JP2008531800A - Manufacture of compacts made of fine granular materials based on lignocellulose - Google Patents

Abstract

  The present invention relates to a method for producing a molded article made of a finely divided material based on lignocellulose and a molded article obtained thereby. Furthermore, the present invention relates to the use of said aqueous composition for the production of a microparticulate material treated with an aqueous composition containing at least one crosslinkable urea compound for the production of shaped bodies.

Description

  The present invention relates to a method for producing a molded article made of a finely divided material based on lignocellulose and a molded article obtained thereby. The invention further relates to the use of said aqueous composition for the production of a microparticulate material treated with an aqueous composition containing at least one crosslinkable urea compound for the production of shaped bodies.

  Molded bodies based on lignocellulose-based microparticulate materials (hereinafter also molded bodies based on lignocellulose particles), for example those based on wood particles, are used as building materials in the field of construction and furniture. Widely used. In general, their production is carried out by adhesive application (Beleimen) of lignocellulose particles and a liquid, usually aqueous composition of binder polymer, shaping and curing of the adhesive-coated material. Upon curing, adhesive bonding of the particulate material occurs, optionally under crosslinking of the binder, thereby obtaining the stability of the shaped body. In the case of wood plastic composites (Wood-Plastic-Composites = WPC), the particulate material is embedded in a plastic matrix. An overview of conventional shaped molds based on lignocellulose particles and methods for their production can be found in H. Ullmann's Encyclopedia of Industrial Chemistry, 5th edition, CD-ROM, Wiley-VCH, Weinheim 1997. H. Nimz et al., “Wood-Wood-based Materials”. As a mass-produced product, a molded body based on fine lignocellulose particles is under enormous cost pressure.

  A central problem in shaped bodies based on lignocellulose particles is their often only moderate to low water resistance. This results from the nature of lignocellulosic particles which, for example, incorporate water into the cell wall in contact with water or in a humid atmosphere. This causes the compacts to swell and their mechanical strength to decrease. In addition, shaped bodies based on lignocellulose particles are damaged by wood-degrading or discoloring bacteria, in particular microorganisms, especially in the wet state, so that the shaped bodies can be treated with corresponding fungicides and insecticides. Indispensable. This, on the other hand, creates subtle cost factors and is also an environmental disadvantage.

  For improved durability, wood and corresponding lignocellulose-based materials are frequently water repellent treated by treatment with a dipping agent containing, for example, wax. This makes it difficult for water to penetrate into the pores of the material.

  It has been proposed to improve the dimensional stability of wood materials such as particle boards and fiber boards and their stability against wood decay fungi by acetylation of wood particles with anhydrides such as acetic anhydride (EP- A213252 and references cited therein and Rowell et al., Wood and Fiber Science, 21 (1), pp. 67-79). Disadvantages are the high cost of processing and the unpleasant singular odor of the material so treated, so that these treatments have not become established in the market.

  Other chemicals such as isocyanates, siloxanes and acrylamides have also been proposed for the modification of lignocellulose fibers (J. Appl. Polym. Sci., 73 (1999) 2493-2505). However, these actions as a whole cannot meet the requirements

  WO 2004/033170 and WO 2004/033171 describe hydroxymethyl-modified urea derivatives or alkoxymethyl-modified urea derivatives such as 1,3-bis (hydroxy) for improving the durability, dimensional stability and surface hardening of wood from solid wood. Methyl) -4,5-dihydroxyimidazolidin-2-one, bis (hydroxymethyl) -4,5-dihydroxyimidazolidinone modified with alcohol, 1,3-bis (dihydroxymethyl) urea, 1,3- Bis (methoxymethyl) urea, 1-hydroxymethyl-3-methylurea, 1,3-bis (hydroxymethyl) imidazolidin-2-one, 1,3-dimethyl-4,5-dihydroxyimidazolidin-2-one Or based on tetra (hydroxymethyl) acetylene diurea It describes the use of the infusion. There is no mention of the problem of dimensional stability of molded bodies based on finely divided lignocellulose materials.

  Accordingly, the problem underlying the present invention is to provide a lignocellulose-based microparticulate material that can be produced under the wet action of shaped bodies having improved dimensional stability. Furthermore, the particulate material should be economical to manufacture in view of its use in the manufacture of mass-produced products such as fiberboard and particleboard.

Surprisingly, it has been found that this and other problems can be solved by a lignocellulose-based particulate material treated with an aqueous composition comprising at least one crosslinkable urea compound, in that case, the crosslinkable urea compound, (wherein, R is hydrogen or _C 1 -C ₄ alkyl as) the formula _CH 2 oR crosslinking at least one N- linked group, and / or two nitrogen atoms of urea Urea compound H having 1,2-bishydroxyethane-1,2-diyl group, initial condensate of urea compound H, urea compound H, C ₁ -C ₆ alkanol, C ₂ -C ₆ polyol and oligo Selected from reaction products or mixtures with at least one alcohol selected from among ethylene glycol.

  In the following, the finely divided material based on lignocellulose is also briefly described as finely divided lignocellulose material or lignocellulose particles. Accordingly, the microparticulate material based on lignocellulose treated according to the invention is also described as treated or microparticulate lignocellulose material according to the invention or treated or lignocellulose particles according to the invention, and Untreated lignocellulose-based microparticulate material is also described as untreated microparticulate lignocellulose material or untreated lignocellulose particles.

  Treatment is understood as impregnation or immersion of an untreated finely divided lignocellulosic material in an aqueous composition and optionally drying and / or curing of the impregnated material or the curable component absorbed by the impregnated material. Is done.

  A finely divided lignocellulosic material impregnated with an aqueous composition of a crosslinkable urea compound and treated so that the urea compound is crosslinked (cured) exhibits excellent mechanical properties, in particular during normal subsequent processing. To provide a shaped body characterized by improved shape stability or dimensional stability, that is, a relatively slight swelling upon contact with moisture, and a relatively high surface hardening. In addition, the shaped bodies are not significantly damaged by wood decaying microorganisms, such as harmful wood decay fungi and wood decaying bacteria, thereby reducing the cost of the corresponding fungicides and insecticides and even avoiding them frequently. Can be done. In so doing, the crosslinking of the crosslinkable urea compound of the aqueous composition is carried out by means of an adhesive with an ordinary binder for the production of shaped bodies, following impregnation, at an elevated temperature in a selectively independent drying / curing process. In the subsequent shape imparting method by coating, this is sometimes performed by adding a catalyst for promoting the curing of the urea compound.

Accordingly, the first subject of the present invention is at least one N-linked group of the formula CH ₂ OR, wherein R is hydrogen or C ₁ -C ₄ alkyl, and / or two of urea Urea compound H having 1,2-bishydroxyethane-1,2-diyl group bridging the nitrogen atom, initial condensate of urea compound H, urea compound H, C ₁ -C ₆ alkanol, C ₂ -C Based on lignocellulose treated with an aqueous composition containing at least one crosslinkable urea compound from the group of reaction products or mixtures with at least one alcohol selected from ₆ polyols and oligoethylene glycols The use of the aqueous composition for producing a finely divided material for producing a molded body.

  Furthermore, the invention relates to the treated lignocellulosic materials thus obtained and their use for the production of shaped bodies. The invention further relates to a shaped body produced using the use of this type of impregnated lignocellulosic material.

Aqueous compositions of the class of crosslinkable urea compounds of interest can be found, for example, from WO 2004/033170 and WO 2004/033171, cited at the outset, and Ullmann's Encyclopedia of Industrial Chemistry, 5th edition, CD-ROM edition, Wiley- VCH, K. in Weinheim 1997. Fisher et al., “Textile Auxiliaries-Finishing Agents”, chapter 7.2.2 and references cited therein, for example US Pat. No. 2,731,364 and US Pat. No. 2,930,715, and usually crosslinking for textile processing. Used as an agent. Reaction products of urea compounds with alcohols, such as modified 1,3-bis (hydroxymethyl) -4,5-dihydroxyimidazolidinone-2 (mDMDHEU) are known, for example from US 4,396,391 and WO 98/29393. is there. Otherwise, urea compounds H and their reaction products and precondensates are commercially obtained, for example, obtained from the BASF Aktiengesellschaft trade name Fixapret ^(R) CP and Fixapret ^(R) ECO.

  The urea compounds contained in the aqueous composition are low molecular weight compounds or oligomers having a relatively low molecular weight, which are generally present completely dissolved in water. Usually, the molecular weight of urea compounds is below 400 Daltons. It is envisaged that the compounds can be incorporated into the cell walls of lignocellulose particles based on these properties and improve the mechanical stability of the cell walls upon hardening and reduce their swelling caused by water. is there.

Examples for the crosslinkable urea compounds of the curable aqueous composition are the following but should not be limited to them:
-1,3-bis (hydroxymethyl) -4,5-dihydroxyimidazolidin-2-one (DMDHEU),
-C ₁ -C _{6 alkanols,} C 2 -C ₆ polyols, have been modified with oligoethylene glycol 1,3-bis (hydroxymethyl) -4,5-dihydroxy-2-one (modified DMDHEU or MDMDHEU) ,
-1,3-bis (hydroxymethyl) urea,
-1,3-bis (methoxymethyl) urea,
-1-hydroxymethyl-3-methylurea,
-1,3-bis (hydroxymethyl) imidazolidin-2-one (dimethylolethyleneurea),
-1,3-bis (hydroxymethyl) -1,3-hexahydropyrimidin-2-one (dimethylolpropylene urea),
-1,3-bis (methoxymethyl) -4,5-dihydroxyimidazolidin-2-one (DMeDHEU) and -tetra (hydroxymethyl) acetylene urea.

In one advantageous embodiment of the invention, the crosslinkable urea compound comprises 1,3-bis (hydroxymethyl) -4,5-dihydroxyimidazolidin-2-one and C ₁ -C ₆ alkanol, C ₂ -C _6. Selected among 1,3-bis (hydroxymethyl) -4,5-dihydroxyimidazolidin-2-one modified with polyol, oligoethylene glycol.

mDMDHEU is 1,3-bis reaction between (hydroxymethyl) -4,5-dihydroxy-imidazolidinone -2 and _C 1 -C _{6 alkanols,} C 2 -C ₆ polyols, oligoethylene glycol or mixtures of these alcohols Product. Suitable _C 1 -C ₆ alkanol, such as methanol, ethanol, n- propanol, iso - propanol, a n- butanol and n- pentanol, Preference is methanol. Suitable polyols are ethylene glycol, diethylene glycol, 1,2-propylene glycol and 1,3-propylene glycol, 1,2-butylene glycol, 1,3-butylene glycol and 1,4-butylene glycol, glycerin. Suitable oligoethylene glycols are especially those of the formula HO (CH ₂ CH ₂ O) _n having n of 2 to 20, among which diethylene glycol and triethylene glycol are preferred. For the production of mDMDHEU, DMDHEU is mixed with an alkanol, polyol or polyethylene glycol. In this case, monohydric alcohols, polyols or oligo- or polyethylene glycols are usually used in a ratio of 0.1 to 2.0, in particular 0.2 to 2, molar equivalents to DMDHEU. The mixture from DMDHEU, polyol or polyethylene glycol is usually reacted in water, preferably at a temperature of 20 to 70 ° C. and preferably at a pH value of 1 to 2.5, with the pH value generally being the reaction Later, it is set in the range of 4-8.

The curable aqueous composition, in addition to or wherein the alcohol of the reaction products or precondensates of the urea compound H or the compound (component A), C ₁ ~C ₆ alkanols, C ₂ -C ₆ polyols, oligoethylene glycol One or more or a mixture of these alcohols may also be included (component C). Suitable _C 1 -C ₆ alkanol, such as methanol, ethanol, n- propanol, iso - propanol, a n- butanol and n- pentanol, Preference is methanol. Suitable polyols are ethylene glycol, diethylene glycol, 1,2-propylene glycol and 1,3-propylene glycol, 1,2-butylene glycol, 1,3-butylene glycol, and 1,4-butylene glycol, glycerin. Suitable oligoethylene glycols are especially those of the formula HO (CH ₂ CH ₂ O) _n having n of 2 to 20, among which diethylene glycol and triethylene glycol are preferred.

  The concentration of the urea compound H or its reaction product or initial condensate in the aqueous composition is usually in the range of 1 to 60% by mass, frequently in the range of 10 to 60% by mass, based on the total mass of the composition. And in particular in the range from 15 to 50% by weight. When the curable aqueous composition contains one of the alcohols, its concentration is preferably in the range from 1 to 50% by weight, in particular in the range from 5 to 40% by weight. The total amount of component A) and component C) usually amounts to 10 to 60% by weight and in particular 20 to 50% by weight of the total weight of the aqueous composition.

  In addition to components A) and optionally C), the aqueous composition may also contain a catalyst K that causes the crosslinking of urea compound H or its reaction products or precondensates. In general, as catalyst K, metal halides, metal sulfates, metal nitrates, metal phosphates, metal salts from the group of metal tetrafluoroborate; boron trifluoride; ammonium halide, ammonium sulfate, ammonium oxalate and Ammonium salts from the group of diammonium phosphates; and organic carboxylic acids, organic sulfonic acids, boric acid, sulfuric acid and hydrochloric acid are suitable.

  Examples for metal salts suitable as catalyst K are in particular magnesium chloride, magnesium sulfate, zinc chloride, lithium chloride, lithium bromide, aluminum chloride, aluminum sulfate, zinc nitrate and sodium tetrafluoroborate.

  Examples for ammonium salts suitable as catalyst K are in particular ammonium chloride, ammonium sulfate, ammonium oxalate and diammonium phosphate.

  As catalysts K, in particular water-soluble organic carboxylic acids such as maleic acid, formic acid, citric acid, tartaric acid and oxalic acid, as well as benzenesulfonic acid, p-toluenesulfonic acid, but also inorganic acids such as hydrochloric acid, sulfuric acid, boron Acids or mixtures thereof are also suitable.

  The catalyst K is preferably selected from magnesium chloride, zinc chloride, magnesium sulfate, aluminum sulfate or mixtures thereof, with magnesium chloride being particularly advantageous.

  Normally, catalyst K is added to the aqueous composition only shortly before impregnation of the lignocellulosic material. Usually it is used in an amount of 1 to 20% by weight, in particular 2 to 10% by weight, based on the total weight of component A) and optionally C) contained in the curable aqueous composition. Usually, the concentration of the catalyst is in the range of 0.1 to 10% by mass and in the range of 0.5 to 5% by mass with respect to the total mass of the curable aqueous composition.

  Moreover, the aqueous composition used for impregnation may contain some or all of the binder necessary for the production of the molded body, which binder will be described in further detail below. If desired, the concentration of the binder in the aqueous composition is usually in the range from 0.5 to 25% by weight, frequently in the range from 1 to 20% by weight and in particular from 5 to 15%, based on the total weight of the aqueous composition. It is in the range of% by weight and is calculated as dry glue components (i.e. does not include any solvent or diluent components of the binder that may occur).

  The binder component of the adhesive composition, unlike the crosslinkable urea compound, catalyst K and optionally present component C) alcohol, is not absorbed by the cell walls of the lignocellulose particles or only to a small extent, the particles It is envisaged that most remains on the surface of the resin and can therefore be used as a binder in the shaping process of the subsequent production of shaped bodies.

  In principle, the production of a finely divided material based on lignocellulose impregnated with an aqueous composition is carried out in two different ways.

  Therefore, according to a first embodiment of the present invention, a coarsely granulated raw material based on lignocellulose, such as a wood block, is described in WO 2004/033170 or WO 2004033171 with an aqueous composition containing catalyst K. Treatments that may be processed in the process followed by pulverization, for example by shredding, loosening into fibers or by grinding, or processing that occurs upon processing or recycling of the material thus obtained Timber waste or wood fiber can be obtained.

  However, advantageously, the untreated finely divided material based on lignocellulose is impregnated with the curable aqueous composition and the catalyst K, followed by crosslinking of the urea compounds contained in the composition and thus curing of the composition. Subject to conditions that cause The aqueous composition and catalyst K are applied to the untreated finely divided material based on lignocellulose, either together in one composition or in two separate compositions. Usually, however, the catalyst K is incorporated into the aqueous composition prior to application. However, a first aqueous formulation containing a finely divided material based on lignocellulose in the form of dissolved catalyst K, and a second aqueous composition containing a crosslinkable urea compound and optionally an alcohol component C) It is also conceivable to impregnate with the material simultaneously or successively.

  The type of untreated finely divided lignocellulosic material depends on the shaped body to be produced in a known manner. Examples for suitable finely divided lignocellulosic materials include, but are not limited to, wood, such as wood waste, such as shredded logs and logs, shredded industrial wood and industrial residual wood, Sawdust and plywood waste, scraps of wood digested by thermomechanical treatment, citrus and peel scraps, wood chips and pieces, and raw materials containing lignocelluloses of different wood, such as bamboo, bagasse , Cotton stalk, jute, sisal, cocoon, flax, coconut fiber, banana fiber, reed such as Susuki, ramie, hemp, Manila hemp, esparto (alphagrass), rice husk and cork.

  In this case, the untreated finely divided lignocellulosic material may be present in the form of granules, fines, or preferably waste, including sawdust and knots, fibers and / or pieces. Of these, materials from wood and bamboo, such as wood fiber, wood waste, wood chips and wood pieces or bamboo fiber, bamboo pieces and bamboo waste and mixtures thereof are particularly advantageous. In particular, it is a finely divided material from wood. The types of wood that make up the particulate material are, for example, conifers such as pine, spruce, pine, larch, pine, fir, cedar, European pine, and broadleaf, such as maple, acacia, birch, beech, oak, alder, ash, These include: porcupine, hazel, beartail, cherry, lime, poplar, harienge, elm, walnut tree, willow, turkey oak, etc.

  The size, ie the dimensions (length, thickness), of at least 90% of the finely divided lignocellulosic material is usually in the range from 0.1 to 20 mm, in particular from 0.5 to 10 mm and in particular from 1 to 5 mm, On the other hand, in the case of a microparticulate material formed into a square having a length / width ratio> 5, the length of at least 90% of the particles may also be greater than 10 mm and up to 200 mm. The average width or thickness of the rectangular particles is typically in the range from 0.1 to 10 mm, in particular in the range from 0.2 to 5 mm and in particular in the range from 0.3 to 3 mm.

  The impregnation or dipping of the untreated finely divided material based on lignocellulose can be carried out, for example, by dipping the fibers in an aqueous composition, by applying a vacuum, optionally in combination with pressure, or by spraying. In general, the conditions are selected such that the absorbed amount of the curable component of the aqueous composition is at least 1% by weight relative to the dry matter of the raw material. The absorbed amount of curable component may be up to 100% by weight relative to the dry matter of the untreated lignocellulosic material and is frequently 1-60% with respect to the dry matter of the raw material used. %, Preferably in the range 5-50% by weight and in particular in the range 10-30% by weight. Usually, the impregnation is performed at ambient temperature, typically in the range of 15-40 ° C.

  The moisture of the untreated lignocellulosic material used for soaking is not critical and may be up to 100%, for example. Here and hereinafter, the concept of “moisture” is synonymous with the concept of residual moisture content according to DIN 52183. Frequently it is in the range of 1-80% and especially 5-50%.

  Upon soaking, untreated finely divided lignocellulosic material, preferably having a moisture content in the range from 1 to 100%, is applied in the aqueous composition in the container over a period of several seconds to 12 hours, in particular 1 minute to 60 minutes. Soaked in or suspended therein. In this case, the finely divided lignocellulosic material has an aqueous impregnated composition, wherein the finely divided lignocellulosic material depends on the concentration of the curable components (ie components A) and C)) in the aqueous composition, depending on the temperature and processing time. The amount of curable component absorbed by the lignocellulosic material can be controlled. The amount of curable component actually absorbed can be calculated via the mass increase of the finely divided lignocellulosic material and the concentration of the aqueous composition in an easy manner by those skilled in the art.

  Impregnation can also be achieved by the application of reduced pressure, optionally followed by a step with increased pressure. For this purpose, finely divided lignocellulosic materials under reduced pressure, frequently in the range from 10 to 500 mbar and in particular in the range from 50 to 100 mbar, are immersed in the aqueous composition, for example in the curable aqueous composition or It is made to react by making it suspend. The length of time is usually in the range of 1 minute to 1 hour. Optionally, steps may be followed at elevated pressure, for example in the range of 1 bar to 20 bar. The duration of this stage is usually in the range from 1 minute to 6 hours, in particular from 5 minutes to 1 hour. In this case, the finely divided lignocellulosic material has an aqueous impregnation composition, wherein the finely divided lignocellulosic material depends on the concentration of the curable component in the aqueous composition, on the applied pressure, on the temperature and on the processing time. The amount of curable component absorbed by can be controlled. The amount actually absorbed can again be calculated via the mass increase of the finely divided lignocellulosic material.

  In yet another embodiment of the present invention, the impregnation is performed by spraying untreated lignocellulose particles with an aqueous composition. Advantageously, the lignocellulose particles have a moisture content of not more than 50%, for example in the range from 1% to 30%. Spraying is usually performed at a temperature in the range of 15-50 ° C. Depending on the concentration of the curable component in the aqueous composition, the amount applied can be controlled by the amount applied, by temperature and by the time of spraying, by the amount of curable component absorbed by the particulate lignocellulosic material. The amount of curable component actually absorbed results directly from the amount of aqueous composition sprayed. Spraying may be carried out in the usual manner in all devices suitable for solid spraying, for example in spray towers, fluidized bed devices and the like.

  The impregnation may be performed using ultrasonic waves.

  The impregnated fine lignocellulose particles thus obtained are optionally formed into a shaped body by subsequent processing by a drying and / or curing step.

  In most cases, subsequent processing involves the adhesive application of the raw particulate material with a blend of liquid or powdered binder, and the shaping and curing of the adhesive-coated material to form a compact. Is included. In other cases, for example in the production of WPC's, the subsequent processing involves mixing the material obtained in step i) with the thermoplastic polymer and shaping the mixture. In this case, the production in step i) usually comprises an impregnation step and a drying or curing step.

Therefore, the present invention also relates to a method for producing a molded body comprising a finely divided material based on lignocellulose, the production method comprising:
i) preparation of a microparticulate material based on lignocellulose impregnated and optionally cured with the curable aqueous composition described herein;
ii) Adhesive application of the lignocellulose-based microparticulate material obtained in step i) or a mixture of it with other microparticulate materials and a blend of liquid or powdered binders; and iii) shaped bodies Shaping and curing an adhesive-coated microparticulate material,
Or ii ′) mixing of the treated, preferably dried and / or hardened lignocellulose-based fine particulate material obtained in step i) with a thermoplastic polymer and iii ′) shaped bodies To give the mixture a shape.

  Furthermore, this invention relates to the molded object obtained by this method.

  If the preparation of the treated finely divided lignocellulosic material involves impregnation of untreated lignocellulosic material, following the impregnation in step i) and prior to the adhesive application in step ii), a drying step, also below A pre-drying step may also be performed. In this case, the volatile components of the aqueous composition that do not react in the curing / crosslinking of the urea compound, in particular water and excess organic solvent, are partially or completely removed. In addition, depending on the drying temperature selected, partial or complete curing / crosslinking of the curable components contained in the composition may be performed. The pre-drying / curing of the impregnated material is usually carried out at a temperature of 50 ° C. to 220 ° C., in particular in the range of 80 to 200 ° C. If curing is desired, drying is advantageously carried out above 100 ° C. Curing / drying can be carried out in a conventional fresh air / exhaust air system, for example in a rotary dryer. Advantageously, the pre-drying is carried out such that the moisture content of the finely divided lignocellulosic material is not more than 30%, in particular not more than 20%, relative to the dry matter after the pre-drying. It may be advantageous to run the drying / curing to a moisture content of <10% and in particular <5% with respect to the dry matter. The moisture content can be controlled in an easy manner by the temperature, time and pressure selected during pre-drying.

  However, a pre-drying step is not necessary in principle and the removal of the volatile components and the crosslinking of the curable components of the aqueous composition may also be carried out following the adhesive application in step ii) or the shaping step and curing It can be carried out in step iii). Such processing methods not only have the advantage of method simplification, but also allow for relatively short adhesive application and shape application times. Therefore, in one advantageous embodiment, advantageously a separate drying step is not carried out and the adhesive application is carried out immediately following or simultaneously with the impregnation.

  If the aqueous composition already contains an amount of binder sufficient to produce a molded body, processing step i) and adhesive application ii) overlap in time and removal of volatile components and curing of the aqueous composition Crosslinking of the sex component is performed in the shape imparting step and the curing step iii).

  If the aqueous composition used to impregnate in step i) does not contain an amount of binder sufficient to produce a shaped body, the impregnated and optionally pre-dried and cured lignocellulose particles are Then, in the usual way, an adhesive is applied with the binder required to produce the shaped body.

  This adhesive application may be performed by a normal method. In some cases, further particulate materials, additives, catalysts or auxiliaries forming a shaped body are added at this stage.

The kind of binder follows the kind of the molded object which should be manufactured in a well-known method. Suitable binders are e.g. Pizzi (Hrsg.): Wood Adhesives, Marcel Dekker, New York 1983. Examples for binders are:
i) thermosetting binders (reactive binders), such as aminoplast resins, phenolic resins, isocyanate resins, epoxide resins and polycarboxylic acid resins;
ii) thermoplastic materials such as polyethylene, polypropylene, polystyrene resins, polysulfones, polyester resins; and iii) film-forming polymers such as styrene acrylate, polyacrylates (acrylate / methacrylate esters-copolymers), vinyl acetate-polymers (polyvinyl). Acetate), aqueous polymer dispersions based on styrene-butadiene copolymers and the like.

  Preferred binders are the thermosetting binders described in group i) and their mixtures with the film-forming polymers of group iii), wherein the thermosetting binder is preferably of an aqueous formulation Used in form.

  Preferred binders are aminoplast resins, phenolic resins, isocyanate resins, polyvinyl acetate and polycarboxylic acid resins.

Particularly suitable aminoplast resins are urea formaldehyde condensates (urea-formaldehyde condensates) and melamine formaldehyde condensates (melamine-formaldehyde condensates). They are commercially obtained under the name Kaurit as an aqueous solution or powder ^(R) and Kauramin ^(R) (manufacturer BASF), and urea - and / or melamine - formaldehyde - containing precondensate. Typical phenolic resins are phenol-formaldehyde condensates, phenol-resorcin-formaldehyde condensates and the like. Also suitable are mixed condensates of aminoplast resin and phenolic resin. Examples for mixed condensates of aminoplast resins and phenolic resins are urea-melamine-formaldehyde condensates, melamine-urea-formaldehyde-phenol condensates, and mixtures thereof. Their production and use for producing shaped bodies of finely divided lignocellulosic materials are generally known. Preference is given to urea-formaldehyde resins and in particular those having a molar ratio of 1 mol of urea to 1.1 to 1.4 mol of formaldehyde.

  During the processing of aminoplast and phenolic resins, conversion of soluble and fusible precondensates to insoluble and infusible products takes place. During this process, referred to as curing, as is known, consistent cross-linking of the initial condensate, which is generally accelerated by curing, occurs. Curing agents known to those skilled in the art for urea resins, phenolic resins and / or melamine-formaldehyde resins, such as acid-reactive compounds and / or acid-separating compounds, such as ammonium salts or amine salts, may be used as curing agents. . Generally, the hardening | curing agent ratio in an adhesive resin solution is 1-5 mass% with respect to a liquid resin ratio.

As the isocyanate resin, all usual resins based on methylenediphenylene isocyanate (MDI) are suitable. They generally consist of mixtures of monomers and oligomeric diisocyanates or polyisocyanates, so-called precondensates that can react with the moisture of cellulose, lignin and lignocellulose particles. Suitable isocyanate resins are, for example, commercially available under the trade ^Lupranat (R) (Elastogran Inc.).

Examples for reactive polycarboxylic acid resins are:
i) 5 to 100% by weight, preferably 5 to 50% by weight, of ethylenically unsaturated acid anhydride or ethylenically unsaturated dicarboxylic acid or alkanol in which the carboxylic acid group can form an anhydride group The product of its reaction with an amine (monomer a)) and a monomer b) different from monomer a) b) from ethylenically unsaturated monomers composed of 0 to 95% by weight, preferably 50 to 95% by weight Polymer P; and ii) at least one alkanolamine A- (OH) ₂ and / or alkoxylated polyamine having at least two hydroxyl groups and iii) optionally a water-insoluble, water-dispersible film-forming polymer P ′
It is a composition containing this.

  Reactive polycarboxylic acid resins are known to those skilled in the art and are described, for example, in EP-A-882093, WO 97/45461, WO 99/09100, WO 99/02591, WO 01/27163 and WO 01/27198.

  Particular preference is given to polymers P which contain maleic acid and / or maleic anhydride as monomer a).

Preferred polymers b) are ethylenically unsaturated C ₃ -C ₆ monocarboxylic acids such as acrylic acid, methacrylic acid, olefins such as ethene, propene, butene, isobutene, cyclopentene, diisobutene, vinyl aromatic compounds such as styrene, Alkyl vinyl ethers such as methyl vinyl ether, ethyl vinyl ether, acrylamide, 2-acrylamido-2-methylpropane sulfonic acid, vinyl acetate, butadiene, acrylonitrile or mixtures thereof. Particularly preferred monomers b) are acrylic acid, methacrylic acid, ethene, acrylamide, styrene and acrylonitrile or mixtures thereof.

Particular preference is given to polymers P in which the monomer b) comprises at least one C ₃ -C ₆ monocarboxylic acid, preferably acrylic acid, as comonomer b).

As component A- (OH) ₂ alkanolamines having at least two OH groups are used, for example diethanolamine, triethanolamine, diisopropanolamine, triisopropanolamine, methyldiethanolamine, butyldiethanolamine and methyldiisopropanolamine. . Preference is given to triethanolamine. In addition, component A- (OH) ₂ includes alkoxylated, in particular ethoxylated polyamines, such as those described in WO 97/45461, such as compounds of formula I and in particular Ia, Ie and If. It is.

  As component P 'and as binder of group iii), in principle, all polymers which are water-insoluble and which form a film and are dispersible in water are taken into account. This includes in particular emulsion polymers and powders made therefrom, for example referred to as polymer A1 in WO 01/27198. The polymer P 'frequently has a glass transition temperature in the range of -10 to + 150 ° C and in particular in the range of +20 to + 120 ° C. In particular, it is based on styrene / butadiene based copolymers based on styrene / alkyl acrylate and alkyl methacrylate / alkyl acrylate.

For the preparation of the polycarboxylic acid resin, advantageously, the polymer P and the alkanolamine A- (OH) ₂ have a molar ratio of carboxyl groups of component P to hydroxyl groups of component A- (OH) ₂ of 20: Used in a ratio of 1: 1 to 1, preferably 8: 1 to 5: 1 and very particularly preferably 5: 1 to 1.7: 1 (in this case the anhydride groups are Calculated as a base).

  Usually the binder is used in an amount of 0.5 to 30% by weight, frequently 1 to 20% by weight, in particular 5 to 15% by weight, based on the treated lignocellulosic material.

  The advantageous binders of group i) may also be used, of course, in mixtures with one another or in mixtures with binders of group ii) and in particular iii).

  Moreover, for the production of the shaped bodies, customary auxiliaries and admixtures may be used, for example the curing agents already mentioned above, ie catalysts which cause a faster crosslinking of the binder.

  Auxiliaries include, for example, fungicides or insecticides and water repellents to increase the water resistance of the molded body. Suitable water repellents are the usual aqueous paraffin dispersants or silicones. Furthermore, wetting agents, thickeners, plasticizers, and yield improvers may be used during production. These are frequently added to the binder composition. Frequently, the binder composition also contains a coupling reagent, such as an alkoxysilane, such as 3-aminopropyltriethoxysilane, a soluble or emulsifying oil and dust adsorbent as a lubricant, and a wetting aid.

  Common admixtures are inert fillers such as aluminum silicate, quartz, precipitated silica or pyrogenic silica, Leichtspat and barite, talc, dolomite or calcium carbonate; color imparting pigments such as titanium white , Zinc white, iron oxide black and the like.

  Finally, customary fireproofing agents such as aluminum silicate, aluminum hydroxide, borates and / or phosphates may be used in the production of the shaped bodies.

  Adhesive application is carried out according to the usual methods for this, for example by mixing the impregnated fine lignocellulosic material and the binder in a conventional mixing device for mixing liquid and solid materials. Fluidization of the lignocellulosic material in, and spraying of the binder, preferably in the form of a liquid binder composition, into the fiber stream so produced (blow-line method) "-Verfahren).

  The adhesive-coated mixture from the lignocellulose-containing material and the binder composition is pre-dried at an elevated temperature for removal of volatile components, eg, at a temperature of 10-200 ° C., prior to shaping. It's okay. However, removal of volatile components may be omitted depending on the type of binder composition, or may be pre-dried during the shape imparting step.

  Following the adhesive application and optionally pre-drying, generally at elevated temperatures in a manner known per se, for example at temperatures of 50 to 300 ° C., preferably 100 to 250 ° C. and particularly preferably 140 to 225 ° C. And a shaping step is carried out, which is usually carried out at an elevated pressure of generally 2 to 200 bar, preferably 5 to 100 bar, particularly preferably 20 to 50 bar.

  Suitable methods of shaping are known to those skilled in the art and include, for example, extrusion methods, deep drawing and in particular hot pressing, in which these methods are discontinuous or continuous, for example roller presses, It may be arranged as a slide press (Gleitpressen), calendar press, extrusion press, steam injection press. For an overview of conventional methods, see, for example, Ullmann's Encyclopedia of Industrial Chemistry, “Wood-Wood based Materials”, Chapters 2.3.1, 2.3.2, and 2.2.3. Edition, CD-ROM edition, Wiley-Verlag-Chemie, Weinheim 1997.

  At temperatures and pressures governing shape formation, the lignocellulosic particles are adhesively bonded, and depending on the type of binder, melting and / or cross-linking of the binder component occurs, thus providing a molded body that is stable upon cooling and removal of the mold. Arise.

  The shaped bodies can be arbitrarily shaped and have a planar shaped body, such as a board or mat, or a three-dimensional form, such as a specially shaped shaped member. Examples for planar shaped bodies are OSB boards (oriented structural boards), particle boards, wafer boards, insulation boards, medium density fiber boards (MDF) and high density fiber boards (HDF). ). The molded bodies according to the invention also include OSL boards and OSL molded parts (Oriented-Strand-Lumber), and PSL boards and PSL molded parts (Parallel-Strand-Lumber). It is. Molded bodies also include molded parts from WPC (wood plastic composite).

  The process according to the invention is particularly suitable for the production of shaped bodies in which the lignocellulosic material is wood. In this case, depending on the size of the lignocellulose-containing particles used, OSB (oriented structural board) board, particle board, wafer board, OSL board and OSL molded member (oriented strand lumbar), PSL board And PSL molded members (parallel strand lumber), insulation boards, medium density fiber boards (MDF), high density fiber boards (HDF), and the like.

  The method according to the invention is described, for example, in WO 96/34045, the literature cited therein and in general methods, Kunststoffzeitschrift 35, 2004, 10-13 and Klauditzforum 5th edition. As described in 6/2004, it is also particularly suitable for the production of so-called WPCs (wood plastic composites). Known methods for producing WPC can be carried out on lignocellulosic materials treated according to the invention in a similar manner.

For the production of WPC's, the finely divided lignocellulosic material treated according to the invention is first subjected to a drying / curing step and then to at least one thermoplastic material such as polyethylene, polypropylene, etc. -C ₂ -C ₆ olefin-based, or polyvinyl chloride, poly -C ₂ -C ₄ thermoplastic polymer based on halogen-olefins or vinyl chloride and vinylidene chloride, such as polyvinylidene chloride, polyvinyl acetate and / Or mixed with a copolymer of C _{2 to} C ₆ olefins and subsequently subjected to a shaping process, generally an injection molding or extrusion process. In that case, the thermoplastic polymer is generally 20 to 90% by weight and in particular 30 to 80% by weight, based on the total amount of substances. Accordingly, the proportion of the finely divided lignocellulosic material treated according to the invention is in the range from 10 to 80% by weight and in particular from 20 to 70% by weight, based on the total weight of WPC's. In addition, conventional additives such as adhesion promoters (eg, organosilanes, maleic anhydride, isocyanates), pigments, light stabilizers, lubricants or flame retardant components may be added to WPC's. In contrast, the addition of insecticide is not necessary.

  The finely divided lignocellulosic materials treated according to the invention include wood particles, in particular wood materials such as HDF, MDF, OSB, OSL and PSL (see Ullmann's Encyclopedia of Industrial Chemistry, cited above). Suitable for the production of boards and wood fiber boards, which are achieved by adhesive application of divided wood, for example wood waste, wood pieces, wood chips and / or wood fibers.

  The manufacture of particle boards is generally known and is described, for example, in H.C. J. et al. Deppe, K.M. Described in Ernst Taschenbuch der Spanplattentechnik, 2nd edition, Leinfelden publisher 1982 and can be used in the method according to the invention as well.

  In the production of the particle board, the adhesive application of the previously dried waste is performed in a continuous mixer. In most cases, the various litter parts are variously glued in separate mixers and then deposited separately (multilayer board) or together. Preference is given to using scraps whose mean scrap thickness is on average 0.1 to 2 mm, in particular 0.2 to 0.5 mm and containing less than 6% by weight of water. The binder composition is applied onto the wood waste as uniformly as possible, for example by spraying the binder composition onto the waste wood in a finely divided form. The glued wood waste is subsequently sprinkled into a layer with as uniform a surface as possible, the thickness of the layer being in accordance with the desired thickness of the finished particle board. The sprayed layer is optionally cooled and pre-compressed and compression-molded into a board according to dimensions by application of a pressure of usually 10 to 750 bar, for example at a temperature of 100 to 250 ° C., preferably 140 to 225 ° C. The required compression time may vary further and is generally between 15 seconds and 30 minutes.

  The appropriate quality wood fibers required for the production of medium density wood fiber boards (MDF) are ground from bark-free wood pieces at a temperature of about 180 ° C. in a special grinder or so-called refiner. Can be manufactured.

  In manufacturing MDF and HDF boards, the fibers are adhesively applied in a blow line by a refiner. For adhesive application, wood fibers are generally fluidized by a stream of air and a binder composition is sprayed into the fiber stream so produced (“blow line” method). The adhesive coated fiber then passes through a dryer where it is dried to 1-20% by weight moisture. In some cases, the fibers are also first dried and then glued in a special continuous mixer. A combination of blow line and adhesive application with a mixer is also possible. The ratio of wood fiber to binder composition to dry matter content or solid content is usually 40: 1 to 3: 1, preferably 20: 1 to 4: 1. The adhesive-coated fibers are dried in a fiber stream, for example at a temperature of 130-180 ° C., spread onto a fiber fleece, optionally cooled and pre-compressed, and board or molded at a pressure of 20-40 bar. It is compression molded into the body.

  During OSB production, the wood chips (strands) are optionally adhesively applied after drying separately in the intermediate layer material and the coating layer material and separately in a continuous mixer. For board finishing, the glued wood waste is then deposited on a mat, optionally cooled and pre-compressed, and into a board at a temperature of 170-240 ° C. in a heated compressor. It is compression molded.

  Wood fibers coated with adhesive as described in DE-OS 2417243 can also be processed into a portable fiber mat. This semi-finished product can then be further processed in a second, temporally and spatially separated process to obtain a board or molded part, for example an automobile interior door trim.

  Other lignocellulosic materials such as natural fiber materials such as sisal, jute, hemp, ramie, cocoon, flax, coconut fiber, banana fiber and other natural fibers are also processed into boards and molded bodies using known binders. Can be done. Natural fiber materials can also be used in mixtures with plastic fibers such as polypropylene, polyethylene, polyester, polyamide or polyacrylonitrile. In so doing, these plastic fibers can also act as co-binders in addition to the binder compositions mentioned above. The proportion of plastic fibers is then preferably less than 50% by weight, in particular less than 30% by weight and very particularly preferably less than 10% by weight, based on all waste, pieces or fibers. The processing of the fibers can be carried out according to the method implemented in the case of wood fiber boards. However, it is also possible to impregnate a pre-shaped natural fiber mat with the binder according to the invention, optionally with the addition of a wetting aid. The impregnated mat is then compression molded into a board or molded member, for example at a temperature of 100-250 ° C. and a pressure of 10-100 bar, with the binder wet or pre-dried.

  Due to its high stability, the shaped bodies according to the invention are used as a basis for structural members in houses and ships, for example, for many different applications, in particular for applications that are exposed to weathering and humidity. For example, for interior and exterior walls, floor construction, for the coating of houses, ships and automobile structures, for example as exterior, interior, trunk room and engine room lining, decorative panels, such as ceiling panels, wall panels and ready-made Suitable as a support for parquet floor panels, as a member and board in the furniture industry and for household tool areas and the like.

  The following examples are merely illustrative of the examples according to the present invention and should not be understood as limiting.

  The stated moisture content was measured according to DIN 52183.

Example 1:
As impregnating agent, a 50% aqueous solution of DMDHEUs (mDMDHEU) modified with diethylene glycol and methanol was used, and the solution was mixed with 1.5% MgCl ₂ × 6H ₂ O.

  Spruce wood scraps digested by thermomechanical treatment with an average fiber length (90% value) and a moisture content of 11% were introduced into a dipping device using a metal basket. The immersion device was subjected to a vacuum of 100 mbar (absolute) for 30 minutes and subsequently fluidized with the impregnating agent. Subsequently, a pressure of 10 bar was applied for 1 hour. The pressure phase was terminated and residual liquid was removed. Subsequently, the waste so obtained was dried in a dryer for 4 hours at 50 ° C.

Example 2:
In the same manner as in Example 1, all the pine wood having an average dimension of 0.5 mm × 5 mm × 100 mm was dipped and subsequently dried.

Example 3:
The impregnated pinewood litter obtained in Example 2 was heated to 130 ° C. in a drying oven for 1 hour to obtain a cured pinewood litter.

Example 4: Preparation of particleboard 5400 g of dried waste from Example 1 was sprayed with 1628 g of the composition described in Table 1, of which 3370 g was poured into a mold (56.5 cm x 44 cm). The material was compressed in a press at 190 ° C. to a thickness of 18 mm in 230 seconds to make a particle board.

  The particle board contained 14% solid resin / atro waste and 0.5% solid wax / atro waste (atro = mass% based on dry waste).

Table 1
Urea-formaldehyde resin, 68% 100.0T
Paraffin-emulsion, 60% 6.3T
Ammonium nitrate solution, 52% 4.0T
T = part by mass

Example 5: Production of MDF board 1000gatro fibers from Example 3 were sprayed with the adhesive batch described in Table 2 and dried to 8% moisture. Among them, 920 g was poured into a mold (30 cm × 30 cm). The material was compressed in a press at 190 ° C. to a thickness of 12 mm in 300 seconds to make an MDF board.

  The MDF board contained 14% solid resin / atro fiber and 0.5% solid wax / atro fiber.

Table 2:
Urea-formaldehyde resin, 68% 100.0 g
Paraffin-emulsion, 60% 3.2 g
11.8 g of water

Example 6:
In each case 70 g of wood fibers from Example 3 were mixed well with 13.2 g of a powdered composition according to Examples P2 to P6 of WO 01/27198. Subsequently, 14 g of water was further sprayed onto the fiber-binder mixture while mixing was continued. The adhesive coated fibers were dried and sprinkled at 70 ° C. to a residual moisture of 10% atro to make a 19 × 19 cm fiber mat.

  These fiber mats are compression molded between two metal boards with a 2 mm spacer for 120 seconds at a pressing temperature of 220 ° C. by means of a hydraulic press (manufacturer Wickert Maschinenbau GmbH, Landau, WKP600 / 3, 5/3 model). did. For this purpose, a pressing pressure of 50 bar was first set for 20 seconds. The pressure of 200 bar was then maintained for a further 90 seconds after the pressure release continued for 10 seconds.

  The resulting fiberboard was stored in standard atmosphere for 24 hours at 23 ° C. and 65% relative humidity and subsequently tested. The water absorption was measured via mass increase (described as a percentage of the original mass). The thickness swelling of the wood fiber board was measured in the same way as DIN 52351 in demineralized water after storage for 24 hours as a relative increase in specimens measuring 2 × 2 cm.

Example 7
As in Example 2, waste wood produced by cutting a DMDHEU-modified pine board made according to WO 2004/033170 was treated with the adhesive described in Example 3 as in Example 4 and 190 A particle board (density 650 kg / m ³ ) was made by compression molding at 230 ° C. for 230 seconds. In parallel, a piece of pine wood that had not been modified was compression molded under the same conditions to produce a particleboard. The so produced particleboard was stored in water for 24 hours and swelling was measured as a relative increase in thickness.

Claims (25)

(Wherein, R is hydrogen or _C 1 -C ₄ alkyl as) the formula _CH 2 OR at least one N- linked group, and / or 1,2-bis-hydroxy ethane bridging two nitrogen atoms of the urea - Selected from urea compound H having 1,2-diyl group, initial condensate of urea compound H, and urea compound H, C ₁ -C ₆ alkanol, C ₂ -C ₆ polyol and oligoethylene glycol Fine granules for producing shaped bodies based on lignocellulose treated with an aqueous composition containing at least one crosslinkable urea compound selected from reaction products or mixtures with at least one alcohol Use of said aqueous composition for producing a material. The crosslinkable urea compound is -1,3-bis (hydroxymethyl) -4,5-dihydroxyimidazolidin-2-one;
1,3-bis (hydroxymethyl) -4,5-dihydroxyimidazolidin-2-one modified with C ₁ -C ₆ alkanol, C ₂ -C ₆ polyol, oligoethylene glycol or polyethylene glycol,
-1,3-bis (hydroxymethyl) urea,
-1,3-bis (methoxymethyl) urea,
-1-hydroxymethyl-3-methylurea,
-1,3-bis (hydroxymethyl) imidazolidin-2-one,
-1,3-bis (hydroxymethyl) -1,3-hexahydropyrimidin-2-one,
-1,3-bis (methoxymethyl) -4,5-dihydroxyimidazolidin-2-one,
Use according to claim 1, wherein the use is selected among tetra (hydroxymethyl) acetylene diurea. Crosslinkable urea compound modified with 1,3-bis (hydroxymethyl) -4,5-dihydroxyimidazolidin-2-one or C ₁ -C ₆ alkanol, C ₂ -C ₆ polyol, oligoethylene glycol or polyethylene glycol The use according to claim 2, which is made 1,3-bis (hydroxymethyl) -4,5-dihydroxyimidazolidin-2-one.   The use according to any one of claims 1 to 3, wherein the concentration of the crosslinkable urea compound in the aqueous curable composition is in the range of 1 to 60% by mass relative to the total mass of the composition.   Use according to any one of claims 1 to 4, wherein the aqueous composition contains at least one catalyst K which causes crosslinking of the urea compound.   Catalyst K is a metal salt from the group of metal halide, metal sulfate, metal nitrate, metal phosphate, metal tetrafluoroborate; boron trifluoride; ammonium halide, ammonium sulfate, ammonium oxalate and phosphoric acid 6. Use according to claim 5, selected from ammonium salts from the group of diammonium; organic carboxylic acids, organic sulfonic acids, boric acid, sulfuric acid and hydrochloric acid.   Use according to claim 6, wherein the catalyst K is magnesium chloride.   Use according to any one of claims 5 to 7, wherein the concentration of the catalyst in the aqueous composition is in the range of 0.1 to 20% by weight, based on the total weight of the composition. A method for producing a molded article comprising a finely divided material based on lignocellulose, wherein the production method comprises:
i) Preparation of a particulate material based on lignocellulose treated with a curable aqueous composition, wherein the curable aqueous composition contains:
a) 1,2-bishydroxy bridging at least one N-bonded group of the formula CH ₂ OR, where R is hydrogen or C ₁ -C ₄ alkyl, and / or two nitrogen atoms of urea. Selected from urea compound H having an ethane-1,2-diyl group, initial condensate of urea compound H, and urea compound H, C ₁ -C ₆ alkanol, C ₂ -C ₆ polyol and oligoethylene glycol At least one crosslinkable urea compound from the group of reaction products or mixtures with at least one alcohol, and b) at least one catalyst K causing the crosslinking of the urea compound;
ii) Adhesive application of the lignocellulose-based microparticulate material obtained in step i) or a mixture of it with other microparticulate materials and a blend of liquid or powdered binders; and iii) shaped bodies Shaping and curing the adhesive-coated microparticulate material, or ii ′) mixing the treated lignocellulose-based microparticulate material obtained in step i) with a thermoplastic polymer And iii ′) a process for producing a shaped body comprising a finely divided material based on lignocellulose, including the shaping of the mixture to form a shaped body.   Treating the lignocellulose-based treated material by impregnating an untreated finely divided material based on lignocellulose with an aqueous composition and optionally carrying out drying and / or curing at elevated temperatures. 10. The method of claim 9, wherein the method is manufactured.   11. A method according to claim 9 or 10, wherein the particulate material is dried to a residual moisture of less than 30% with respect to dry matter prior to adhesive application in step ii).   The method according to claim 10 or 11, wherein the drying and / or curing is carried out at a temperature in the range of 50-220 ° C.   A treated microparticulate material based on lignocellulose in step i) is produced by impregnation with a curable aqueous composition and an essentially uncured material is adhesively applied in step ii) Item 10. The method according to Item 9.   The curable aqueous composition is used in an amount such that the curable component absorbed by the particulate material is in the range of 1 to 60% by weight relative to the dry matter of the untreated particulate material. The method of any one of these.   15. Process according to any one of claims 9 to 14, wherein the untreated finely divided material based on lignocellulose is selected from wood fibers, wood waste and wood pieces.   The method according to any one of claims 9 to 15, wherein the finely divided material based on lignocellulose is at least 80% by weight relative to the total weight of the finely divided material forming the compact.   The process according to any one of claims 9 to 16, wherein the binder used in step ii) comprises at least one thermosetting binder.   18. A process according to claim 17, wherein the thermosetting binder is used in the form of an aqueous formulation.   The method according to claim 17 or 18, wherein the thermosetting binder is selected from among aminoplast resins, phenol resins, isocyanate resins and polycarboxylic acid resins.   The method according to claim 9, wherein the binder is used in an amount of 0.5 to 20% by weight, based on the solid binder component, based on the total weight of the material forming the shaped body.   16. A drying and curing step is carried out in step i), and the particulate material thus obtained is mixed with at least one thermoplastic polymer and the mixture is subjected to a shaping method. The method of any one of these.   The method according to claim 21, wherein the thermoplastic polymer is 20 to 90% by mass relative to the total amount of the thermoplastic polymer and the molded body. Thermoplastic polymers, poly _-C 2 -C ₆ olefins, selected from among poly _-C 2 -C ₄ halogenated olefin and mixtures thereof, according to claim 21 or 22 A method according.   A molded body made of a finely divided material based on lignocellulose, obtained by the method according to any one of claims 9 to 23. A lignocellulose-based particulate material obtained by treatment of an untreated particulate material based on lignocellulose with an aqueous composition or by impregnation of wood with a curable aqueous composition, said The curable aqueous composition is
a) 1,2-bishydroxy bridging at least one N-bonded group of the formula CH ₂ OR, where R is hydrogen or C ₁ -C ₄ alkyl, and / or two nitrogen atoms of urea. Selected from urea compound H having an ethane-1,2-diyl group, initial condensate of urea compound H, and urea compound H, C ₁ -C ₆ alkanol, C ₂ -C ₆ polyol and oligoethylene glycol At least one crosslinkable urea compound from the group of reaction products or mixtures with at least one alcohol, and optionally b) at least one catalyst K causing the crosslinking of the urea compound
A microparticulate material based on lignocellulose, containing