DE102004019529A1 - Process for the production of moldings based on polyurethane binders and cellulose-containing material - Google Patents

Abstract

A process is disclosed for the production of moldings based on polyurethane binders and cellulose-containing material, DOLLAR A a) being selected as polyurethane binder at least one foam-forming two-component polyurethane adhesive, DOLLAR A b) the cellulose-containing material in the form of strips a thickness of 0.3 mm to 1.5 mm, preferably a thickness of 0.4 mm to 0.8 mm, a length of 80 to 300 mm, preferably a length of 100 to 250 mm, and a width of 10 to 45 mm, preferably 15 to 25 mm, DOLLAR A c) the cellulose-containing material and the polyurethane binder under a pressure of 1 × 10 × 5 × to 15 × 10 × 6 × Pa (0.1 MPa to 15 MPa) , preferably from 1 × 10 × 6 × 10 × 10 × 6 × Pa (1 MPa to 10 MPa), is glued together. DOLLAR A The moldings produced according to the invention are characterized by a high strength and elasticity at the same time low density. They also have very laminating surfaces.

Description

The The present invention relates to a process for the preparation of moldings based on polyurethane binders and cellulosic material, the shaped body itself, as well as its use.

to Production of moldings, in particular of wood moldings in the preferred embodiment as a plate, become wood particles like wood fibers or wood shavings glued with a binder under pressure and at elevated temperature.

The most important binders are urea-formaldehyde resins (UF resins), Phenol Formaldehyde Resins (PF Resins), Melamine Formaldehyde Resins (MF Resins) and melamine-urea-phenol-formaldehyde resins (MUPF resins).

When formaldehyde-free binder has diphenylmethane-4,4'-diisocyanate (MDI) established with a high oligomer content.

The Binders become common in non-foaming (compact) and foaming (foaming, porous) binder subdivided.

The Compact binders are preferred in practice for bonding of flat Substrates used to full-surface To achieve adhesive bonds with high strength. stable pasty Variants of these compact binders are used to bridge the gaps stick together. Foaming binder are used, on the other hand, if low adhesive strength is sufficient are and if gap-bridging too stick is. foaming Binders are preferably used when the application of pasty Adhesives for cavity filling, as in the bonding of chips or granules of low-density products, but with difficulty can be realized.

WO 99/30882 describes a process for the production of moldings consisting essentially of wood particles and / or cellulose-containing material (component A) and a porous polyurethane binder (component B) in a weight ratio of 0.05 to 1.0: 1.0 Component (B) to component (A) exist. It is proposed to carry out these shaped bodies by the reaction of at least one polyisocyanate with at least one polyol and / or polyamine and at least one carboxylic acid as blowing agent. The reaction is preferably carried out at temperatures between 80 and 100 ° C and with an initial pressure of more than 1 kp / cm ² . The gas formation and thus the end properties of the foamed molding should be largely independent of the moisture content of component (A).

When Component (A) is suitably Wood particles in the form of wood chips or wood flour with particle sizes of 1 mm maximum thickness, 20 mm maximum width and 50 mm maximum length (page 13, lines 1 to 3).

WO 97/03794 describes a process for the production of polymer wood moldings, wherein the polymer wood molded body by reacting wood particles and / or cellulose-containing material with at least one carbon dioxide splitting two-component polyurethane binder in a ratio of 10 to 200 parts by weight of binder on 100 parts by weight of wood particles and / or cellulose-containing material and under a pressure of at least 1 kp / cm ^{2 is} obtained. The wood particles are in the form of wood chips and / or wood flour in particle sizes of a maximum of 5 mm thick, 20 mm wide and 50 mm in length (page 6, lines 30 to 33).

WHERE No. 03/086750 describes a method for coating uneven substrates, in particular of wood-based surfaces, with thin ones Coating materials to a flat and uniformly smooth surface, wherein the carrier and the coating components against a smooth sheet metal, laminating rollers, structural bands or Like. Pressed and wherein as a coating material, a cover sheet film and an adhesive system is used, which is a foaming Adhesive comprises that of the topcoat film during coating chemical / physical reactions Defects of the coating to be coated Material filling and spanning Lends properties.

adversely in the known from the prior art method is often insufficient Strength of the molded article produced.

The Object of the present invention was therefore reproducible moldings produce with high strength values. The molding should in particular at least equivalent properties to plywood exhibit.

• a) als Polyurethanbindemittel mindestens einen schaumbildenden Zweikomponenten-Polyurethan-Klebstoff auswählt,
• b) das cellulosehaltige Material in Form von Streifen mit einer Dicke von 0,3 mm bis 1,5 mm, bevorzugt einer Dicke von 0,4 mm bis 0,8 mm, einer Länge von 80 bis 300 mm, bevorzugt einer Länge von 100 bis 250 mm, und einer Breite von 10 bis 45 mm, bevorzugt 15 bis 25 mm auswählt,
• c) das cellulosehaltige Material und das Polyurethan-Bindemittel unter einem Druck von 1 × 10⁵ bis 15 × 10⁶ Pa (0,1 MPa bis 15 MPa), bevorzugt von 1 × 10⁶ bis 10 × 10⁶ Pa (1 MPa bis 10 MPa) miteinander verklebt.

The solution of this problem can be found in the claims. It consists essentially of a process for the production of moldings based on polyurethane binders and cellulosic material, wherein

• a) selects as polyurethane binder at least one foam-forming two-component polyurethane adhesive,
• b) the cellulose-containing material in the form of strips having a thickness of 0.3 mm to 1.5 mm, preferably a thickness of 0.4 mm to 0.8 mm, a length of 80 to 300 mm, preferably a length of 100 up to 250 mm, and a width of 10 to 45 mm, preferably 15 to 25 mm,
• c) the cellulosic material and the polyurethane binder under a pressure of 1 × 10 ⁵ to 15 × 10 ⁶ Pa (0.1 MPa to 15 MPa), preferably from 1 × 10 ⁶ to 10 × 10 ⁶ Pa (1 MPa to 10 MPa) glued together.

The Weight fraction of the polyurethane binder is set to 0.5 to 25 parts by weight, preferably 1.0 to 15 parts by weight and in particular preferably 1.5 to 10 parts by weight per 100 parts by weight cellulose-containing Material.

The Process step (c) leads it is preferred at a temperature of 60 to 230 ° C, particularly preferably at a temperature of 80 to 160 ° C by. The reaction time in process step (c) is 0.5 up to 30 minutes, depending on the selected Apparatus in which the reaction is carried out. After completion of the reaction the pressure is released.

the Bonding process of Process step (c) under pressure and preferably at elevated temperature is preferably a mixing of the polyurethane binder with the preceded by cellulose-containing material (process step (d)). Process step (d) can be both continuous and batchwise respectively. The individual components of the polyurethane binder be doing the same time, but preferably offset in time cellulosic material mixed. Preferably, the first is Polyol component (resin) mixed with the cellulosic material, then the addition of the isocyanate component (hardener), if necessary followed by other auxiliaries, for example water repellents, each with continuous mixing.

suitable Mixing devices are mixing drums, preferably with baffles or Freefall cascade drums.

The Introducing the cellulose-containing material into a suitable device for the formation of the shaped body can be carried out in one layer, but preferably takes place in multiple layers. Concrete amounts the number of layers of the cellulose-containing material 1 to 10, preferably 2 to 8 and especially preferably 3 to 5 layers. For example, the introduction of the cellulosic material in 5 layers, the resulting from the process according to the invention produced moldings as five-layered glued molding designated. The layered introduction takes place in a specific Preferred direction, preferably it is done crosswise.

When Device in which the reaction between cellulose-containing material and polyurethane binders are carried out are: closed Molds, molds with movable stamp, 1-level or multi-level presses, Plate presses with or without form or belt or double belt presses. In the latter, the relaxation of the press pressure is characterized that the formed molding leaves the print area continuously.

at the implementation of the procedure in closed forms, in forms with moving ones Stamp or in plate presses, it is appropriate that after the relaxation step the reaction product is cooled and only after cooling the shaping device is removed. In these cases can it should be necessary the reacted molding only at temperatures below 40 ° C to 80 ° C of the shaping device refer to. In the method according to the invention it is preferred to use pressure-tight forms.

Usually, it is necessary to provide a release agent between the mold and the molded body, for example, a ^Teflon® layer. In certain cases, however, it is preferred to use Acmos release agents for PUR with the type designations 39-5001, 39-4487, 37-3200 and 36-3182. In the context of the process according to the invention, the addition of internal release agents is preferred.

Surprisingly, it has been found that by selecting at least one foam-forming two-component polyurethane adhesive as binder and by selecting a cellulose-containing material in the form of strips having a thickness of 0.3 mm to 1.5 mm, preferably a thickness of 0.4 mm to 0.8 mm, a length of 80 to 300 mm, preferably a length of 100 to 250 mm and a width of 10 to 45 mm, preferably 15 to 25 mm, moldings having excellent mechanical properties, in particular high bending strengths, E Moduli and increased moisture resistance can be obtained. The ratio of strip length to strip width is preferably from 30: 1 to 6: 1, particularly preferably from 20: 1 to 6: 1 and particularly preferably from 10: 1 to 7: 1. Particularly preferably, the strips of the cellulose-containing material have a uniform quality in terms of thickness and width. Process for the production of strips of uniform quality are from the DE 197 27 127 C1 and the DE 10035052 C1 known.

Under Cellulosic materials are understood as materials that Contain cellulose as a component. In particular, the term "cellulosic Materials "Materials wooden.

In a particularly preferred embodiment the method according to the invention are used as cellulosic material veneer strips from the group of Coniferous and deciduous tree woods used. The woods will be divided into softwood and hardwood species. From the group of softwood species are veneer strips of spruce, pine, Fir, Larch, Birch, Alder, Horse Chestnut, of pine, Aspen, willow, poplar or linden wood.

Out the group of hardwood species are veneer strips made of beech, hawthorn, Sloe, ash, maple, walnut, apple tree, pear tree, yew or oak wood. Particularly preferred are veneer strips of birch, Poplar, pine and spruce wood.

For the inventive method It is also essential that as a polyurethane binder at least select a foam-forming two-component polyurethane adhesive.

Of the Two-component polyurethane adhesive is available by implementation of at least one polyisocyanate with at least one polyol and / or Polyamine. The two-part polyurethane adhesive contains during the Reaction at least one blowing agent, wherein the blowing agent is a microporous Structure in the form of a polyurethane foam causes. The use of the foaming Two-component polyurethane adhesive is important for weight reduction compared to compact binder systems. On the other hand will the foaming pressure also exploited, the penetration of the cellulosic to be bound Material in the form of strips through the components of the foaming Two-component polyurethane adhesive effect. It can be a chemical reaction between the cellulosic material and the Polyurethane binder done. This results in a total of one very strong bond between the binder and the cellulosic Material.

The Polyisocyanates are polyfunctional, preferably containing suitable polyfunctional isocyanates on average 2 to at most 5, preferably to 4 and especially 2 or 3 isocyanate groups per molecule. The polyisocyanates to be used may be aromatic, cycloaliphatic or aliphatic isocyanates.

Examples of suitable aromatic polyisocyanates are: All isomers of toluene diisocyanate (TDI) either in isomerically pure form or as a mixture of several isomers, naphthalene-1,5-diisocyanate, diphenylmethane-4,4'-diisocyanate (MDI), diphenylmethane-2,4 ' diisocyanate and mixtures of the 4,4'-diphenylmethane diisocyanate with the 2,4'-isomer or mixtures thereof with higher-functional oligomers (so-called crude MDI), xylylene diisocyanate (XDI), 4,4'-diphenyl-dimethylmethane diisocyanate, diisocyanate and tetraalkyl diphenylmethane diisocyanate, 4,4'-dibenzyl diisocyanate, 1,3-phenylene diisocyanate, 1,4-phenylene diisocyanate. Examples of suitable cycloaliphatic polyisocyanates are the hydrogenation products of the abovementioned aromatic diisocyanates, for example 4,4'-dicyclohexylmethane diisocyanate (H12MDI), 1-isocyanatomethyl-3-isocyanato-1,5,5-trimethylcyclohexane (isophorone diisocyanate, IPDI), Cyclohexane-1,4-diisocyanate, hydrogenated xylylene diisocyanate (H6XDI), 1-methyl-2,4-diisocyanato-cyclohexane, m- or p-tetramethylxylene diisocyanate (m-TMXDI, p-TMXDI) and dimer fatty acid diisocyanate. Examples of aliphatic polyisocyanates are tetramethoxybutane-1,4-diisocyanate, butane-1,4-diisocyanate, hexane-1,6-diisocyanate (HDI), 1,6-diisocyanato-2,2,4-trimethylhexane, 1,6- Diisocyanato-2,4,4-trimethylhexane, butane-1,4-diisocyanate and 1,12-dodecane diisocyanate (C12DI).

in the In general, aromatic isocyanates are preferred, preferably diphenylmethane diisocyanate, either in the form of pure isomers, as isomeric mixtures of 2,4 '- / 4,4'-isomers or also the liquefied with carbodiimide MDI, e.g. is known under the trade name Isonate 143 L, as well as the so-called "crude MDI", i. an isomer / oligomer mixture of the MDI, as e.g. under the trade name PAPI or Desmodur VK commercially available are. Furthermore you can so-called "quasi-prepolymers", i. reaction products of MDI or TDI with low molecular weight diols, e.g. Ethylene glycol, Diethylene glycol, propylene glycol, dipropylene glycol or triethylene glycol be used. These quasi-prepolymers are known to provide a Mixture of the aforementioned reaction products with monomeric diisocyanates. Amazingly able also aliphatic and cycloaliphatic isocyanates even at low temperatures fast and complete to the in the process according to the invention to react usable foams. In addition to the aforementioned Aliphatic and cycloaliphatic isocyanates are also their Isocyanuration or biuretization, in particular to use those of the HDI or IPDI.

in principle are all polyols already known for polyurethane production are, too, for the present invention suitable. In particular, be considered the known polyhydroxy polyethers of the molecular weight range from 60 to 10,000, preferably 70 to 6,000, with 2 to 10 hydroxyl groups per Molecule. Such polyhydroxypolyethers are known per se obtained by alkoxylation of suitable starter molecules, for. From water, Propylene glycol, glycerin, trimethylolpropane, sorbitol, cane sugar etc. Suitable alkoxylating agents are in particular propylene oxide and possibly also ethylene oxide.

Preferably are the liquid ones Polyhydroxy compounds having two or three hydroxyl groups per molecule, e.g. di- and / or trifunctional polypropylene glycols in the molecular weight range from 200 to 6000, preferably in the range of 400 to 3000. It can also random and / or block copolymers of ethylene oxide and propylene oxide be used. Another group of preferably used polyethers are the polytetramethylene glycols, e.g. by the acidic polymerization be prepared from tetrahydrofuran, this is the molecular weight range the polytetramethylene glycols between 200 and 6000, preferably in the range of 400 to 4000.

Farther are the polyols as the liquid Polyester suitable by condensation of di- or tricarboxylic acids, such as e.g. adipic acid, sebacic, glutaric, azelaic acid, hexahydrophthalic or phthalic acid with low molecular weight diols or triols, e.g. Ethylene glycol, Propylene glycol, diethylene glycol, triethylene glycol, dipropylene glycol, 1,4-butanediol, 1,6-hexanediol, 1,10-decanediol, glycerol or trimethylolpropane can be produced.

A another group of the invention to be used Polyols are the polyesters based on caprolactone, also called "polycaprolactones".

It can but also polyester polyols of oleochemical origin can be used. Such polyester polyols can for example, by complete ring opening of epoxidized triglycerides of at least partially olefinic unsaturated containing fatty acid Fat mixture with one or more alcohols having 1 to 12 carbon atoms and subsequently partial transesterification of the triglyceride derivatives to alkylester polyols be prepared with 1 to 12 carbon atoms in the alkyl radical. Other suitable Polyols are polycarbonate polyols and dimer diols (Henkel) as well as castor oil and its derivatives. Also the hydroxyfunctional polybutadienes, as they are e.g. available under the trade name "Poly-bd" are, can for the Compositions of the invention be used as polyols.

Especially For example, the polyol component is a diol / triol blend of polyether and polyester polyols.

Carboxylic acids are preferably used in the process according to the invention. These react with the isocyanates in the presence of catalysts with elimination of carbon dioxide to form amides. So you have the dual function of being involved in the structure of the polymer backbone and at the same time by the elimination of carbon dioxide as a blowing agent, possibly with the concomitant use of water to act. By "carboxylic acids" is meant acids containing one or more, preferably up to three, carboxyl groups (-COOH) and at least 2, preferably 5 to 400, carbon atoms. The carboxyl groups may be linked to saturated or unsaturated, linear or branched alkyl or cycloalkyl radicals or to aromatic radicals. They can be further groups such as ether, ester, halogen, amide, amino, hydroxy and urea groups. However, preferred are carboxylic acids which are readily incorporated as liquids at room temperature, such as native fatty acids or fatty acid mixtures, COOH-terminated polyesters, polyethers or polyamides, dimer fatty acids and trimer fatty acids. Specific examples of the carboxylic acids are: acetic acid, valeric, caproic, caprylic, capric, lauric, myristic, palmitic, stearic, isostearic, isopalmitic, arachinic, beehive, cerotin and melissin Acids and the mono- or polyunsaturated acids palmitoleic, oleic, elaidin, petroselin, eruca, linoleic, linolenic and gadoleic acid. In addition, may also be mentioned: adipic acid, sebacic acid, isophthalic acid, terephthalic acid, trimellitic acid, phthalic acid, hexahydrophthalic acid, tetrachlorophthalic acid, oxalic acid, muconic acid, succinic acid, fumaric acid, ricinoleic acid, 12-hydroxystearic acid, citric acid, tartaric acid, di- or trimerized unsaturated fatty acids, optionally in admixture with monomeric unsaturated fatty acids and optionally partial esters of these compounds. It is likewise possible to use esters of polycarboxylic acids or carboxylic acid mixtures which have both COOH and OH groups, such as esters of TMP [C 2 H 5-C (CH 2 OH) 3], glycerol, pentaerythritol, sorbitol, glycol or their alkoxylates with adipic acid, Sebacic acid, citric acid, tartaric acid or grafted or partially esterified carbohydrates (sugar, starch, cellulose) and ring-opening products of epoxides with polycarboxylic acids.

In addition to the aminocarboxylic acids, the "carboxylic acids" preferably include "hydroxycarboxylic acids". "Hydroxycarboxylic acids" are monohydroxymonocarboxylic acids, monohydroxypolycarboxylic acids, polyhydroxymonocarboxylic acids and polyhydroxypolycarboxylic acids including the corresponding hydroxyalkoxycarboxylic acids having from 2 to 600, preferably from 8 to 400 and in particular from 14 to 120 carbon atoms which are 1 to 9, preferably 2 to 3, hydroxyl groups or Contain carboxyl groups on an HC radical, in particular on an aliphatic radical. The polyhydroxymonocarboxylic acids and the polyhydroxypolycarboxylic acids, including the corresponding hydroxyalkoxycarboxylic acids, are combined to form the polyhydroxy fatty acids. The dihydroxy fatty acids preferably used and their preparation are described in DE-A-33 18 596 and EP 237 959 described, to which reference is expressly made.

The used according to the invention polyhydroxyfatty are preferably derived from natural occurring fatty acids from. They therefore usually have an even number of carbon atoms in the main chain and are not branched. Particularly suitable are those with a chain length from 8 to 100, especially from 14 to 22 carbon atoms. For technical Uses become natural fatty acids mostly used as technical mixtures. These mixtures preferably contain a part of oleic acid. You can also add more saturated, monounsaturated and polyunsaturated fatty acids contain. Also in the preparation of the invention used polyhydroxyfatty or polyhydroxyalkoxy fatty acids can In principle, mixtures of different chain lengths are used, the also saturated Contain shares or polyhydroxyalkoxycarboxylic acids with double bonds can. Thus, not only the pure polyhydroxy fatty acids are suitable here, but also also mixed products obtained from animal fats or vegetable oils, which after treatment (ester cleavage, purification stages) contents of monounsaturated Fatty acids> 40%, preferably> 60%. Examples therefor are for sale available, natural Raw materials such as e.g. Beef tallow with a chain distribution of 67 % Oleic acid, 2% stearic acid, 1% heptadecanoic acid, 10% saturated acids the chain length C12 to C16, 12% linoleic acid and 2% saturated acids> C18 carbon atoms or e.g. the oil the new sunflower (NSb) with a composition of approx. 80 % Oleic acid, 5% stearic acid, 8% linoleic acid and about 7% palmitic acid. These products can after ring opening be distilled briefly to the unsaturated fatty acid ester portions to reduce. More Purification steps (e.g., longer sustained distillation) are also possible.

Prefers are the inventively used polyhydroxyfatty of monounsaturated fatty acids from, e.g. of 4,5-tetradecenoic acid, 9,10-tetradecenoic acid, 9,10-pentadecenoic acid, 9,10-hexadecenoic acid, 9,10-heptadecenoic acid, 6,7-octadecenoic acid, 9,10-octadecenoic acid, 11,12-octadecenoic acid, 11,12-eicosenoic acid, 11, 12-docosenoic acid, 13,14-docosenoic acid, 15,16-tetracenoic acid and 9,10-Ximensäure. Of these, preferred is oleic acid (9,10-octadecenoic acid). Either cis and trans isomers of all the fatty acids mentioned suitable.

Suitable are also polyhydroxy fatty acids, which are less common Derive occurring unsaturated fatty acids, like decyl-12-enoic acid, Stilingsäure, Dodecyl-9-enoic acid, ricinoleic, Petroselinic acid, vaccenic acid, elaeostearic acid, punicic acid, licanic acid, parinaric acid, gadoleic acid, arachidonic acid, 5-eicosenoic acid, 5-docosenoic acid, cetoleic acid, 5,13-docosadienoic acid and / or Selacholeic.

Also suitable are polyhydroxy fatty acids prepared from isomerization products of natural unsaturated fatty acids. The polyhydroxy fatty acids thus produced differ only in the position of the hydroxy or hydroxyalkoxy groups in the molecule. They are generally considered as Mixtures in front. Naturally occurring fatty acids are preferred in the context of natural raw materials in the present invention as the starting component, but this does not mean that not synthetically produced carboxylic acids are suitable with corresponding C numbers.

One Hydroxyalkoxy of the polyhydroxy fatty acids is derived from the polyol from that to the ring opening of the epoxidized fatty acid derivative has been used. Preference is given to polyhydroxy fatty acids whose Hydroxyalkoxygruppe of preferably primary difunctional alcohols with up to 24, in particular up to 12 carbon atoms derived. suitable Diols are propanediol, butanediol, pentanediol and hexanediol, dodecanediol, preferably 1,2-ethanediol, 1,4-butanediol, 1,6-hexanediol, polypropylene glycol, polybutanediol and / or polyethylene glycol having a degree of polymerization of 2 to 40. Furthermore, as the diol compounds polypropylene glycol and / or Polytetrahydrofurandiol and their Mischpolymerisationsprodukte particularly suitable. This is especially true when these compounds each have a degree of polymerization of about 2 to 20 units. For ring opening can but also triplets or even higher quality Alcohols are used, e.g. Glycerol and trimethylolpropane and their adducts of ethylene oxide and / or propylene oxide with molecular weights up to 1500. Polyhydroxy fatty acids are then obtained with more than 2 hydroxyl groups per molecule.

to ring opening may instead of a polyol as a hydroxyl group-containing compound also a hydroxycarboxylic acid can be used, e.g. Citric acid, ricinoleic acid, 12-hydroxystearic acid, lactic acid. It will arise then Ester groups in place of ether groups. Furthermore, you can also Amines, hydroxyl-bearing amines or aminocarboxylic acids to ring opening be used.

Prefers but are dihydroxy fatty acids, used in particular from diols. They are at room temperature liquid and blend easily with the rest Reaction participants mix. Under dihydroxy fatty acids are For the purposes of the invention, both the ring-opening products epoxidized unsaturated fatty acids with water as well as the corresponding ring opening products with diols and their crosslinking products understood with other epoxy molecules. The ring opening products with diols can more accurately also referred to as Dihydroxyalkoxyfettsäuren. there are preferably the hydroxy groups or the hydroxyalkoxy group by at least 1, preferably at least 3, in particular at least 6, CH2 units separated from the carboxy group.

Preferred dihydroxy fatty acids are:
9,10-Dihydroxypalmitinsäure, 9,10-dihydroxystearic acid and 13,14-Dihydroxybehensäure and their 10,9 and 14,13 isomers.

Also polyunsaturated fatty acids are suitable, e.g. linoleic acid and linolenic acid.

When concrete example for an aromatic carboxylic acid be the cinnamic acid called. The blowing reaction, d. H. the CO2 formation for the foaming can both by the reaction of isocyanate groups of the polyisocyanate with water as well as by the reaction of the isocyanate groups with the carboxylic acid groups of carboxylic acids respectively.

If the CO2 cleavage from the isocyanate-carboxylic acid reaction already at low Temperature should start, it is appropriate amino-substituted pyridines and / or N-substituted imidazoles as catalysts with. Particularly suitable are 1-methylimidiazole, 2-methyl-1-vinylimidazole, 1-Allylimidazole, 1-phenylimidazole, 1,2,4,5-tetramethylimidazole, 1 (3-aminopropyl) imidazole, Pyrimidazole, 4-dimethylaminopyridine, 4-pyrrolidinopyridine, 4-morpholino-pyridine, 4-methylpyridine and N-dodecyl-2-methyl-imidazole.

The above mentioned starting materials for the PU binder, namely Polyisocyanate, polyol, polyamine, water, carboxylic acid and catalyst in the following proportions used: to an equivalent Isocyanate comes from 0.1 to 1, preferably 0.8 to 1 equivalents a mixture of polyol, polyamine, water and / or carboxylic acid, wherein The relationship Polyol and / or polyamine to water and / or carboxylic acid 20: 1 to 1: 20 may be. The amount of the reactants polyisocyanate, Polyol, polyamine, carboxylic acid and water is especially chosen so that the polyisocyanate used in excess becomes. The equivalent ratio of NCO- to the sum of OH, NH and COOH groups is 5: 1, preferably 2: 1 to 1.2: 1, most preferably is a Isocyanate excess of 5 until 50 %.

The amount of catalysts to be used is between 0.0001 and 1.0, preferably between 0.01 and 0.5 equivalents of pyridine or imidazole catalyst. If, in contrast, only water is used for the blowing reaction, it is possible to dispense with the addition of the abovementioned pyridines and imidazoles. Is Car, however Bonsäure the sole blowing agent, these pyridines and / or imidazoles must be used in combination with the later listed basic or organometallic catalysts to accelerate the reaction. If one uses polycarboxylic acids or hydroxy or aminocarboxylic acids, can be completely dispensed with the addition of a polyol or polyamine. In the event that no polyol, polyamine or water is involved in the reaction, ie the isocyanates are reacted with the carboxylic acids, the rule applies: to one equivalent of isocyanate are 0.1 to 1, preferably 0.8 to 1 equivalent carboxylic acid and 0.0001 to 1.0, preferably 0.001 to 0.5 equivalents of pyridine or imidazole catalyst.

In the case, that the polyvalent isocyanates predominantly with hydroxycarboxylic acids to be implemented, the o.g. Amine catalysts preferably in a concentration of 0.05 to 15, in particular from 0.5 to 10 wt .-% are used, based on the sum of hydroxycarboxylic acid and Isocyanate.

Next The above-mentioned pyridine and imidazole derivatives can still additional catalysts are added. In particular for the isocyanate / polyol and isocyanate / water reaction can organometallic compounds such as tin (II) salts of carboxylic acids, strong Bases such as alkali hydroxides, alcoholates and phenolates, e.g. Stannous acetate, ethylhexoate and diethylhexoate. A preferred Compound class represent the dialkyl-tin (IV) carboxylates. The carboxylic acids have 2, preferably at least 10, in particular 14 to 32 C-atoms. It can also dicarboxylic acids be used. As acids are expressly called: adipic acid, maleic acid, fumaric acid, malonic, Succinic acid, pimelic, terephthalic acid, phenylacetic acid, benzoic acid, Acetic acid, propionic and in particular 2-ethylhexane, caprylic, capric, lauric, myristic, Palmitic and stearic acid. Specific compounds are dibutyl and dioctyltin diacetate, maleate, bis (2-ethylhexoate), dilaurate, tributyltin acetate, bis (β-methoxycarbonylethyl) tin dilaurate and bis (β-acetyl-ethyl) tin dilaurate.

Tin oxides and sulfides and thiolates are also useful. Specific compounds are: bis (tributyltin) oxide, bis (trioctyltin) oxide, dibutyl and dioctyltin bis (2-ethylhexylthiolate) dibutyl and dioctyltin dodecylthiolate, bis (β-methoxycarbonylethyl) tin dodecylthiolate, bis (β-acetylthiolate) ethyl) tin bis (2-ethylhexyl thiolate), dibutyl and dioctyl tin dodecyl thiolate, butyl and octyl tin tris (thioglycolic acid 2-ethylhexoate), dibutyl and dioctyltin bis (thioglycolic acid 2-ethylhexoate), tributyl and trioctyltin (thioglycolic acid 2-ethylhexanoate), butyl- and octyltin tris (thioethylene glycol-2-ethylhexoate), dibutyl- and dioctyltin bis (thioethylene glycol-2-ethylhexoate), tributyl- and trioctyltin (thioethylene glycol-2-ethylhexoate) having the general formula R _{n + 1} Sn (SCH ₂ CH ₂ OCOC ₈ H ₁₇ ) _3-n , wherein R is an alkyl group having 4 to 8 C atoms, bis (β-methoxycarbonyl-ethyl) tin bis (thioethylene glycol 2-ethylhexoate), bis (methoxycarbonyl ethyl) tin bis (thioglycolic acid 2-ethylhexoate), and bis (β-acetyl-ethyl) tin bis (thioethylene glycol 2-ethylhe xoate) and bis (acetyl-ethyl) tin bis (thioglycolic acid 2-ethyl-hexoate.

For networking of the polyurethane framework may also involve the trimerization reaction of the isocyanate groups themselves or with urethane and urea groups to allophanate or Biuret groups take place. For this purpose, trimerization catalysts be used. As a trimerization catalyst is DABCO TMR-2 etc. of the company called Air Products, which are in ethylene glycol dissolved quaternary Ammonium salts is.

Additionally suitable are also aliphatic tertiary Amines especially with cyclic structure. Among the tertiary amines are also suitable, in addition to the Isocyanate-reactive groups, in particular hydroxyl and / or Amino groups. Specific examples include: dimethylmonoethanolamine, diethylmonoethanolamine, Methylethylmonoethanolamine, triethanolamine, trimethanolamine, tripropanolamine, Tributanolamine, trihexanolamine, tripentanolamine, tricyclohexanolamine, Diethanolmethylamine, diethanolethylamine, diethanolpropylamine, diethanolbutylamine, Diethanolpentylamine, diethanohexylamine, diethanolcyclohexylamine, Diethanolphenylamine and its ethoxylation and propoxylation products, diaza-bicyclooctane (DABCO), Triethylamine, dimethylbenzylamine (Desmorapid DB, BAYER), bis-dimethylaminoethyl ether (Calalyst A I, UCC), tetramethylguanidine, bis-dimethylaminomethyl-phenol, 2,2'-dimorpholinodiethyl ether, 2- (2-dimethylaminoethoxy) ethanol, 2-dimethylaminoethyl-3-dimethylaminopropyl ether, bis (2-dimethylaminoethyl) ether, N, N-dimethylpiperazine, N- (2-hydroxyethoxyethyl) -2-azanorborane, Texacat DP-914 (Texaco Chemical), N, N, N, N-tetramethylbutane-1,3-diamine, N, N, N, N-tetramethylpropane-1,3-diamine and N, N, N, N-tetramethylhexane-1,6-diamine.

The Catalysts can also in oligomerized or polymerized form, e.g. as N-methylated polyethyleneimine.

The polyurethane binders of the shaped bodies produced according to the invention have, in addition to the amide groups due to the carboxylic acid / isocyanate reaction nor urethane groups from the reaction of the isocyanates with the polyols and / or polyhydroxycarboxylic acids. They also contain urea groups from the reaction of the isocyanates with the optionally present water, the polyamines or aminocarboxylic acids of the system. They also contain ester groups or ether groups from the polyols used.

In a further embodiment the method according to the invention is the polyurethane binder and / or the cellulose-containing material at least one auxiliary from the group: fillers, water repellents, Release agents and foam stabilizers added. The excipients are preferably completely or partially admixed with the polyol component. The term auxiliaries means substances which are used in the Rule (except fillers) be added in small amounts to the properties of the essential Components in desired Change direction, e.g. their processability, storability and also use properties to adapt to the specific field of application.

When fillers are suitable opposite Isocyanates non-reactive inorganic compounds such as chalk, coated chalk, limestone, calcium-magnesium carbonates, aluminum oxides and hydroxides, precipitated silica, Zeolites, bentonites, glass, ground minerals and others in the field of work Specialist known inorganic fillers. Preferred fillers are chalk, modified or unmodified.

When Hydrophobing agents are particularly suitable paraffin waxes.

When Release agents are called solid or liquid substances, the adhesion between two adjoining surfaces, in particular reduce between shape and shaped body, d. H. you Prevent sticking by placing one between both surfaces to form easily separable film. Release agents are in the form of dispersions (Emulsions or suspensions), sprays, pastes, powders and permanent, mostly baked release films applied. The latter can through spraying, Brushing or dipping the mold and subsequent burn-in generated become. At least one is preferred in the process according to the invention used internal release agent. Internal release agents are in the to be demobilized good and have the assets to themselves either on the surface of the molding (Molding) or faster curing of the surface to cause it to be between mold wall and shaped body too can not come together.

release agent are: silicones (in the form of oils, oil emulsions in water, fats and resins), waxes (essentially natural and synthetic paraffins with and without functional groups), metal soaps (Metal salts of fatty acids, such as calcium, lead, magnesium, aluminum, zinc stearate), fats, Polymers (polyvinyl alcohol, polyesters and polyolefins), fluorocarbons or inorganic release agents in the form of powders (such as graphite, talc and mica). Preference is given to: dispersions of waxes, modified Silicones and organic polymers in carrier oils, water or alcohols.

especially preferred internal release agents for Foaming two-component polyurethane adhesives are commercial from the company Würtz GmbH & Co. KG, Bingen sponsorship under the name PAT release agent available.

When Foam stabilizers are especially polyether siloxanes in question. These compounds are generally constructed so that a copolymer of ethylene oxide and propylene oxide with a polydimethylsiloxane radical connected is. Of particular interest are often allophanate groups branched polysiloxane-polyoxyalkylene copolymers. Are suitable also other Organospolysiloxane, oxyethylierte alkylphenols, oxyethylierte Fatty alcohols, and / or paraffin oils. To improve the emulsifying effect, the dispersion of the filler, the cell structure and / or for their stabilization are also suitable oligomeric polyacrylates having polyoxyalkylene and fluoroalkane radicals as page groups. It is also possible to add cell regulators known per se such as paraffins, fatty alcohols or dimethylpolysiloxanes.

Further suitable auxiliaries are pigments or dyes, flame retardants, e.g. Tris-chloroethyl phosphate, tricresyl phosphate or ammonium phosphate and polyphosphate, stabilizers against aging and weathering, plasticizers as well as fungistatic and bacteriostatic substances.

One Another object of the present invention is according to the produced according to the invention Moldings.

• – Er kann in beliebiger Form, also maßgeschneidert, beispielsweise in Form von Platten, Leisten, Würfeln, Quadern usw. hergestellt werden.
• – Er ist als Leichtbaustoff geeignet, da er üblicherweise – in Abhängigkeit vom Druck, der Beschaffenheit der celluloshaltigen Materialien, insbesondere der Hölzer (Größe und Größenverteilung) sowie der Polyurethanbindemittelmenge und Polyurethanbindemittelzusammensetzung – eine Dichte von 300 kg/m³ bis 800 kg/m³, bevorzugt von 400 kg/m³ bis 700 kg/m³, insbesondere von 450 bis 600 kg/m³ aufweist.
• – Er ist ein neuer Werkstoff, insbesondere eine Alternative zu Sperrhölzern aller Art.
• – Die mechanischen Eigenschaften liegen auf hohem Niveau, insbesondere die Festigkeiten und Elastizitätswerte übertreffen die von Sperrhölzern.
• – Der Formkörper besitzt eine sehr hohe Schraubenauszugsfestigkeit
• – Er ist weiter so formstabil, dass man Gewinde hineinschneiden kann.
• – Er ist ohne weiteres lackierbar.
• – Er zeichnet sich durch eine hervorragende Wasserbeständigkeit aus.
• – Alle Gebrauchseigenschaften des Formkörpers sind trotz unterschiedlicher Feuchtegehalte des eingesetzten cellulosehaltigen Materials gut zu reproduzieren, da sich die Schaumbildung des Polyurethanbindemittels entsprechend justieren lässt.

The molding according to the invention has the following remarkable properties:

• - It can be made in any form, so tailored, for example in the form of plates, strips, cubes, cuboids, etc.
• - It is suitable as a lightweight construction material, since it usually - depending on the pressure, the nature of the cellulosic materials, especially the woods (size and size distribution) and the polyurethane binder amount and polyurethane binder composition - a density of 300 kg / m ³ to 800 kg / m ³ , preferably from 400 kg / m ³ to 700 kg / m ³ , in particular from 450 to 600 kg / m ³ .
• - It is a new material, especially an alternative to plywood of all kinds.
• - The mechanical properties are at a high level, in particular the strengths and elasticity values exceed those of plywoods.
• - The molding has a very high screw extraction strength
• - He is still so dimensionally stable that you can cut threads.
• - He is easily paintable.
• - It is characterized by excellent water resistance.
• - All use properties of the molding are well reproduce despite different moisture contents of the cellulose-containing material used, since the foaming of the polyurethane binder can be adjusted accordingly.

The Form of the molding according to the invention is in principle arbitrary. His preferred form is that of a cube, cuboid, a plate, a strip or a cylinder. Especially preferred is the embodiment of the molding as a plate, in particular as a wood-based panel.

• a) Spanplatten (chipboard) in Form von Strangpressplatten (Vollplatte-SV oder Röhrenplatte-SR) für allgemeine Zwecke wie Möbel oder Innenausbau, Rohdichte: zwischen 600 und 680 kg/m³.
• b) FPY-Spanplatten (DIN 68761-1) sind Flachpressplatten mit besonderen dichten Deckschichten, Rohdichte: zwischen 700 und 750 kg/m³.
• c) FPO-Spanplatten (DIN 68761-4) sind Flachpressplatten für die Direktlackierung, Beschichtung oder Folienkaschierung, Rohdichte: ca. 750 kg/m³.
• d) OSB (Oriented Strand Board)-Platte, ein Produkt aus Spänen („strands") unterschiedlicher Geometrie, die entweder nur längs orientiert einschichtig oder über Kreuz gestreut, mit quer liegender Mittelschicht; Rohdichte: zwischen 500 und 750 kg/m³.
• e) Holzfaserhartplatten für Rückwände, Schubkastenböden oder Formkörper, Rohdichte: ca. 1.000 kg/m³.
• f) MDF-Platten (MDF = medium density fiberboard), als mitteldicht geltende Produkte, Rohdichte: um 850 kg/m³. Die Streubreite der Dichte liegt zwischen 600 und 900 kg/m³, mit der Bezeichnung 'LDG' für 'Low densitiy fiberboard' und 'HDF' für 'High density fiberboard'.
• g) Sperrholz (plywood); Holzwerkstoff aus kreuzweise verleimten Holzschichten (je Schicht um 90° gekreuzter Faserverlauf), Rohdichte 400 kg/m³ bis 500 kg/m³. Sperrholz aus parallel verleimten Furnierlagen wird als LVL (Laminated Veneer Lumber) bezeichnet. Das so genannte Spanstreifenholz (LSL = Laminated Strand Lumber) weist eine mit OSB vergleichbare Struktur auf.
• h) Stabmassivholzplatten, gedeckt mit Stabsperrholz (ST) oder auch Stäbchensperrholz (STAE). Diese hochwertigen Platten werden aufgrund ihres guten verspannungsarmen Stehvermögens nur für hochwertigen Möbelbau verwendet.

In the case of wood-based panels, the following distinction is made:

• a) Chipboard in the form of extruded plates (full plate SV or tubular plate SR) for general purposes such as furniture or interior work, density between 600 and 680 kg / m ³ .
• b) FPY chipboard (DIN 68761-1) are flat-pressed boards with special dense surface layers, bulk density: between 700 and 750 kg / m ³ .
• c) FPO chipboards (DIN 68761-4) are flat-pressed boards for direct painting, coating or film lamination, gross density: approx. 750 kg / m ³ .
• d) OSB (Oriented Strand Board) sheet, a product of strands of different geometry, either longitudinally oriented single-layered or cross-scattered, with transverse middle layer, apparent density between 500 and 750 kg / m ³ .
• e) Hardboard wood for rear walls, drawer bottoms or shaped bodies, gross density: approx. 1,000 kg / m ³ .
• f) medium density fiberboard (MDF), medium density products, bulk density: around 850 kg / m ³ . The range of the density is between 600 and 900 kg / m ³ , with the designation 'LDG' for 'Low density fiberboard' and 'HDF' for 'High density fiberboard'.
• g) plywood (plywood); Wood material of cross-laminated wood layers (each layer crossed by 90 ° fiber), bulk density 400 kg / m ³ to 500 kg / m ³ . Plywood made of parallel laminated veneer sheets is called LVL (Laminated Veneer Lumber). The so-called Laminated Strand Lumber (LSL) has a structure comparable to OSB.
• h) Solid solid wood slabs covered with plywood (ST) or also plywood (STAE). These high quality panels are used only for high quality furniture because of their good low-tension stamina.

Prefers is the shaped body according to the invention as Veneer strip plate designed. The veneer strip plate is from 1 to 10 layers, preferably 2 to 8 and especially preferred 3 to 5 layers built up. Preferably, it is in the form of three layers cross-glued wooden material panel made of veneer strips.

The according to the inventive method produced moldings are produced as plates or semi-finished products with a thickness of 2 to 40 mm. The veneer strip plate according to the invention has a thickness of 2 to 40 mm, preferably 2 to 20 mm, in particular 2 to 10 mm.

The veneer strip plate according to the invention is almost formaldehyde-free: For The production of OSB boards are usually MF, UF or MUPF resins used, Accordingly, formaldehyde emission values are interposed between these plates 6.0-8.0 mg / 100g. The veneer strip panels according to the invention however, have formaldehyde emission levels between 0.6-0.7 mg / 100 g, wherein this emitted formaldehyde directly from the natural product Wood is discharged.

The veneer strip boards produced according to the invention have opposite commercial OSB panels have a smooth surface that matches the quality of MDF, chipboard and plywood panels. For specimens that are destroyed by cohesive failure, microscopic examination reveals that the moldings are three-dimensionally microporous foamed and that there are often closed cavities, some of which are honeycomb-shaped. Even with a low polyurethane binder content, ie between 3 and 10 parts by weight, in particular between 4 and 6 parts by weight of polyurethane binder, based on 100 parts by weight of dried wood with simultaneously low densities, ie between 300 kg / m ³ and 800 kg / m ³ , preferably 400 to 700 kg / m ³ , particularly preferably 450 to 600 kg / m ³ high strength and high flexibility of the plates or semi-finished products are achieved. Such veneer strip boards surpass the strength of chipboard, MDF boards or conventional OSB boards, and at least achieve the strength values of the much more expensive plywood boards.

by virtue of a significantly lower weight and other physical Properties, such as a very high flexural strength or a very high high Schraubauszugsfestigkeit and also their much lower Swelling behavior own the shaped bodies according to the invention, in particular the veneer strip panels according to the invention, for the production of boards or semi-finished products for furniture, kitchen worktops, floors, walls, stairs or blankets.

The The present invention therefore also relates to the use of the molding of aforementioned type or manufactured according to the above type in shape plates, moldings, cubes, Ashlar, etc. Furthermore, the present invention also relates to Use of this shaped body, which is available according to the type described above, as a semi-finished or Cladding in damp or outdoor areas, especially in the construction sector. In addition, can the shaped body according to the invention as Packaging material, flooring, in particular parquet or laminate, as stairs or decor beams. These aforementioned Uses of the molding relate preferably to the interior of vehicles, in particular of passenger vehicles preferably selected from the group: motor vehicles such as passenger cars and camping vehicles or buses, caravans, trams, Ships, railways and planes. Alternatively, the shaped body according to the invention for decorative Outdoor use or in the household and commercial sector, especially in the kitchen and plumbing be used.

The veneer strip plate according to the invention is for certain uses, in particular for use in vehicle interiors or as staircase element, coated. Preferably, the complete Top, the front and the bottom of the plate with a High-pressure laminate (HPL laminate), an endless laminate (CPL laminate) or a polyester laminate insoluble coated or encased. The respective coating is usually on a postforming system carried out.

One HPL laminate is under pressure of at least 70 bar and a temperature of about 150 ° C and a CPL laminate under pressure of a maximum of 30 bar at a temperature of about 150 ° C pressed. HPL laminates are used as single plates and CPL laminates produced in the endless production process. HPL laminates have one Thickness from 0.4mm to over 50 mm. CPL laminates can in thicknesses of 0.2 mm to a maximum of 1.2 mm.

Instead of HPL, CPL or polyester laminate, the sheath or Coating also of epoxy or melamine resins, polyurethane and Like. Be formed. Preferably, the laminate coating is top side with a highly abrasion-resistant, impact-resistant, fire-retardant as well as slip-resistant layer provided. To increase the surface stability can in the laminate or in the coating additionally a glass fiber layer be incorporated.

The The following examples are intended to explain the invention in more detail. In the compositions are all parts by weight unless otherwise stated.

A) Adhesives:

• K1: Foam-forming two-component polyurethane adhesive with a carboxylic acid-water mixture as blowing agent based on diphenylmethane-4,4'-diisocyanate (Crude MDI) and polypropylene glycols and glycerol (Macroplast UK 8526, Henkel KGaA).
• K2: Non-foaming two-component polyurethane adhesive based on diphenylmethane-4,4'-diisocyanate (crude MDI), di- and trifunctional polypropylene glycols and calcium carbonate as filler (Macroplast UK 8121 B15 , Henkel KGaA).
• K3: diphenylmethane-4,4'-diisocyanate (Crude MDI) with high oligomer content (Desmodur VKS, Bayer).
• K4: adhesive based on melamine, urea, phenol and formaldehyde (Kauratec 505, Fa. BASF)

B) Production:

To 5 kg of softwood veneer strip with the average dimensions: length 165 mm, width 20 mm and thicknesses of 0.4, 0.6 and 0.9 mm were mixed with the proportions indicated in the tables adhesive in a mixing drum. In the case of the two-component polyurethane adhesives, first metered addition of the isocyanate component took place. The mixture was then placed in three layers in a metal mold and pressed at 160 ° C. for 5 minutes at a pressure of 3 MPa. The produced plates of 6 mm thickness have a density of 650 kg / m ³ , a smooth surface and can be processed like wood, for. Sawing, planing, grinding, milling and drilling. The material can be cut threads.

C) Measurement results:

In Tables 1 to 5 are the measured elastic moduli E L and E Qu and bending strengths B L and B Qu are shown, measured 10 days after preparation of the corresponding plates.

e L and E Qu here are the moduli of elasticity along (E L) and transverse (E Qu) in MPa.

With B L and B Qu are the bending strength along (B L) and transverse (E Qu) denoted MPa.

It 3, 4, 6 and 10 parts of adhesive were used. These shares were each added to 100 parts of dried veneer strips.

Tab. 1

Tab. 2

To Tab.1 and 2:
Thick veneer strips: 0.6 mm
A comparable 6 mm thick three-layer plywood board made of melamine-formaldehyde resin has the following values:
EL: 8000 MPa, Eqm: 3000 MPa,
BL: 65 MPa, B Qu: 40 MPa

Out It is clearly evident from Tables 1 and 2 that the plate according to the invention with only 6 parts glue very high strengths and moduli of elasticity that has over the level of a comparable plywood board lie.

Tab. 3

To Tab. 3:
Adhesive amount: 6 parts to 100 parts of dried veneer strips

Especially with small veneer strip thicknesses are surprisingly high strengths and E moduli achieved.

Tab. 4

Tab. 5

To Tab. 4 and 5:
Thick veneer strips: 0.6 mm
Adhesive amount: 6 parts to 100 parts of dried veneer strips
Hydrophobing agent: Hydrowax 560 (Sassol Wax GmbH, Hamburg)
Quantity of water repellent: 1 part (calculated on solids) to 100 parts of dried veneer strips
Value determination 10 days after preparation or after 15 days reconditioning at room temperature

These two tables show that the veneer strip panels a good resistance to water exhibit. After drying almost the same strengths and Moduli as achieved before water storage, and the influence of water repellents is not significant.

Claims (14)

Process for the production of moldings based on polyurethane binders and cellulose-containing material, characterized in that a) as polyurethane binders at least one foam-forming two-component polyurethane adhesive is selected, b) the cellulose-containing material in the form of strips having a thickness of 0.3 mm 1.5 mm, preferably a thickness of 0.4 mm to 0.8 mm, a length of 80 to 300 mm, preferably a length of 100 to 250 mm, and a width of 10 to 45 mm, preferably 15 to 25 mm c) the cellulose-containing material and the polyurethane binder under a pressure of 1 × 10 ⁵ to 15 × 10 ⁶ Pa (0.1 MPa to 15 MPa), preferably from 1 × 10 ⁶ to 10 × 10 ⁶ Pa (1 MPa to 10 MPa) glued together. Method according to claim 1, characterized in that that the weight fraction of the polyurethane binder to 0.5 to 25 parts by weight, preferably 1.0 to 15 parts by weight and especially preferably 1.5 to 10 parts by weight per 100 parts by weight adjusts cellulose-containing material. Method according to claim 1 or 2, characterized that the process step (c) at a temperature of 60 to 230 ° C, preferably carried out at a temperature of 80 to 160 ° C. Method according to one of claims 1 to 3, characterized the cellulose-containing material is veneer strips selected from the group of coniferous and hardwood trees, in particular from the group the birch, poplar, pine spruce wood. Method according to one of claims 1 to 4, characterized that the polyurethane binder and / or the cellulose-containing material at least one auxiliary from the group: fillers, water repellents, release agents, Stabilizers is added, preferably as auxiliaries at least an internal release agent is added. Moldings, prepared according to at least one of claims 1 to 5. moldings according to claim 6, characterized in that it as a cube, cuboid, Plate, bar or cylinder is designed. moldings according to claim 7, characterized in that it as veneer strip plate is designed. Veneer strip plate according to claim 8, characterized from 1 to 10, preferably from 2 to 8 and especially preferred 3 to 5 layers is built up. Veneer strip board according to claim 8 or 9, characterized characterized in that the plate has a thickness of 2 to 40 mm, preferably 2 to 20 mm, in particular 2 to 10 mm. Veneer strip board according to one of claims 8 to 10, characterized in that it has a density of 300 kg / m ³ to 800 kg / m ³ , preferably from 400 kg / m ³ to 700 kg / m ³ , in particular from 450 to 600 kg / m ³ . Use of the molding after at least one the claims 6 to 11 as semi-finished or cladding in wet or outdoor areas, especially in the construction sector. Use of the molding after at least one the claims 6 to 11 for the manufacture of furniture, Kitchen countertops, floors, walls Stairs or ceilings. Use of the molding after at least one the claims 6 to 11 for the interior fittings in vehicles, in particular in passenger vehicles, preferably selected from the group: buses, ships, railways and planes as well in camping vehicles and caravans.