Method for producing wood materials, wood materials and binding agents for the production thereof

Abstract

In a first aspect, the present invention relates to a method for producing wood-based materials or materials made from cellulose-containing materials, wherein these are produced with binders or heat treatment and exhibit reduced emissions of acetic acid and other VOC compounds after heat treatment. Prior to heat treatment, a surfactant and / or an antioxidant is added to the binder and / or the cellulose-containing materials or the wood-based materials. In a further aspect, wood-based materials produced accordingly, in particular OSB boards or particleboard, but also fiberboard, are provided. Finally, binders for cellulose-containing materials and wood-based materials are described, comprising surfactants, antioxidants, protein hydroxyaldehyde resin, and glycerin.

Description

[0001] In a first aspect, the present invention relates to a method for producing wood-based materials or materials made from cellulose-containing materials, wherein these are produced with binders or heat treatment and exhibit reduced emissions of acetic acid and other VOC compounds after heat treatment. Prior to heat treatment, a surfactant and / or an antioxidant is added to the binder and / or the cellulose-containing materials or the wood-based materials. In a further aspect, wood-based materials produced accordingly, in particular OSB boards or particleboard, but also fiberboard, are provided. Finally, binders for cellulose-containing materials and wood-based materials are described, comprising surfactants, antioxidants, protein hydroxyaldehyde resin, and glycerin. Status the Technology

[0002] Binders play a crucial role in the production of wood-based composites and wood-based materials in general, as well as materials made from or containing cellulose-containing materials. The use of binders is restricted by regulations such as the VOC Directive, which aims to limit the emission of volatile organic compounds (VOCs) and highly volatile organic compounds (VVOCs). VOCs and VVOCs occur in varying chemical compositions and quantities, depending on the type and condition of the lignocellulose used, the wood species, the gluing time, the gluing conditions of the wood, and the specific cellulose-containing materials. Furthermore, binders based on aminoplasts release VOCs and VVOCs, particularly formaldehyde.The primary focus in the binder industry is on reducing formaldehyde emissions, a major representative of VVOCs. The limit value has been lowered from E1 (corresponding to 0.1 ppm) to E0.5 (corresponding to 0.06 ppm). To meet these requirements, the binder industry has developed adapted formulations for corresponding formaldehyde-based resins, such as UF (urea-formaldehyde) or MUF (melamine-urea-formaldehyde) resins. This has involved, for example, reducing the MOL ratios in the binders.

[0003] Alternatives to formaldehyde-containing resins have been developed, such as isocyanate-based binders, e.g., PMDI. However, these present other, well-known problems, including their high cost and the development of hazardous substances, e.g., in the event of a fire, due to the formation of hydrogen cyanide, among other things.

[0004] Furthermore, other binders, e.g., protein-based binders, have been developed. These are designated as E-0, meaning they do not require the addition of formaldehyde for the reaction.

[0005] To reduce the release of formaldehyde and other VVOCs and VOCs, various solutions have been proposed over the years. These typically involve adding additives to the manufacturing process to capture formaldehyde or other volatile compounds. A common method is the addition of a urea solution in the refiner to reduce formaldehyde emissions, for example, in fiberboards with UF binders. In particleboard production, a urea solution is introduced into the blender to bind formaldehyde.

[0006] Nowadays, OSB boards are primarily bonded using isocyanate-based adhesives. No binders are added to the OSB strands during manufacturing.

[0007] Various measures for reducing VOC and VVOC levels in wood-based panels are known in the literature. These include the use of various binders, including UF, MUF, and PMUF (phenol-melamine-urea-formaldehyde resin), as well as isocyanates. For example, increasing the pH value during manufacturing is proposed, as in WO 2006 / 039914 A1 or DE 10 2009 046 127 A1. EP 2 138 528 A1 suggests the use of oxidation catalysts, while DE 10 2006 020 612 A1 describes the use of various additives, alone or in combination.

[0008] However, the methods known to date for reducing VOCs and VVOCs are only partially successful. This applies in particular to minimizing the emission of acetic acid, but also, for example, furfural as a component of VOC emissions, especially during the manufacturing process. This problem occurs not only with conventional formaldehyde-containing binders, but also with isocyanate-based binders and protein binders.

[0009] As mentioned, the formation and release of VOCs and VVOCs depends on the type and condition of the lignocellulose, and thus on the growing area of ​​the individual wood species; another problem is the increasing use of recycled wood.

[0010] Pine, which is widely used in Europe, has a high acetic acid content and is commonly processed into wood-based materials. The maritime pine found in southern Europe has a 50% higher acetic acid content than the northern European pine. Spruce and beech have been described as having low VOC emissions compared to pine, while poplar shows very low values. These wood species are also used in the production of wood-based panels in Europe.

[0011] Recycled wood, which is increasingly used in the production of engineered wood panels, also has the problem that, in addition to the aforementioned wood species, it still contains binders, e.g., particleboard with UF / MUF binders, isocyanate binders in OSB, and MDF / HDF fiberboard with UF or MUF binders. These release large quantities of VOCs and VVOCs during the heat treatment for pressing the respective engineered wood panels. In 2021, approximately 50% of particleboard used in Europe was made from recycled wood, corresponding to approximately 17 million m³.

[0012] The use of recycled wood presents significant challenges for VOC scavengers, as the materials used are not defined and may exhibit additional contamination from the chemical adhesives used, as well as post-treatments of the wood-based panels, such as coatings or paints. During the pre-treatment of recycled wood, e.g., in wood washing plants, it is not possible to filter out 100% of the foreign substances.

[0013] In addition to the two problems mentioned above, another is the need for high pressing temperatures during the heat treatment of wood-based materials, specifically temperatures above 180°C, and especially 220°C and higher, which significantly increase VOC and VVOC emissions. To produce wood-based materials economically on an industrial scale, pressing factors of approximately 5.5 seconds / mm of board thickness are targeted for MDF / HDF, and pressing factors of less than 4 seconds / mm for particleboard. These speeds can only be achieved through high pressing temperatures, typically in the range of 220°C to 240°C. The disadvantage is the significantly increased emission of VOCs and VVOCs from the wood.

[0014] In recent years, alternative bio-based binders that meet industrial standards have increasingly entered the market. Various products based on protein resins have been described. These include binders with protein hydroxyaldehyde resin on a purely biogenic basis, e.g., from the company SESTEC, but also those with proteins and chemical cross-linkers, or based on proteinogenic amino acids or chemical components and protein as fillers.

[0015] It has been described that proteins can act as scavengers for volatile emissions. VOCs such as hexanal, hexanoic acid, and 1-hydroxy-2-propanone can be captured by undenatured proteins in measurable quantities, up to 40%. The simultaneous use of glycerol, which can be present in biobinders, allows for the binding of VOCs. Protein binders are described, for example, in EP 3 684 573 B1 or WO 2022 / 019790 A1. The corresponding use of glycerol, for example, as an example of the use of polyhydric alcohols, is described in WO 2021 / 101396 A1.

[0016] However, all existing solutions suffer from the problem that acetic acid, as a component of VOCs, cannot be captured by, for example, biogenic binders of the type mentioned above. Acetic acid originates from the wood itself and is released during refiner pulping or by high temperatures exceeding 180°C during the pressing process of wood-based panels. Acetic acid is also the trigger for the detection of furfural. Higher temperatures lead to an increased acetic acid content and an increase in furfural formation. Furfural is formed in an acid-catalyzed process, primarily initiated by acetic acid.

[0017] The object of the present invention is therefore to provide such processes and binders which, in particular, prevent acetic acid emissions during the production of wood-based materials and materials made from cellulose-containing materials, but also during use. Description of the invention

[0018] In a first aspect, the present application relates to a process for producing wood-based materials or materials made from cellulose-containing materials, wherein the wood-based materials or materials made from cellulose-containing materials are treated with binders under heat treatment and wherein the wood-based materials or materials made from cellulose-containing materials exhibit a reduced emission of acetic acid and other VOC compounds after heat treatment, comprising the step of i) adding surfactant and / or antioxidant to the cellulose-containing materials or the wood-based materials and / or ii) adding surfactant and / or antioxidant to the binder before heat treatment.

[0019] Acetic acid is a component of many plants and plant saps. In fact, acetic acid is often only formed in cellulose-containing materials after exposure to heat, at which point it is released into the environment along with other escaping gases. For example, in particleboard, acetic acid is emitted when the cellulose-containing materials are heated in the press to temperatures exceeding 180°C to 240°C, thus initiating the emission. During the drying process of the processed fibers in the refiner, or in the case of wood chips, an acetic acid concentrate is formed because the moisture content of the wood is minimized. The moisture from the applied binder initiates, among other things, a "vapor surge effect," and the acetic acid concentrate is partially emitted from the wood-based material. When using isocyanate-based adhesives, such as MDI, for example in OSB production, water is additionally injected to initiate the isocyanate-based curing process.A similar effect to that seen with particleboard occurs. VOC measurements during heat treatment, i.e., pressing, show disproportionately high levels of acetic acid release. These VOC measurements with disproportionately high acetic acid levels also include terpenes and aldehydes, both saturated and unsaturated.

[0020] Surprisingly, it has now been shown that the use of surfactant and / or antioxidant in the manufacturing process significantly reduces this emission of acetic acid.

[0021] This process involves adding surfactants and / or antioxidants to the cellulose-containing materials or wood-based materials. Alternatively, surfactants and / or antioxidants can be added to the binder, or in addition to it, before undergoing heat treatment.

[0022] It is assumed that an added surfactant, especially in combination with protein binders, improves the reactivity of these proteins, i.e., their scavenging properties, and thus reduces the emission of VOCs, and in particular acetic acid. The added antioxidants further reduce the formation and release of acetic acid as a component of the VOCs.

[0023] In one embodiment of the process according to the invention, the surfactant and / or antioxidants are added at least to the binder before heat treatment. Typically, the surfactant and / or antioxidant is added to the binder as a solid or in solution.

[0024] Suitable mixing methods are known to those skilled in the art.

[0025] The heat treatment is carried out according to known methods. That is, the usual pressing processes used for the production of wood-based materials, such as wood-based panels including OSB, particleboard or fiberboard, are employed.

[0026] In one embodiment, the wood-based material or the cellulose-containing material is mixed with the binder containing surfactant and / or antioxidant without further pretreatment and is heat-treated.

[0027] In this context, the term "cellulose-containing material" refers to materials containing cellulose, hemicellulose, holocellulose, or lignocellulose. Cellulose-containing materials include, among others, wood, pulp, straw, etc. For the production of wood-based materials, especially wood-based panels, the corresponding raw materials—i.e., cellulose-containing materials—are those made from wood chips, sawdust, wood strands, wood fibers, wood veneers, etc.

[0028] Unless otherwise stated, the term "binder" here refers to suitable binders for use in the wood-based materials industry or as binders for materials made from cellulose-containing substances. Well-known examples include the aforementioned formaldehyde-containing binders, such as UF, MUF, or PMUF resins. Other common binders include isocyanate-based binders, including those based on diisocyanates such as PMDI, polyurethane-based adhesives, and tannin-formaldehyde adhesives. Further suitable adhesives include protein-containing binders, as known in the prior art.

[0029] The surfactants and / or antioxidants can be introduced via the binders as described, or they can be applied directly, e.g., as an emulsion, to the cellulose-containing materials such as wood chips, wood fibers, or wood strands. Suitable timing and process steps for application or incorporation are known to those skilled in the art. In one embodiment, a mixture of surfactant and antioxidants is used in the process according to the invention.

[0030] Unless otherwise stated, the terms "surfactant" and "antioxidant" include both the singular and multiple such compounds, such as two, three, four or more compounds.

[0031] In one embodiment, a surfactant according to the invention is a non-ionic surfactant, or, when using a mixture of surfactants, at least one of these surfactants is a non-ionic surfactant. In one embodiment, the non-ionic surfactant is selected from octylphenol ethoxylates, nonylphenol ethoxylates, alkyl polyglycosides, and / or alkyl glycosides.

[0032] It was found that polysorbates, such as the Tween products, are particularly suitable. The polysorbates can be used as polysorbates 20, 21, 40, 60, 61, 65, 80, 81, 120, or mixtures thereof.

[0033] The antioxidants to be used according to the invention are not particularly restricted; suitable antioxidants are, in particular, aromatics with alkyl and hydroxy substituents. It has been found that butylhydroxyanisole and butylhydroxytoluene are particularly suitable antioxidants. These two compounds can be used alone or in combination. Both compounds are approved as food additives, E320 and E321, respectively. Butylhydroxytoluene is produced in nature by, among others, green algae and cyanobacteria and is particularly suitable for bio-binders. It has been found that in one embodiment, the proportion of surfactant in the binder is between 0.01 and 5% by mass, preferably 0.05 and 2.5%, or 0.08 and 2%, based on the solid binder. The same values ​​apply to antioxidants, i.e.,The mass fractions of the respective antioxidants range from 0.01 to 5%, preferably 0.05 to 2.5%, or 0.08 to 2.0% based on the solid binder content. The total amount of surfactant and / or antioxidants added to the binder ranges from 0.2 to 15%, or 0.5 to 10%, based on the solid binder content.

[0034] As explained, the additive can be added as a solid and / or as a corresponding solution or emulsion.

[0035] The addition of surfactant and / or antioxidants to the binders or to the cellulose-containing materials can be done separately, can be present in the binder, or can be applied to the cellulose-containing materials as a two- or multi-component product.

[0036] In one embodiment of the process according to the invention, the binder comprises protein-hydroxyaldehyde resin, wherein the mass fraction of protein is between 10 and 50%, preferably between 10 and 45%, particularly preferably between 15 and 40%, and especially between 20 and 40%, based on the solid binder. In particular, it has been shown that with commercially available protein binders, the addition of additional proteins reduces the emission of, in particular, acetic acid and other VOC components.

[0037] In a further embodiment of the process according to the invention, glycerin is added to the binder, which comprises protein-hydroxyaldehyde resin. In one embodiment, this glycerin comprises a mass fraction of 20 to 50%, preferably 25 to 45%, particularly preferably 30 to 45%, and especially 30 to 40%, based on the solid binder. Compared to commercially available binders to which glycerin has already been added, it has been shown that glycerin, as an example of a polyhydric alcohol, improves the desired properties of reducing the emission of acetic acid and other VOCs.

[0038] When using binders other than protein-containing binders, in particular protein-containing binders additionally containing glycerin, the addition of surfactant is not strictly necessary. Rather, according to the invention, with non-protein binders, such as formaldehyde-containing binders including UF binders, MUF binders, PMUF binders or isocyanate-based binders, only the antioxidant agents according to the invention are added.

[0039] In one embodiment, the inventive method comprises heat treatment at a pressing temperature above 180°C, particularly in the range of 220°C to 240°C. The pressing process of wood-based materials, especially wood-based panels such as particleboard, plywood, fiberboard, and OSB panels, is carried out according to known methods.

[0040] The further processing steps of the wood materials to obtain corresponding wood-based panels of the aforementioned type are also known to the expert.

[0041] In a further aspect, the present invention relates to wood-based materials or materials made from cellulose-containing materials, obtainable by the method according to the invention. In particular, these wood-based materials are wood-based panels. These include particleboard, fiberboard such as MDF and HDF panels, as well as OSB panels and plywood panels. Specifically, the wood-based panels are fiberboards, namely MDF or HDF panels. Furthermore, suitable wood-based materials include OSB panels (single-layer or multi-layer) and particleboard (single-layer or multi-layer, such as three-layer).

[0042] In one embodiment, the wood-based panel available according to the invention is an OSB panel or a particleboard, wherein a surfactant and an antioxidant are added. In another embodiment, the wood-based panel is a fiberboard, e.g., a fiberboard with a formaldehyde-containing binder, wherein at least one antioxidant, preferably a combination of two antioxidants, such as a combination of dihydroxyanisole and butylhydroxytoluene, is added to the binder. In one embodiment, no surfactant is added to the fiberboard or its binders.

[0043] In another aspect, binders for cellulose-containing materials and wood-based materials are provided. These binders according to the invention comprise a surfactant, as defined herein, antioxidants, as defined herein, a protein hydroxyaldehyde resin, and optionally glycerin. Preferably, the protein content in the binders, based on the solids content of the binder, is in the range of 10 to 50%, the glycerin content is in the range of 20 to 40%, and the total surfactant and / or antioxidant content is in the range of 0.5 to 10%, each based on the solids content of the binder.

[0044] In one embodiment, the binder according to the invention comprises a protein content of over 30 to 45%, a glycerin content in the range of 20 to 40%, and a surfactant and / or antioxidant content of 0.5 to 2% each, based on the solid binder.

[0045] Finally, the use of a binder according to the invention and / or of surfactants and / or antioxidants, as defined herein, for the production of a wood-based material with reduced emissions of acetic acid and other VOC compounds is provided. In particular, this involves the use of protein-hydroxyaldehyde resin-based binders or the use of surfactants and / or antioxidants in protein-hydroxyaldehyde-based binders for the production of the wood-based materials according to the invention.

[0046] The invention is explained in more detail below using examples, without limiting its scope: The investigations were carried out on the basis of the following standards: Table 1: All test results according to: DIN ISO 16000-6:2022-03, DIN EN ISO 16000-9:2008-04 and DIN EN ISO16000-11:2006-06 Chamber test DIN EN 16516 VOC according to DIN 16516, GC / MS Formaldehyde / aldehyde / acetone according to DIN EN 16516, HPLC Evaluation according to AgBB 2018 NIK values ​​(lowest concentration of interest)

[0047] VOC measurements were carried out over periods of 3 days and 28 days in accordance with EN ISO 16000-9.

[0048] A bio-based binder from SESTEC Polska Sp.zoo was used (SESTEC Binder W 351 A?). This binder typically contains 20% protein and 25% glycerin.

[0049] In the examples according to the invention, the proportions of proteins were increased to 40% and of glycerin to 30%, and the water content was reduced accordingly; the solids content of the binder was therefore 63%.

[0050] The binder is a one-component resin without a hardener.

[0051] As shown in the example below, this bio-binder was added to the liquid resin in a quantity of 0.5 per 1 kg each of polyoxyethylene sorbitan monooleate (polysorbate 80 or Tween 80), butylhydroxyanisole, and butylhydroxytoluene. With a binder content of 63%, this corresponds to 0.9% of the respective single component in the solid resin. Hereinafter, these three components will be referred to as the additive PBP.

[0052] The plates used had the following properties: Table 2: MDF / HDF Chipboard (3-layer) OSB (single layer) - Panel thickness 6 mm 16 mm 12 mm - Specific gravity 780 kg / m3 640 kg / m3 620 kg / m3 - Moisture before gluing / 3,5 % 4,0 % - Gluing by means of blow line Blender Blender - Moisture after gluing 9% after drying 11 % 12% - Glue content 11 % Decks 9% / / Core 7% 9 % - Pressing temperature 230°C 220°C 220 °C - Pressing time (laboratory) 8 sec / mm 8 sec / mm 8 sec / mm

[0053] The particleboard in question is made from recycled wood of class A2, meaning glued, coated, and lacquered reclaimed wood without halogenated organic compounds in the coating and without PVC content. During production, care was taken to ensure that not only dust but also visible particles of MDF and foreign materials (paper coatings, melamine coatings, and the finest plastic particles from furniture edges) were processed. The raw materials used are standard, commercially available components.

[0054] The production of the corresponding plates was carried out using standard procedures; the relevant parameters are shown in the table above.

[0055] The manufactured panels were measured according to the aforementioned standards. The reference example with urea-formaldehyde resin and hydrowax is a UF resin from BASF, Kraurit Adhesive 333; the hydrowax used (proportion: 1.5% on oven-dried wood) is Aquaveg 50A-1208-001 (Bio Hydrowax).

[0056] The following values ​​are presented: Summary of measurements of all emissions for MDF / HDF (pure pine) 6 mm thick Table 3: reference (Standard) Bio-binder Organic binders Organic binders UF resin + Hydrowax 20% Protein + 25% Glycerin + Hydrowax 40% Protein + 30% Glycerin + Hydrowax 40% Protein + 30% Glycerin + PBB + Hydrowax Acids 775 624 580 127 Aldehydes 5882 1260 980 451 alcohols 444 128 96 7 Esters, Ethers, Ketones 1178 628 590 417 aromatic HC 883 682 434 218 saturated HC 337 311 278 53 unsaturated HC 8546 5166 4825 4613 Terpenes 1373 1238 1215 1114 r Value (3 days) 15391 11037 9783 3962 r Value (28 days) 14376 8946 6940 2712

[0057] The acids are predominantly acetic acid. Acetic acid makes up the largest proportion at approximately 85%, followed by formic acid (10%) and approximately 5% furfural, formed from acetic acid.

[0058] The measurements of all emissions from particleboard (recycled wood) 16 mm thick are shown in the following table: Table 4: reference (Standard) Bio-binder Organic binders Organic binders UF resin + Hydrowax 20% Protein + 25% Glycerin + Hydrowax 40% Protein + 30% Glycerin + Hydrowax 40% Protein + 30% Glycerin + PBB + Hydrowax Total VVOC ( <C6) 165 119 <1 <1 Total VOC (C6-C16) 385 93 82 71 Total SVOC (C16-C22) <1 <1 <1 <1 TVOC 385 93 82 71 Toluene equivalent 101 45 39 29 formaldehyde 0.052 ppm 0.008 ppm 0.007 ppm 0.007 ppm

[0059] Finally, the emission measurements for OSB (pure pine) 12 mm thick are shown in the following table: Table 5: reference (Standard) Bio-binder Organic binders Organic binders UF resin + Hydrowax 20% Protein + 25% Glycerin + Hydrowax 40% Protein + 30% Glycerin + Hydrowax 40% Protein + 30% Glycerin + PBB + Hydrowax Total VVOC ( <C6) 165 102 <1 <1 Total VOC (C6-C16) 2740 1876 1585 682 Total SVOC (C16-C22) 112 <1 <1 <1 TVOC 2852 1876 1585 682 Toluene equivalent 1316 805 655 121 formaldehyde 0.082 ppm 0.0074 ppm 0.0069 ppm 0.0064 ppm

[0060] The difference here is a board with MDI as a binder, in this case Huntsman-I-BOND MDF EM 4330 MDI resin with hydrowax, as already mentioned above.

[0061] As the measurements clearly show, a significant reduction in acetic acid and other VOC emissions can be observed. This was particularly evident with the binders according to the invention with the addition of the PBB additive and increased protein and glycerin contents.

[0062] The following are the measurements in which only the antioxidants according to the invention, without surfactant, were added to the binder. Table 6: The measurements of all emissions from particleboard (recycled wood) 16 mm thick are shown in the following table: Reference UF + Hydrowax (1.5%) (Standard) UF + Hydrowax (1.5%) + BB Total VVOC ( <C6 ) 165 85 Total VOC (C6-C16) 385 74 Total SVOC (C16-C22) <1 <1 TVOC C6-C16 385 74 Toluene equivalent 101 29 formaldehyde 0.052 ppm 0.05 ppm

Claims

1. A method for producing wood-based materials or materials made from cellulose-containing materials, wherein the wood-based materials or materials made from cellulose-containing materials are treated with binders under heat treatment and wherein the wood-based materials or materials made from cellulose-containing materials exhibit reduced emission of acetic acid and other VOC compounds after heat treatment, comprising the step of i) adding surfactant and / or antioxidant to the cellulose-containing materials or the wood-based materials and / or ii) adding surfactant and / or antioxidant to the binder before heat treatment.

2. The method for producing wood-based materials or materials from cellulose-containing materials according to claim 1, wherein the addition of surfactant and / or antioxidant is made at least to the binder.

3. The method for producing wood-based materials or materials from cellulose-containing materials according to claim 1 or 2, wherein the wood-based material or cellulose-containing material is mixed with the binder and heat-treated without pretreatment.

4. The method for producing wood-based materials or materials from cellulose-containing materials according to any of the preceding claims, wherein a mixture of surfactant and antioxidant is added.

5. The method for producing wood-based materials or materials from cellulose-containing materials according to any of the preceding claims, wherein the surfactant is a non-ionic surfactant or the surfactants comprise at least one non-ionic surfactant, in particular wherein the non-ionic surfactant is selected from octylphenol ethoxylates, nonylphenol ethoxylates, alkyl polyglycosides and / or alkyl glycosides, in particular polysorbate.

6. The method for producing wood-based materials or materials from cellulose-containing materials according to any of the preceding claims, wherein the antioxidant is selected from alkyl hydroxyaromatics, in particular butylhydroxyanisole and / or butylhydroxytoluene.

7. The method for producing wood-based materials or materials from cellulose-containing materials according to any one of claims 1 to 3 or 6, wherein the binder is selected from UF / MUF, PMUF, protein binder or isocyanate-based binders.

8. The process for producing wood-based materials or materials from cellulose-containing materials according to one of the preceding claims, wherein the proportion of surfactant and / or antioxidant is added in a mass fraction of 0.01 to 5%, preferably 0.05 to 2.5%, such as 0.08 to 2.0% based on solid binder.

9. The process for producing wood-based materials or materials from cellulose-containing materials according to any of the preceding claims, wherein i) the binder is a protein hydroxyaldehyde resin, wherein the mass fraction of protein is between 10 and 50%, preferably 10 and 45%, particularly preferably over 15 and 40%, and in particular over 20 and 40%, based on the solid binder, and / or ii) wherein glycerin is further added to the binder, such as protein hydroxyaldehyde resin, in particular with a mass fraction of glycerin between 20 and 50%, preferably 25 and 45%, and in particular 30 and 45%, based on the solid binder.

10. The method for producing wood-based materials or materials from cellulose-containing materials according to any of the preceding claims, wherein the addition of surfactant and / or antioxidant is applied by emulsion to the cellulose-containing materials, such as wood chips, wood fibers or wood strands, as two or more components.

11. The method for producing wood-based materials or materials made from cellulose-containing materials according to one of the preceding claims, wherein the heat treatment involves a pressing temperature of over 180°C, in particular in the range of 220 to 240°C.

12. Wood-based material or material made from cellulose-containing materials obtainable by a method according to any one of claims 1 to 11.

13. Wood-based material according to claim 12, wherein this is an OSB board or a particleboard and wherein surfactant and antioxidant have been added during its manufacture or wherein this is a fiberboard and this has at least antioxidant, optionally without surfactant.

14. Binder for cellulose-containing materials and wood-based materials, comprising: a. a surfactant as defined in any one of claims 1 to 11; b. an antioxidant as defined in any one of claims 1 to 13; c. a protein hydroxyaldehyde resin as defined in any one of claims 1 to 11; optionally d. glycerin, wherein preferably the proportion of proteins is in the range of 10 to 50%, the proportion of glycerin is in the range of 20% to 40%, and the proportion of surfactant and / or antioxidant is in the range of 0.5 to 10%, based on the solids content of the binder.

15. Binder according to claim 18 comprising a protein content of over 30 to 45%; a glycerin content of 30 to 40%; and a surfactant and / or antioxidant content of 0.5 to 2% based on the solid binder.

Images