example, in the screening process, the portion which has passed through the upper sieve but is no longer able to pass through the sieve considered remains in the sieve process can be weighed and represented as a percentage in the form of a particle distribution, from which the mean sieve diameter can also be calculated - - according to DIN 66165. For small particle sizes or particle fractions, microscopic methods can be used to determine the particle size.

Preferably, the comminuted second lignocellulosic material has a

Particle size distribution in the at least 70, 80, 90 or 95 wt .-% of the material has a mesh diameter of 20 μιτι to 20 mm, preferably from 0.05 μπι to 1 mm, more preferably from 0.1 μιτι to 0.4 mm, determined through the mesh of the screen. This particle size distribution can be present before or after the mechanical disruption. Preferably, this relates

Particle size distribution on the material, which has already been mechanically crushed and is subjected only to a hydrothermal and / or mechanical pulping.

In one embodiment, the particle size or average particle size can be determined such that the particles of the second lignocellulose-containing material, a sieve with a mesh size of 20 mm, preferably of 1 mm, more preferably of 0.4 mm and particularly preferably of 0.2 mm happen. In practice, this means that according to one embodiment of the invention

Particle fractions can be used, resulting from particles that pass through these mesh sizes. In this embodiment, the mean particle size is determined by a "maximum size" of the particles through the mesh widths defined above These particle sizes may be present before or after the hydrothermal and / or mechanical pulping Preferably, these particle sizes refer to the material which has already been mechanically comminuted and only a hydrothermal and / or mechanical pulping is subjected.

According to a further embodiment of the invention, the comminuted second lignocellulose-containing material has a particle size distribution in which at least 70, 80, 90 or 95% by weight of the material has a screen diameter of less than 20 mm, preferably less than 1 mm, less than 0.4 mm or less than 0, 2 mm, each determined by passing a sieve with a corresponding mesh size. - -

The term "dry matter content" is that component of a substance that remains after subtracting the mass of the water contained in it, which means that the dry matter content and the water content of a substance are 100% In one embodiment of the invention, the first hardener may have a dry weight of from 5 to 25% by weight, in particular from 10 to 20% by weight, based on the

Total weight of the material have.

During hydrothermal and / or mechanical digestion of the second lignocellulosic material, acid may be released. According to a preferred embodiment, the first hardener in step b) contains an acid which has been released by the hydrothermal and / or mechanical digestion of the second lignocellulose-containing material. This is particularly advantageous because the hydrothermally and / or mechanically digested second lignocellulosic material directly the acid used as a catalyst in the

Curing reaction (as described above) can act, contains and does not have to be released first. In one embodiment of the invention, the second lignocellulose-containing material releases at least one acid during the hydrothermal and / or mechanical digestion in the presence of water and / or heat. Surprisingly, it has been found that preferably weak and / or volatile acids are released during the hydrothermal and / or mechanical digestion. In a preferred embodiment of the invention is during the hydrothermal and / or mechanical

Digested formic acid and / or acetic acid released. Since formic acid and / or acetic acid are weak acids, the disadvantages of the strong acids described above can thus be largely avoided.

"Hydrothermal" as used herein means that the digestion is under

Influence of water and elevated temperature takes place. The water can come from the materials used or added. Preferably - - Water is added, especially in the form of water vapor. According to a preferred embodiment of the invention, the digestion mentioned in step b) is a simultaneous hydrothermal and mechanical digestion.

Without wanting to be tied to a scientific theory, the

Release of the acid to the good hydrolyzability of the hemicellulose

to be due. So led comparative experiments with microcrystalline

Cellulose, which has been subjected to the conditions of hydrothermal and / or mechanical pulping, not to release the acid. Basically, the ß-l, 4-glycosidic bonds of the glucose molecules are very stable. Thus, the hydrolysis of the cellulose requires drastic conditions, such as strongly acidic or strongly alkaline conditions or more specific enzymes. One reason why the microcrystalline cellulose does not release acid during the hydrothermal and / or mechanical digestion could thus be that this digestion is not sufficiently acidic or alkaline.

This also seems to explain why, for the preparation of the first hardener, the second lignocellulosic material described above is much better suited than, for example, tree wood. One reason for this could be that the second lignocellulose-containing material used according to the invention, in particular the above-mentioned plants, have a higher average hemicellulose content than, for example, tree wood, in particular softwood.

According to one embodiment of the invention, the release of the acid contributes to the curing of the resin. This is especially the case when the resin can be cured by acid catalysis. The acid catalysis curable resins include, in particular, aminoplast resins. According to one embodiment of the invention, the during the hydrothermal and / or mechanical

Digestion liberated acid to harden in the binder-containing

Composition containing aminoplast resin. - -

In one embodiment of the invention, the acid released during the hydrothermal and / or mechanical disruption has a molecular weight of from 40 g / mol to 500 g / mol, in particular from 40 g / mol to 250 g / mol. In another embodiment, the acid is a Brönsted acid having a pK _a of 2 to 8, especially 3 to 6. Preferably, the acid is a carboxylic acid having a chain length of 1 to 5 carbon atoms. Examples of carboxylic acids are

Formic acid, acetic acid, propanoic acid, butanoic acid, pentanoic acid and derivatives thereof. Examples and properties of Bronsted acids are described, for example, in "Basic Knowledge in Chemistry", C. Mortimer, Thieme, 7th Edition, 2001, pages 281 to 290. pK _a is the negative decadic logarithm of the acid constant K _a under standard conditions (See also "Organic

Chemistry ", Jonathan Clayden, Nick Greeves, Stuart Warren, OUP Oxford, 2012, pages 163-181.) The smaller the pK _a value, the stronger the acidity is, if an acid has multiple dissociation levels (eg, H2SO4: pK _a 1st step: -3, 2nd step: 1.92), the pK _a value here refers to the pK _a value of the 1st dissociation step The pK _a values of some important Brönsted acids can be found in following table.

- -

- -

In one embodiment of the invention, the carboxylic acid is a weak acid. If here or elsewhere weak acids are mentioned, it means that pK _{a is} equal to or greater than 3. With a pK _a of the Bronsted acid of less than 3, the binder can be attacked by the acid and is at least partially hydrolyzed.

Practical experiments with the first hardener to be used according to the invention have resulted in markedly reduced hydrolysis of the glue joint if the acid which is released during the hydrothermal and / or mechanical pulping and can contribute to the curing of the aminoplast resin is a weak acid. One reason for this could be that the low acidity of the weak acids makes the hydrolysis less pronounced than with acids from conventional hardeners and / or strong acids. Conventional hardeners, like

For example, ammonium salts are still after completion of the

Holzspanwerkstoffs able to release more acids that can diffuse into the glue joint and hydrolyze them.

In another embodiment of the invention, the carboxylic acid is a volatile acid. Examples of volatile acids are formic acid or acetic acid. The

Volatility of the acid can further contribute to the better stability of the glue joint. One reason for this could be that a volatile acid remains in the glue joint for a shorter time than acids from conventional hardeners. This shorter retention time can reduce or even prevent unwanted hydrolysis of the glue joint.

The first hardener is available by hydrothermal and / or mechanical pulping. Suitable temperatures for the hydrothermal and / or

mechanical disruption of the second lignocellulosic material

Temperatures of 120 to 180 ° C, preferably 130 to 170 ° C and particularly preferably 140 to 160 ° C. - -

For procedural reasons, it is particularly practical if the hydrothermal and / or mechanical digestion of the second

lignocellulosic material at a pressure of 3 to 10 bar, in particular at 4 to 8 bar, takes place.

In one embodiment of the invention, the duration of the hydrothermal and / or mechanical digestion is 2 seconds to 40 minutes, in particular 5 seconds to 30 minutes.

In a further embodiment of the invention, the hydrothermal and / or mechanical digestion can be carried out in a preheating container, digester and / or refiner. Preferably, the hydrothermal and / or mechanical digestion is carried out in a digester and / or pressure reactor.

Alternatively or additionally, the hydrothermal and / or mechanical

Digestion preferably carried out in a refiner. Furthermore, the hydrothermal and / or mechanical digestion may comprise the following steps:

(i) hydrothermal digestion of the second lignocellulose-containing

 Material in a digester and / or pressure reactor;

 (ii) mechanical digestion by comminution of the second

 lignocellulosic material from step (i) in a refiner.

The terms cooker, pressure reactor and refiner are known to those skilled in the wood industry. By "cooker" is meant, in particular, a device which is suitable for the hydrothermal digestion of the second lignocellulose-containing material. "Pressure reactor" is any reaction vessel which constitutes a sealed, delimited space in which a pressure can be built up and that for carrying out the hydrothermal Digestion of the second

lignocellulosic material is suitable. The term "refiner" is understood by the person skilled in the art to mean a device for comminuting or defibrating wood, in particular under the effect of pressure. Examples of refiner which are used in practice are Southerland - -

Refiner with hollow axle and a movable grinding disc, Fritz refiner with 10 grinding discs, Calfin refiner or hydrorefiner.

The hydrothermal digestion in step (i) can be carried out at a temperature of 120 to 180 ° C, in particular at 140 to 160 ° C. Suitable pressures for the

hydrothermal digestion are between 3 to 8 bar, especially at 4 to 6 bar. The duration of the digestion can be between 5 and 40 minutes. An opening time of 30 minutes has proved to be advantageous. Good results can be achieved if step (i) is carried out in the presence of water. The use of water vapor has proved to be particularly practical.

The mechanical digestion in step (ii) takes place in a refiner. Particularly suitable process temperatures are in a range of 140 to 180 ° C,

in particular from 150 to 160 ° C and at a pressure of 1 to 8 bar, in particular at 4 to 6 bar. The duration of the mechanical digestion can be 2 seconds to 5 minutes, in particular 5 seconds to 3 minutes. In another

Embodiment of the invention can be carried out step (ii) in the presence of water, in particular water vapor.

In a further embodiment of the invention may optionally be further

Process steps before, after or between steps (i) and (ii) are performed. Optional steps may include heating in a preheat container, crushing, storing, mixing, spreading, adding further substances, or drying the lignocellulosic material or a mixture containing the

lignocellulosic material from step (i) and / or (ii).

In practice, it has proved to be advantageous if the binder-containing composition also contains a second hardener in addition to the first curing agent according to the invention. The second hardener may be a conventional hardener described above, in particular an ammonium salt. Examples of suitable ammonium salts are ammonium nitrate, ammonium phosphate, ammonium chloride and - -

Ammonium sulfate. Upon reaction with formaldehyde, these ammonium salts form their corresponding acid which acts as an acid catalyst to cure the resin. Examples include nitric acid, phosphoric acid, hydrochloric acid,

Sulfuric acid.

It has been found that the first hardener according to the invention is particularly compatible with aminoplast resins and the conventional hardeners conventionally used there. Furthermore, binder compositions containing an aminoplast resin, a first hardener according to the invention and a second hardener have proven to be stable.

In a further embodiment of the process according to the invention, the binder-containing composition contains 0.1 to 4% by weight of ammonium salt,

in particular 0.5 to 3.0 wt .-%, based on the solid resin content of the resin. In a preferred embodiment of the process, the ammonium salt is

Ammonium nitrate and the resin is an aminoplast resin. It is particularly advantageous that the proportion of the conventional second hardener can be reduced by using the first hardener. In a particularly preferred embodiment of the invention, the second hardener can be saved up to half or more if the second hardener is used in combination with the first hardener according to the invention.

Basically, this also means that, for example, in comparison with the sole use of ammonium salts as curing agents for amino resins, significantly less ammonium salt has to be added to the process. As a result of the reduced ammonium salt content, the process also requires less formaldehyde. This allows wood chip materials with reduced

Formaldehyde content can be obtained. The same applies to other, explained in the beginning conventional hardener. - -

The invention further relates to lignocellulose-containing wood chip materials which have been produced or obtainable by the above-described method according to the invention or its embodiments. Such a wood chip material can be used particularly well for the production of a laminate, flooring, a worktop, table top, a piece of furniture or a pallet.

In addition, the invention also relates to the use of the first hardener according to the invention, which was obtained by hydrothermal and / or mechanical pulping of a second lignocellulose-containing material, in an above

described inventive method for the preparation of

Wood chip materials. In this case applies to the features of the use of the above to the features of the method or its embodiments executed accordingly. In particular, according to a preferred

Embodiment of the inventive use of the first hardener an acid free. In a further embodiment of the use according to the invention, the first hardener releases acetic acid and / or formic acid.

The above-mentioned advantages of the method according to the invention also apply to the inventive use of the first hardener. In particular, by the use of the first hardener, the strength of conventional

Wood chipboard even while reducing the amount of

conventional hardeners are kept or even improved. Also, by using the first hardener itself, while reducing the amount of conventional hardeners, an improvement in swelling behavior and / or water absorption can be achieved. One reason for this could be that the acid released during hydrothermal and / or mechanical digestion is free and volatilises more rapidly than conventional hardeners. This creates a neutral glue joint, which positively influences the characteristics of the wood chip material described above. - -

The invention will be described in more detail by way of example with reference to exemplary embodiments.

example 1

First, the preparation of the first hardener will be described. When

Lignocellulose-containing material was used straw.

Version 1:

 In the first variant, the digestion of the lignocellulose-containing material was carried out in a discontinuous single-disc refiner (Sprout Waldron). The refiner was filled with the material and steam (160 ° C) was introduced into the cyclone. The material remained at 160 ° C and 6 bar for about 2 minutes in the refiner, then the cyclone was opened and the material was transported out via the screw and a 2.5 mm valve within about 5 minutes.

Variant 2:

 In the second variant, the lignocellulose-containing material was pre-shredded dry in an Ecopulser (Krause Maschinenbau GmbH) and screened (Retsch AS 200). The particle fraction smaller than 0.6 mm was then in a pressure reactor (Büchiglasuster Cyclon 300) at 160 ° C and 5 to 6 bar below about 1: 5

Diluted with water for about 30 min.

The materials thus available were subsequently used as the first hardener.

Example 2

Plate tests were carried out under the following conditions:

Plate thickness: 14 mm

Target density: 600 kg / m ³ - -

Pressing factor: 9.3 s / mm

Press temperature: 200 ° C

 Coating degree: 8.0% by weight, based on the total mass of the chipboard

First lignocellulosic material: wood shavings

 First Hardener: The Material Obtained in Example 1 (Variant 1 or 2)

Second hardener: ammonium nitrate

Press: Laboratory press from Siempelkamp

Several pressings were carried out with different dosages of the first hardener and / or the second hardener. The first hardener used was the lignocellulose-containing material prepared according to Example 1 in dosages of 1, 3, 6 and 10% by weight of the solid, based on the solid resin fraction (hereinafter% solid / FH) Quantities of 1, 1.5, 2 and 3% fixed / FH.

The treated lignocellulosic material was added to the sizing liquor

Aminoplast resin added. Following the plate pressing, the transverse tensile strength, swelling and water absorption were determined. For this purpose, specimens of geometry 50 × 50 × 14 mm were first cut to size. Each test specimen was measured by means of a digital thickness probe before the test, and the mass determined and used to calculate the density.

transverse tensile strength

 The transverse tensile strength was determined according to EN 319. To this end, each test specimen was bonded by means of a hot melt adhesive with two aluminum yokes on the top and bottom and then pulled apart after cooling on the testing machine (Zwick Zmart.Pro) at a constant test speed of 1 mm / min.

The force leading to the break in the middle of the specimen was recorded and the resulting transverse tensile strength over the specimen area was calculated [N / mm ² ].

Thickness swelling - -

The determination of the thickness swelling after 24 hours of water storage was carried out according to DIN EN 317. The test specimens were stored for this purpose at a water temperature of 20 ° C for 24 h under water. Subsequently, the increase in thickness was determined relative to the starting thickness and the percentage thickness swelling was calculated.

water absorption

 The water absorption was determined on the samples of thickness swelling, so also after 24 h water storage. For calculation, the weight was measured after these 24 hours and the water absorption was then calculated according to the following formula:

Wasseraufhah «[%]« ₁₀₀

The results were evaluated by means of Excel, Minitab or DesignExpert.

The following are the test results of reference plates that only

Ammonium nitrate and plates containing the first hardener (digested material of Example 1) and ammonium nitrate as the second hardener. The plates were made with the following hardener compositions:

Trial plate Production variant First Hardener Second Hardener

 First hardness (material of (ammonium nitrate) (from Example 1) Example 1) Weight% by weight [solid / FH]

 % ffest / FHl

 Reference 1 - - 1.5%

Reference 2 - - 3%

 1 1 3% 1.5%

2 1 6% 1.5%

3 1 10% 1.5%

4 2 1% 2%

5 2 1% 1% - -

The reference plates 1 and 2 were made without the addition of the first hardener. The test plates 1 to 3 were produced with the first hardener of variant 1 from example 1 and the test plates 4 and 5 were produced with the first hardener of variant 2 from example 1.

The test panels were each made at least twice and determines the transverse tensile strength, the swelling and the water absorption. The measurements below are averages of at least two plates.

Result of transverse tensile strength:

 The transverse tensile strength was determined for reference plates 1 and 2 and experimental plates 1 to 3. The results are shown in Diagram 1.

0.50

 o, os

 0.00

 Reference 1 Reference 2

Test plates gram 1: transverse tensile strength [N / mm ² ] = transverse tensile strength measured according to

EN 319 - -

From Diagram 1 it can be seen that the transverse tensile strength of the experimental plates 1 to 3 corresponded approximately to the transverse tensile strength of the reference plate 2. By adding the material digested in Example 1 as the first hardener, the amount of ammonium nitrate could be reduced by half and still maintain the good transverse tensile strength.

Result of swelling:

 The swelling was determined on reference plate 2 and experimental plates 4 and 5. The results are shown in Diagram 2.

 Diagram 2: swelling [%] = thickness swelling measured according to DIN EN 317

The measurement showed a reduced swelling for the experimental plates 4 and 5 despite reduced content of ammonium nitrate. , ,

Result of water absorption:

 The water uptake was determined for reference plate 2 and experimental plate 4. The results are shown in Diagram 3.

 Reference 2

 f experimental plates

Diagram 3: Water absorption [%] = relative increase in mass to the plate before

 Swelling in percent

It turns out that when using the first hardener according to the invention, the water absorption could be reduced, and despite reduced

Ammonium nitrate content.

Claims

claims Anspruch [en] A method of making a wood chipboard comprising the steps of: a) providing a first lignocellulosic material in the form of wood particles;  b) adding the first lignocellulosic material with a  A composition comprising at least one aminoplast resin and at least one first curing agent, wherein the first curing agent  hydrothermal and / or mechanical digestion of a second lignocellulosic material, and wherein the second lignocellulosic material is derived from a different raw material than the first lignocellulosic material;  c) pressing to a wood chip material. 2. The method according to claim 1, characterized in that during the  hydrothermal and / or mechanical digestion of at least one acid from the second lignocellulose-containing material is released. 3. The method according to claim 2, characterized in that the acid for  Hardening of the aminoplast resin contributes. 4. The method according to claim 2 or 3, characterized in that the acid has a molecular weight of 40 g / mol to 500 g / mol, in particular 40 g / mol to 250 g / mol. 5. The method according to any one of claims 2 to 4, characterized in that the Acid is a Brönsted acid having a pK _{a of} from 2 to 8, especially from 3 to 6. 6. The method according to any one of claims 2 to 5, characterized in that the acid is a carboxylic acid, in particular selected from the group consisting of formic acid, acetic acid, propionic acid, butanoic acid, pentanoic acid and derivatives thereof. 7. The method according to any one of the preceding claims, characterized in that the hydrothermal and / or mechanical pulping of the second lignocellulose-containing material at a temperature of 120 to 180 ° C, in particular at 140 to 160 ° C. 8. The method according to any one of the preceding claims, characterized in that the hydrothermal and / or mechanical pulping of the second lignocellulose-containing material at a pressure of 3 to 10 bar, in particular at 4 to 8 bar, takes place. 9. The method according to any one of the preceding claims, characterized in that the duration of the hydrothermal and / or mechanical digestion 2 seconds to 40 minutes, in particular 5 seconds to 30 minutes. 10. The method according to any one of the preceding claims, characterized in that the hydrothermal and / or mechanical pulping in a  Vorwärmbehälter, digester and / or refiner takes place. 11. The method according to any one of the preceding claims, characterized  in that the composition contains 0.1 to 15% by weight of the first hardener, in particular 0.5 to 10% by weight, in each case based on the solid resin content of the aminoplast resin. 12. A method for producing a wood chip material according to one of  preceding claims, wherein the hydrothermal and / or mechanical digestion indicated in step b) comprises the following steps: (i) hydrothermal digestion of the second lignocellulosic material in a digester and / or pressure reactor; (ii) mechanical digestion by comminuting the second lignocellulosic material of step (i) in a refiner. 13. The method according to any one of the preceding claims, characterized in that the wood particles in step a) are selected from the group consisting of finely divided wood material, wood flakes, wood wafers, wood strands, wood chips and wood chips. 14. The method according to any one of the preceding claims, characterized in that the second lignocellulosic material is selected from the group consisting of annuals, crops, grasses, foliage, cereals, their components, waste and mixtures thereof. 15. The method according to claim 14, characterized in that the crop is selected from the group consisting of straw, wheat, rye, barley, oats, millet, corn, miscanthus, rice, their components, waste and  Mixtures thereof. 16. The method according to any one of the preceding claims, characterized  characterized in that the aminoplast resin is a melamine or urea resin. 17. The method according to any one of the preceding claims, characterized  characterized in that the composition comprises a second hardener. 18. The method according to claim 17, characterized in that the second hardener is an ammonium salt, in particular selected from the group consisting of ammonium nitrate, ammonium chloride and ammonium sulfate. 19. The method according to claim 17 or 18, characterized in that the Composition 0.1 to 4 wt .-% of the second hardener, in particular 0.5 to 3.0 wt .-%, each based on the solid resin content of the aminoplast resin comprises. 20. The method according to any one of the preceding claims, characterized in that the wood chip material is a chipboard or an OSB board. 21. wood chip material, obtainable by a process according to any one of claims I to 20. 22. Use of a wood chip material according to claim 1 to 21 for the production of a laminate, floor covering, furniture, countertop, table top or pallet. 23. Use of a hydrothermally and / or mechanically digested  A lignocellulosic material as a curing agent for an aminoplast resin in a process for producing a wood chip material according to any one of claims 1 to 20.