BIOLOGICAL PROTECTION FOR WOOD

Abstract

The invention relates to a method for producing a coated wooden component that has biological protection against infestation by wood-destroying and / or wood-staining fungi, based on impregnation or pretreatment with a pre-culture and / or with spores of a fungus, in particular of the genus Trichoderma, that acts antagonistically towards wood-destroying and / or wood-staining microorganisms. The invention further relates to a wooden component produced by the method and its use as a building material in building construction, particularly in exterior applications.

Description

[0001] The invention relates to a method for producing a coated wooden component that has biological protection against infestation by wood-destroying fungi. The invention further relates to a wooden component produced by the method and its use as a building material in building construction, particularly in outdoor areas.

[0002] Wood is used as a building material both indoors and outdoors. Because it is a natural product, it can be destroyed by environmental influences such as light, water, and organisms exposed to the elements. Prolonged exposure to moisture above 20% can lead to infestation by wood-destroying fungi. If the wood is destroyed, not only its appearance but also its structural stability is negatively impacted. Therefore, it is fundamentally important to protect wood from long-term moisture exposure through structural measures (structural wood protection). Physical protection is also available through coatings that have the ability to reduce moisture absorption. However, structural wood protection is not possible for all building components, such as those in a house. Balconies, formwork, windows, doors, and fences are constantly exposed to the elements and therefore to moisture.Physical protection provided by coatings has also been limited so far. As a result, algae and microorganisms (bacteria and fungi) are increasingly colonizing such building components.

[0003] Against this background, it is known and common practice to ensure protection against microorganisms through coating systems (impregnation, protective varnishes, etc.) containing biocides. The technologies used to date are based on conventional active ingredients, primarily propiconazole, borates, and 3-iodopropargyl-N-butylcarbamate (IPBC). However, chemical wood protection is usually temporary and not permanent, as the biocides used diffuse out of the coating or are washed out due to their low molecular weight. As a result, the purely organic chemical active ingredients are often also degraded. This reduces their effectiveness, and the active ingredients used enter the environment. Since biocides are usually ecotoxicologically harmful substances and their entry into the environment should be avoided as far as possible, legal regulations often exist.Their use is becoming increasingly strictly regulated, and many products in use have already been banned. This creates a significant need for alternative solutions.

[0004] In principle, the use of traditional biocides can be avoided by using biologically active wood protection. Such "biological wood protection" through the use of microorganisms (especially antagonistic fungi or bacteria) and enzymes can be viewed as a parallel technology to the previously known wood protection options, which include, firstly, constructive wood protection through building measures; secondly, physical wood protection, e.g., against radiation and moisture through coating or varnishing; and thirdly, chemical wood protection using biocides. Biological wood protection primarily involves the use of living organisms (antagonistic microorganisms) or enzymes, but also includes the use of other active ingredients of biogenic origin. Such active ingredients are of natural origin and are in contrast to synthetically produced, traditional biocides. The active ingredients can also be used in combination with so-calledBoosters are used, i.e. substances to reduce the required concentration of active ingredient.

[0005] Living organisms of the genera Trichoderma, Gliocladium, Bacillus, Pseudomonas, and Streptomyces, among others, have potential for use in wood protection. Their effects are well known in plant protection. Their mechanisms of action are based, on the one hand, on their competition with wood-destroying or wood-discoloring organisms for available nutrients, and, on the other hand, on their production and excretion of various biochemical substances effective against pests. Antagonists interact with specific target organisms.

[0006] Of great interest are microorganisms (fungi and / or bacteria) that exhibit a broad spectrum of activity against wood-destroying and / or wood-discoloring fungi. In addition to the direct use of living organisms, these microorganisms can also be used to produce compounds that are then used in wood preservation like synthetically produced biocides.

[0007] AT 397 811 B and DE 3 600 394 A1 describe certain fungi of the genus Trichoderma and their application in biological wood preservation. The disadvantages of the methods presented therein are that the fungi must be incubated on the treated object for days to weeks after treatment (AT 397 811 B), or the fungus is used only for control purposes, not as a preventative measure, and the fungus dies after the harmful fungus has been destroyed (DE 3 600 394 A1). Furthermore, the microorganisms used can cause discoloration of the surface.

[0008] The review articles Teacä et al. (2019), BioResources 14(2), 4873-4901 and P. Susi et al. (2011), J. Environmental Management 92, 1681-1689 provide an overview of the previous use of fungal spores, including fungi from the genus Trichoderma, in biological wood protection.

[0009] WO 93 / 08694 A1 discloses the use of certain Trichoderma strains in spore suspensions intended for use as wood and plant protection agents. Spray and dip applications, as well as a preventative treatment of wood, are described.

[0010] The article HL Brown, A. Bruce (1999), Int. Biodeterioration & Biodegradation 44, 219-233 discloses a wood treatment with Trichoderma spores, which under certain conditions is intended to serve as an alternative to chemical protection measures.

[0011] EP 3 262 938 A2 concerns the subsequent treatment of infested wood by introducing an antagonistic fungus through a borehole.

[0012] US 2002 / 096273 A1 describes the use of Ophiosomata fungal spores in spore suspensions intended for use as wood preservatives against fungal infestation. WO 93 / 01923 A1 describes the use of Gliocladium fungal spores in spore suspensions intended for use as wood preservatives against fungal infestation. CN 114 540 201 A concerns the use of a specific, new Trichoderma strain (virens NY45 CGMCC No. 40004) for treating wood against infestation.

[0013] WO 2021 / 060978 A1 discloses a wood preservative coating containing fungal spores that secrete surface-active substances to impart good physical properties to the coating and improve its adhesion to the substrate surface.

[0014] The object of the invention is to provide a practical method for producing a wooden component that can be used as a building material, which has physical protection against moisture and radiation by a coating and biological protection against infestation by wood-destroying and / or wood-discoloring fungi.

[0015] Against this background, the invention proposes a method for producing a wooden component coated on at least one surface, which has biological protection against infestation by wood-destroying and / or wood-discoloring fungi.

[0016] The method comprises impregnating the wooden component by applying an impregnating agent to the surface, followed by applying a further coating agent different from the impregnating agent to the impregnated surface to obtain a top coat. Preferably, at least two further layers are applied in the form of an intermediate layer and subsequently the top coat, with the coating agent used to apply the intermediate layer being different from both the coating agent used to apply the top coat and the impregnating agent.

[0017] According to the invention, it is provided that the impregnating agent is mixed with a pre-culture of and / or with spores of a fungus that is antagonistic to wood-destroying and / or wood-discoloring microorganisms, or that at least the surface of the wooden component to be coated is immersed in a liquid medium that is mixed with a pre-culture and / or with spores of an antagonistic fungus before the application of the impregnating agent.

[0018] The antagonistic fungus can in particular be a fungus of the genus Trichoderma. Preferred examples include a fungus of the genus Trichoderma with the scientific name Trichoderma harzianum, which was deposited on April 17, 2024 by Holzforschung Austria - Austrian Society for Wood Research, Franz-Grill-Str. 7, 1030 Vienna, Austria and ADLER-Werk Lackfabrik Johann Berghofer GmbH & Co. KG, Bergwerkstr. 22, 6130 Schwaz, Austria with the Leibniz Institute DSMZ-German Collection of Microorganisms and Cell Cultures GmbH (depositor's reference: HFA 335) and received the accession number DSM 34998, and a fungus of the genus Trichoderma with the scientific name Trichoderma virens, which was deposited on April 17, 2024 by Holzforschung Austria - Austrian Society for Wood Research, Franz-Grill-Str. 7, 1030 Vienna, Austria and ADLER-Werk Lackfabrik Johann Berghofer GmbH & Co. KG, Bergwerkstr.22, 6130 Schwaz, Austria at the Leibniz Institute DSMZ- German Collection of Microorganisms and Cell Cultures GmbH (depositor’s reference number: HFA 347) and received the accession number DSM 35005.

[0019] Both of these fungi can be propagated in malt extract agar (MEA; 12.75 g / l malt extract; 10.78 g / l peptone; 2.35 g / l glycerol; 2.75 g / l dextrin; 5 g / l agar) as a nutrient medium (pH 4.7). The incubation period is 5 days for HFA 335 and 7 days for HFA 347 at 22°C.

[0020] A combination of these fungi can also be used in one embodiment of the invention.

[0021] Experimentally, it has been shown that Tr. harzianum (HFA 335) is particularly effective against wood-destroying fungi, and that Tr. virens (HFA 347) is particularly effective against wood-discoloring fungi.

[0022] The impregnating agent containing the preculture and / or spores can be prepared by adding a liquid medium containing the preculture and / or spores to an existing impregnating agent. For example, it can be a spore suspension.

[0023] The impregnating agent may contain binders (e.g., alkyd, polyurethane, or acrylic resin) and additives. These include, for example, wetting and dispersing agents such as alkali metal and ammonium polyphosphates or alkali metal and ammonium salts of polyacrylic and polymaleic acids. The additives also include, for example, cosolvents (such as glycol ethers), defoamers, light stabilizers, hydrophobic agents, thickeners (such as cellulose derivatives, sodium polyacrylates, or associative styrene-maleic anhydride polymers or hydrophobically modified polyurethane, or inorganic systems based on hectorite or bentonite), or even fibers.

[0024] In one embodiment, the impregnating agent contains conventional chemical in-can preservatives. In the context of the present invention, these include storage preservatives within the meaning of Regulation (EU) No. 528 / 2012, Main Group 2, Product Type 6. Examples include isothiazolinones, aldehyde-containing components, aldehyde-releasing components, guanidines, sulfones, thiocyanates, pyrithiones, biocidal polypeptides, azoles, carbamates, glyphosates, sulfonamides, and antimicrobial metals, especially silver, and their salts. Preferably, the impregnating agent in the context of the present invention can contain as in-can preservative one or more substances selected from 1,2-benzisothiazol-3(2H)-one (BIT, CAS No. 2634-33-5), 2-methyl-2H-isothiazol-3-one (MIT, CAS No. 2682-20-4), 2-octyl-2H-isothiazol-3-one (OIT, CAS No. 26530-20-1), 5-chloro-2-methyl-2H-isothiazol-3-one (CIT, CAS No. 26172-55-4), bronopol (CAS No. 52-51-7), or sodium pyrithione (CAS No.3811-73-2). Preferred concentration ranges for in-can preservatives are between 0.1 ppm and 200 ppm. Experiments have shown that such in-can preservation of the impregnating agent does not adversely affect the pre-culture or spores, or at least does not significantly so. The possibility of using in-can preservation is important for the implementation of a product with the shelf life required for open sale.

[0025] The impregnating agent can be applied using all common application techniques. Examples include spraying, rolling, brushing, dipping, flow coating, and pressure impregnation. The same applies to possible intermediate and top coats.

[0026] The immersion time of the wooden component in the liquid medium, if immersion occurs, is preferably between 30 seconds and 5 minutes, more preferably between 1 and 3 minutes. This time has been experimentally proven to be sufficient and is sufficiently short for a cost-effective real-world application.

[0027] The coating structure can be transparent, translucent, or opaquely pigmented. For a translucent or opaque embodiment, one or more of the additional coating agents can contain pigments or fillers. Examples include titanium dioxide, iron oxides, carbon black, phthalocyanine pigments, diketopyrrolopyrrole pigment (DPP), silicates such as kaolin, talc, mica, alkaline earth carbonates such as calcium carbonate, and aluminosilicates such as feldspar.

[0028] The coating agent for obtaining the top layer and, if such a layer is to be applied, the coating agent for obtaining the intermediate layer are preferably free from the preculture or spores of the fungus and preferably generally free from cells of a fungus.

[0029] The coating materials used to obtain the topcoat and, if present, the intermediate coat can be paint systems. Examples include both physically curing paints, such as dispersion paints, and chemically curing or radiation-curing paints, such as polyester, alkyd, epoxy, polyurethane, acrylic, or silicone resin paints.

[0030] In one embodiment, the coating agent for obtaining the top layer is a varnish with a water-based solvent. In one embodiment, the coating agent for obtaining the top layer is a varnish with an organic solvent. In one embodiment, the coating agent for obtaining the top layer is a solvent-free varnish. In one embodiment, the coating agent for obtaining the top layer is a powder coating.

[0031] The wood to be treated or coated is preferably free of harmful fungi before the application of the process. In other words, the process is preferably a preventative method to protect the wooden component from fungal infestation.

[0032] The antagonistic fungi are preferably selected so that they do not cause discoloration of the wood. The impregnating agent is preferably colorless or transparent.

[0033] The wooden component according to the invention can be constructed from solid wood, solid wood materials (such as glued laminated timber or laminated parts), or even from particleboard and wood fiber materials. In addition to natural wood such as spruce, pine, oak, etc., modified wood (e.g., thermally or chemically treated) or other wood materials can also be used.

[0034] The invention further relates to a wooden component produced by the method with a multi-layer coating and its use as a building material in window, door, terrace, balcony and structural building construction (e.g. facades, ceilings, roofs) and timber engineering (e.g. halls, bridges, towers), in particular for outdoor use.

[0035] Finally, the invention relates to fungi of the genus Trichoderma, namely on the one hand the fungus Trichoderma harzianum (HFA 335) described in more detail above, and on the other hand the fungus Trichoderma virens (HFA 347) described in more detail above, or spores thereof.

[0036] The following examples and experiments demonstrate the effects of the invention and reveal further details. The figures show: Figure 1: Samples from Example 1 after the blue stain test. Figure 2: Samples from Example 3 after the blue stain test. Figure 3: Samples from Example 3 in the test vessels immediately before removal from the fungal test, each with 6 parallel samples divided into 2 test vessels. Figure 4: Samples from Example 4a after the blue stain test and immersion of the samples in a mixed suspension of Tr. harzianum (HFA 335) and Tr. virens (HFA 347). Figure 5: Outdoor exposure of the Trichoderma-treated samples from Example 4b in a 3- or 4-layer system. Figure 6: Samples from Example 4b in a 3-layer system before and after outdoor exposure. Figure 7: Samples from Example 4b in a 4-layer system before and after outdoor exposure. Figure 8: Development of the surface blue staining of the samples from Example 4b with a 3-layer structure over time. Figure 9: Development of the surface blue staining of the samples from Example 4b with a 4-layer structure over time. Example 1 (Efficacy of selected Trichoderma strains):

[0037] In the present example, a series of experiments was conducted in which Trichoderma was cultivated directly on wood, with pre-culture times of 1, 3, 6 and 8 weeks.

[0038] As the results listed in Table 1 show, all samples pretreated with Tr. harzianum HFA 335 or Tr. virens HFA 347 by direct growth on wood showed only slight blue staining after the blue staining test with Aureobasidium pullulans and Sydowia polyspora (5 max - poor, 0 min - optimal). The mean blue staining degrees ranged between 0.2 and 0.8, even with the shortest preculture variant of 1 week. Extending the preculture time to 8 weeks produced equivalent results. No significant difference was observed between the two Trichoderma strains regarding the degree of blue staining. Table 1 Degrees of blueing after x weeks of preculture on wood 1 week 3 weeks 6 weeks 8 weeks HFA 335 HFA 347 HFA 335 HFA 347 HFA 335 HFA 347 HFA 335 HFA 347 Controls 1,0 0,0 0,5 1,0 1,0 0,5 1,0 0,0 3,0 0,5 0,5 1,0 0,0 1,0 1,0 0,5 0,5 3,0 1,0 0,0 0,0 0,0 1,0 0,5 0,0 0,0 3,0 0,5 0,0 0,0 0,0 1,0 0,0 0,5 0,0 3,0 1,0 0,0 0,5 0,5 1,0 1,0 0,0 1,0 3,0 1,0 0,5 0,0 0,0 0,0 1,0 0,5 0,0 3,0 Mean: 0,8 0,2 0,3 0,3 0,8 0,7 0,4 0,3 3,0

[0039] Figure 1 shows the samples after the blue stain test. The left shows the samples after pretreatment with Tr. harzianum (HFA 335). The middle shows the samples after pretreatment for 1, 3, 6, and 8 weeks with Tr. virens (HFA 347) directly on wood. The right shows untreated controls.

[0040] Table 2 shows the mass losses in % of the samples pretreated with Tr. harzianum (HFA 335) and Tr. virens (HFA 347) by direct growth on wood after 12 weeks of fungal testing with Gloeophyllum trabeum and Rhodonia placenta. Table 2 Mass loss after x weeks of pre-growth on wood 1 week 3 weeks 6 weeks 8 weeks HFA 335 HFA 347 HFA 335 HFA 347 HFA 335 HFA 347 HFA 335 HFA 347 Gloeophyllum trabeum (HFA 53) 17,7 35,3 2,0 15,0 52,1 51,3 28,2 1,0 59,4 16,2 2,0 30,2 45,2 28,5 9,8 40,1 0,7 6,1 8,8 18,4 49,3 10,9 1,8 9,9 1,3 51,8 15,0 11,7 48,8 37,6 60,3 65,5 34,5 16,3 8,0 12,7 5,4 23,0 16,8 11,3 52,1 9,2 26,0 15,8 1,1 23,1 8,0 27,0 MW: 27,6 22,5 10,3 17,3 33,6 29,1 20,8 25,8 Rhodonia placenta (HFA 58) 1,8 1,8 8,4 1,4 1,61 0,9 1,7 1,5 1,5 1,7 3,6 2,1 1,66 1,2 1,2 1,4 1,7 1,8 6,1 1,4 2,23 1,0 1,3 1,8 2,4 1,8 0,9 0,8 1,41 1,0 49,0 1,4 2,4 1,7 0,0 1,0 1,43 1,6 49,7 1,3 2,1 1,9 1,3 1,3 1,36 1,2 4,7 2,0 MW: 2,0 1,8 3,4 1,3 1,6 1,1 18,0 1,6

[0041] As can be seen from the table, pre-growth with Tr. virens (HFA 347) prevented wood degradation by Rhodonia placenta during all pre-growth periods examined. This was not the case for pre-growth with Tr. harzianum (HFA 335) for all periods; after both 3 and 8 weeks of pre-growth, three samples each showed mass losses of > 3.0%, and in two cases (8 weeks of pre-growth), mass losses of almost 50% were even observed, thus providing insufficient protection. It also shows that Gloeophyllum trabeum is the wood-destroying fungus more resistant to the antagonists. Thus, after pre-treatment with direct growth, mean mass losses of > 3.0% were observed in almost all samples. Example 2 (effectiveness despite preservation):

[0042] To investigate whether an in-can preservative with fungicidal and bactericidal activity contained in coating products could inhibit the activity of the Trichoderma strains, the two Trichoderma strains mentioned above were pre-cultivated on agar culture media to obtain spore suspensions and in liquid media. The following coating products were formulated. Table 3: Coating products product Description 36150-0032-01 without in-can preservation, without biocides 36150-0032-02 Standard product (can preservative, 0.4% tebuconazole, 0.8% IPBC) 36150-0032-03 with in-can preservation, without biocides

[0043] 10% of the filtered Trichoderma liquid culture and the spore suspensions were added to each of these coating products, and 0.5 ml of each was plated onto MEA culture media (3 replicates each). The spore suspensions could be incorporated into the respective products without any discernible changes; however, upon addition of the liquid media, precipitation occurred immediately in all products, possibly due to the low pH of the liquid culture. This means for subsequent experiments in the laboratory and field that the spore suspension can be incorporated into the impregnation, thus enabling a 3-layer structure. The liquid medium, however, must be applied to wood in a separate step—at least for the time being—and thus requires a 4-layer structure. As can be seen from Table 4, in-pot preservation had no effect on the growth of the two Trichoderma strains used. Table 4: Results of the study on the survival and growth capacity of Tr. harzianum (HFA 335) and Tr. virens (HFA 347) in 5 coating products (+ Tr. growth; - no Tr. growth) product Liquid culture Spore suspension Control without Tr. HFA 335 HFA 347 HFA 335 HFA 347 36150-0032-01 + + + + - 36150-0032-02 - - - - - 36150-0032-03 + + + + - Control (without product) + + + + -

[0044] An in-can preservative with fungicidal and bactericidal activity contained in coating products does not inhibit the activity of Trichoderma strains. Therefore, the implementation of an impregnating agent containing an in-can preservative is possible to ensure the necessary product shelf life. Example 3 (Effectiveness despite short immersion time):

[0045] Experiments were conducted with pre-culture of the Trichoderma strains in liquid medium (10% each of the filtered Trichoderma liquid culture and the spore suspensions were added to the impregnation) and varying the immersion times (2 minutes, 30 minutes, 60 minutes, and 240 minutes). The immersed wood samples were then exposed to wood-discoloring and wood-destroying fungi.

[0046] Table 5 shows degrees of blueing (5 max - poor, 0 min - optimal) of the samples pretreated with Tr. harzianum (HFA 335) and Tr. virens (HFA 347) by immersion in liquid culture for different lengths of time after 6 weeks of fungal testing with Aureobasidium pullulans and Sydowia polyspora. Table 5: Degrees of blueing after x minutes of diving time 2 minutes 30 minutes 60 minutes 240 minutes HFA 335 HFA 347 HFA 335 HFA 347 HFA 335 HFA 347 HFA 335 HFA 347 Controls 3,0 0,0 1,5 0,0 0,5 0,0 0,5 0,0 3,0 3,0 0,0 1,5 0,0 2,0 0,0 1,5 1,0 3,0 3,0 0,0 2,0 0,0 1,5 0,0 1,5 0,0 3,0 2,0 0,0 1,5 0,0 2,0 0,0 2,5 0,0 3,0 2,5 0,0 0,5 0,0 1,5 0,0 1,0 0,0 3,0 2,5 0,0 1,0 0,0 2,0 0,0 1,5 0,0 3,0 Mean: 2,7 0,0 1,3 0,0 1,6 0,0 1,4 0,2 3,0

[0047] As the results recorded in Table 5 show, when the wood samples were pretreated by immersing them in a liquid culture of Tr. virens (HFA 347), blue stain-free surfaces were achieved at all immersion times tested; even an immersion time of 2 minutes was sufficient. Only one sample, immersed for 240 minutes, showed slight blue stain growth. When the samples were immersed in a liquid culture of Tr. harzianum (HFA 335), a close examination of the four sample surfaces revealed that none of the samples was completely free of blue stain.

[0048] Figure 2 shows the samples after the blue stain test. On the left are the samples after pretreatment with Tr. harzianum (HFA 335). In the middle are the samples after pretreatment with Tr. virens (HFA 347) after 2, 30, 60, and 240 minutes of immersion. On the right are untreated controls.

[0049] As in Figure 2However, despite some surfaces receiving a rating of 3.0, none of the surfaces exhibited such obvious, severe blueing as the untreated controls. With an immersion time of 2 minutes, the surfaces were rated on average with a score of 2.7, corresponding to severe blueing. After immersion times of 30, 60, and 240 minutes, significantly less blueing was observed, although extending the immersion time from 30 to 240 minutes did not result in any reduction in the blueing.

[0050] Table 6 shows the mass losses in liquid culture of the samples pretreated with Tr. harzianum (HFA 335) and Tr. virens (HFA 347) at different immersion times after the test with wood-destroying fungi (Gloeophyllum trabeum and Rhodonia placenta). Table 6: Mass loss after x minutes of diving time 2 minutes 30 minutes 60 minutes 240 minutes HFA 335 HFA 347 HFA 335 HFA 347 HFA 335 HFA 347 HFA 335 HFA 347 Gloeophyllum trabeum (HFA 53) 51,5 34,7 1,4 0,7 0,9 1,2 0,2 13,1 18,0 59,8 0,7 0,7 1,3 6,4 45,0 12,9 61,6 38,0 1,6 1,1 24,6 37,4 10,3 54,6 1,3 49,4 1,3 42,7 1,2 52,8 1,3 7,7 15,1 54,2 0,7 0,4 28,6 60,8 0,2 45,2 65,2 38,2 0,8 29,6 10,0 5,2 1,5 3,4 MW : 35,5 45,7 1,1 12,5 11,1 27,3 9,8 22,8 Rhodonia placenta (HFA 58) 0,8 53,5 0,8 0,4 0,3 8,2 0,4 0,4 0,7 22,1 1,1 1,1 1,0 38,5 1,2 0,1 0,4 38,8 0,7 1,4 1,1 58,7 1,3 0,4 1,0 2,2 0,3 0,5 0,3 3,8 0,8 1,1 0,5 1,2 0,8 0,8 1,2 25,0 1,0 1,1 0,8 1,2 0,2 0,7 0,0 0,0 1,4 0,3 MW: 0,7 19,8 0,7 0,8 0,6 22,4 1,0 0,6

[0051] Figure 3 shows the samples in the test vessels immediately before removal from the fungal experiment, with 6 parallel samples each divided between 2 test vessels. In the left-hand image, all samples in the left test vessel are overgrown with Rhodonia placenta, with growth of Tr. virens (HFA 347) visible underneath. In the right-hand test vessel, it is obvious that Tr. virens (HFA 347) has completely overgrown Rhodonia placenta and the wood samples. In the middle, it can be seen in both test vessels that Rhodonia placenta has overgrown the wood samples, but Tr. virens (HFA 347) is clearly spread underneath. In the right-hand image, in the left test vessel, Gloeophyllum trabeum has overgrown 2 samples and the untreated control, and one sample was overgrown by Tr. virens (HFA 347).

[0052] Pretreatment with Tr. harzianum (HFA 335) prevented wood degradation by Rhodonia placenta in all cases. Even 2 minutes of immersion time were sufficient for a protective effect. However, with pretreatment with Tr. virens (HFA 347), this was the case with immersion times of 30 and 240 minutes, but not with 2 and 60 minutes. As can be seen from Table 6, there were sometimes large differences in mass losses among the 6 parallel samples. In the fungal experiment, 3 of the 6 parallel samples were incubated with an untreated control in a test vessel. In the case of pretreatment with Tr. virens (HFA 347) and 2 minutes of immersion time, the results were clearly attributable to the two test vessels: in one, high mass losses were observed in all 3 samples, in the second, none ( Figure 3, left). However, with a 60-minute immersion time, very different mass losses were also achieved, although there was no clear distinction between the test vessels, but rather between the individual samples. Both Trichoderma and the wood-destroying fungus were visible in the test vessels and on the wood ( Figure 3 , center). Which of the fungi gained the upper hand in the battle for the wood was not obvious, but could only be determined based on the mass losses. It can be assumed that the effect of the experimental conditions described in the literature is at play here. This means that even if the experimental conditions are supposedly the same for all samples, small to minimal differences can steer the finely balanced system between the wood-destroying fungus and its antagonists in one direction or the other.

[0053] Gloeophyllum trabeum is evidently more resistant to the Trichoderma strains used than Rhodonia placenta. Only in one case, when the wood samples were pretreated with Tr. harzianum (HFA 335) and immersed for 30 minutes, did none of the six parallel samples exhibit any mass loss. However, after immersion for 60 and 240 minutes, three and two samples, respectively, exhibited significant mass loss. Here, too, the effect of the test conditions described above may have played a role. Although the effectiveness of the antagonists is demonstrable in many samples, in some samples this is clearly insufficient, and the wood-destroying fungus can then assume dominance ( Figure 3 , right). Table 6 also clearly shows that the immersion time has an effect. For example, significantly higher mean mass losses were achieved with 2 minutes of immersion of the samples in liquid culture against Gloeophyllum trabeum than with longer immersion times. Example 4 (Effectiveness in the shift system):

[0054] For the series of tests on the effectiveness of a 3- or 4-layer system, in which the first layer is either a Trichoderma-infested liquid medium, a spore suspension, or an impregnation with an incorporated antagonist, wood samples measuring 110 x 40 x 10 mm were prepared and their end grains sealed. The test logs were pre-cultivated on agar or in liquid media. Tests are conducted both in the field and in the laboratory.

[0055] The two Trichoderma strains tested were Tr. harzianum (HFA 335) and Tr. virens (HFA 347). As previously mentioned, the spore suspension could be incorporated into the impregnation, thus enabling a three-layer structure consisting of impregnation including spore suspension, intermediate coating, and topcoat. The liquid medium was applied in a separate step, followed by the impregnation. The further coating structure was carried out as previously described.

[0056] It was also investigated whether the combined use of the two Trichoderma strains would be effective against both groups of target organisms. For this purpose, the Trichoderma strains were pre-cultivated separately in liquid medium, as described above. The resulting suspensions of the two fungi were then mixed, and sterilized wood samples were immersed in them for 2 and 30 minutes, respectively. At the same time, sterilized wood samples were impregnated with the suspensions of the two fungi using vacuum impregnation. The wood samples were placed in sterile containers, covered with fungal suspension, and then exposed to a negative pressure of 4 kPa for 20 minutes. The wood samples treated with the antagonists in this way were then used, as also described above, in fungal experiments against wood-discoloring and wood-destroying fungi.

[0057] The following variables were examined: (1) Liquid medium in a 4-layer structure: liquid medium; impregnation; intermediate coating; top coating (2) Spore suspension in a 3-layer structure: impregnation with incorporated spore suspension; intermediate coating; top coating (3) An additional series with an artificial injury for the samples in the laboratory against wood-staining fungi

[0058] The standard product with standard structure from Adler Lacke was used as a reference. Example 4a (laboratory tests):

[0059] The samples in the laboratory against wood-destroying fungi are carried out without an intermediate or top coat, since this good physical protection usually prevents the samples from becoming moist in the laboratory test and then it cannot be determined whether the protection is due to the antagonist or the active ingredient or to the moisture protection.

[0060] The results are shown in Table 7 and in Figure 4 shown. Table 7 Average degree of blueing after x minutes of immersion Controls Mixed liquid culture of Liquid culture of Tr. harzianum (HFA 335) and Tr. virens (HFA 347) Tr. harzianum (HFA 335) Tr. virens (HFA 347) 2 minutes 30 minutes 30 minutes 2 minutes 1,0 0,0 2,0 0,0 3,0 0,0 1,0 2,0 1,0 3,0 0,0 1,0 2,0 0,0 3,0 0,0 1,0 2,0 0,0 0,0 1,0 1,0 1,0 0,0 1,0 2,0 1,0 Average: 0.2 Mean: 0.8 Average: 1.8 Average: 0.5 Average: 3.0

[0061] Figure 4 shows the samples after the blue stain test and immersion in a mixed suspension of Tr. harzianum (HFA 335) and Tr. virens (HFA 347). The top panel shows samples after 2 and 30 minutes of immersion in the mixed spore suspension of both Trichoderma strains. The bottom panel shows samples after 2 and 30 minutes of immersion in the suspensions of Tr. harzianum (HFA 335) and Tr. virens (HFA 347). Untreated controls are shown on the right.

[0062] With Tr. harzianum (HFA 335), a significantly lower, yet still noticeable, blueing was observed compared to the untreated controls, which was rated at an average of 1.8. When using Tr. virens (HFA 347), only slight superficial blueing was observed, with an average blueing degree of 0.5. When the two liquid cultures were mixed, average blueing degrees of 0.2 and 0.8, respectively, resulted.

[0063] The use of mixed suspensions of Tr. harzianum (HFA 335) and Tr. virens (HFA 347) did not result in any further reduction in blue staining compared to the suspension of Tr. virens (HFA 347). The achieved mean blue staining levels of 0.2, 0.8, and 0.5, respectively, are attributable to the fundamental variability in biological experiments.

[0064] Table 8 shows mass losses of samples pretreated by immersion in a mixed liquid culture of Tr. harzianum (HFA 335) and Tr. virens (HFA 347) after 12 weeks of fungal testing with Coniophora puteana, Gloeophyllum trabeum and Rhodonia placenta. Table 8: Mass losses 2 minutes dive time 30 minutes diving time C. puteana (HFA 10) G. trabeum (HFA 53) Rh. placenta (HFA 58) C. puteana (HFA 10) G. trabeum (HFA 53) Rh. placenta (HFA 58) 0,92 45,5 0,56 1,38 31,7 0,02 0,44 0,54 1,00 2,07 15,5 1,54 0,00 52,8 1,03 0,49 32,9 1,87 0,52 19,6 1,76 0,60 1,38 0,41 10,4 11,9 1,23 0,00 1,34 0,49 1,05 15,0 0,49 0,00 0,98 1,15 2,2 24,2 1,0 0,8 14,0 0,9 Mean controls: 35,1 58,5 35,6 35,6 55,0 34,8

[0065] As can be seen, pretreatment with the mixed suspension of both fungi prevented wood degradation by Rhodonia placenta after both 2 and 30 minutes of immersion. Very good protection against Coniophora puteana was also achieved; after 30 minutes of immersion, none of the six parallel samples showed any significant mass loss.

[0066] Table 8 also shows that an immersion time of 30 minutes provided slightly better protection than an immersion time of 2 minutes. Again, the parallel samples did not exhibit comparably high mass losses, but with mass losses ranging from 0.98% to 32.9%, the samples exhibited a fairly wide range. This is presumably due to small differences that steer the finely balanced system between the wood-destroying fungus and its antagonists in one direction or the other. Example 4b (field trials):

[0067] The samples for the test series on the effectiveness of a 3- or 4-layer system were also exposed outdoors. In this test setup, the first layer was either a Trichoderma-infested liquid medium or an impregnation with an incorporated antagonist. The samples were exposed outdoors at 45°, oriented southwest, as in Figure 5 can be seen.

[0068] After 4, 8, 12, 16, 20, 26, 37, 41, 45, 48, 51, 53, and 57 weeks of outdoor exposure, the sample surfaces were assessed for blue stain growth. The assessment key defined in EN 16492, Table A.3, which is given in Table 9, was used. Table 9: Rating figure Percentage area of ​​vegetation or blueing 0 No growth on the surface of the sample 1 up to 10% growth on the surface of the sample 2 over 10% up to 30% growth on the surface of the sample 3 over 30% up to 50% growth on the surface of the sample 4 over 50% up to 100% growth on the surface of the sample

[0069] In Figures 6-7 One of the three parallel samples is shown before field exposure (0 weeks) and after 37, 51 and 57 weeks of field exposure. Figure 6 concerns the structure in the 3-layer system and Figure 7The 4-layer system structure. In the figures, DB = topcoat, o WS = without active ingredient, m WS = with active ingredient, oV = without injury, and mV = with injury. From 51 weeks: the top row represents the surface evaluation, the bottom row that of the edges. The mean of the evaluation numbers of the 3 parallel samples is shown below each photo. From week 45 onwards, the evaluation was carried out separately for the sample surface and edges, as from this point onwards it was apparent that some samples were showing signs of greying and blueing, starting at the edges.

[0070] In Figures 8-9 The development of superficial blue staining is shown graphically. Figure 8 shows the development of the surface blueing of the samples when built up in the 3-layer system over time. Figure 9 shows the development of the surface blueing of the samples when built up in the 4-layer system over time.

[0071] After 26 weeks, all sample surfaces treated with Trichoderma in a 3- or 4-layer structure, as well as those of the reference samples, were free of blue stain growth. After 37 weeks, those samples with surface injuries showed slight blue staining starting from the injuries, which expanded slightly by 45 weeks. Only the samples treated with the 3-layer structure, with active ingredients in both the intermediate and top coats, showed no blue staining after 37 weeks; blue staining was first noticeable after 45 weeks. In both the 3- and 4-layer structure and the injured samples, a significant increase in blue staining was observed between weeks 51 and 53. No difference was discernible between the samples treated with Trichoderma harzianum and Trichoderma virens.

[0072] Slight blueing of the reference samples first appeared after 37 weeks on a sample with an artificially damaged surface. After 45 weeks, slight graying was observed at the edges of this sample. In the reference samples without any damage, such slight graying and blueing, starting at the edges, only appeared after 51 weeks.

[0073] The untreated controls showed initial growth of blue stain fungi after just 4 weeks; after 20 weeks, one of the 6 replicate samples was already rated as 2. After 26 weeks, the average rating was 2.2, after 37 weeks it was 3.3, and after 45 weeks, all sample surfaces were rated as 4.

[0074] The overall results of the tests in Example 4 show that Tr. harzianum (HFA 335) was more effective against wood-destroying fungi than Tr. virens (HFA 347). However, Tr. virens (HFA 347) was more effective against wood-discoloring fungi than Tr. harzianum (HFA 335).

Claims

1. A method for producing a wooden component coated on at least one surface, which has biological protection against attack by wood-destroying and / or wood-discoloring fungi, comprising the impregnation of the wooden component by applying an impregnating agent to the surface, and the subsequent application of a further coating agent different from the impregnating agent to the impregnated surface to obtain a covering layer, characterized by thatthe impregnating agent is mixed with a pre-culture of and / or with spores of a fungus that is antagonistic to wood-destroying and / or wood-discoloring microorganisms, or that at least the surface of the wooden component to be coated is immersed in a liquid medium, prior to the application of the impregnating agent, which is mixed with a pre-culture and / or with spores of a fungus that is antagonistic to wood-destroying and / or wood-discoloring microorganisms.

2. Method according to claim 1, characterized in that the coating agent for obtaining the top layer is free from a pre-culture or spores of the fungus and preferably generally free from cells of a fungus.

3. Method according to one of the preceding claims, characterized in that the fungus that acts antagonistically against wood-destroying and / or wood-discoloring microorganisms is a fungus of the genus Trichoderma.

4. Method according to claim 3, characterized in that the fungus is a fungus of the genus Trichoderma with the scientific name Trichoderma harzianum, which was deposited with the DSMZ on 17 April 2024 (depositor's reference number: HFA 335) and received the accession number DSM 34998, a fungus of the genus Trichoderma with the scientific name Trichoderma virens, which was deposited with the DSMZ on 17 April 2024 (depositor's reference number: HFA 347) and received the accession number DSM 35005, or a combination thereof.

5. Method according to one of the preceding claims, characterized in that the immersion time of the wooden component in the liquid medium is between 30 seconds and 5 minutes, preferably between 1 and 3 minutes.

6. Method according to one of the preceding claims, characterized in thatthe impregnating agent mixed with the preculture and / or the spores is produced in a preceding process step by adding a liquid medium mixed with the preculture and / or the spores to an existing impregnating agent.

7. Method according to one of the preceding claims, characterized in that the impregnating agent comprises binders, in particular those from the group of alkyd, polyurethane or acrylic resins.

8. Method according to one of the preceding claims, characterized in that the impregnating agent comprises auxiliaries, in particular wetting and dispersing agents, co-solvents, defoamers, light stabilizers, hydrophobic agents, thickeners or fibers.

9. Method according to one of the preceding claims, characterized in thatthe impregnating agent comprises an in-can preservative, preferably selected from the group 1,2-benzisothiazol-3(2H)-one, 2-methyl-2H-isothiazol-3-one, 2-octyl-2H-isothiazol-3-one, 5-chloro-2-methyl-2H-isothiazol-3-one, bronopol, or sodium pyrithione.

10. Method according to one of the preceding claims, characterized in that the additional coating agent contains one or more pigments or fillers.

11. Method according to one of the preceding claims, characterized in that the process is a preventive process to protect the wooden component from fungal infestation and the wood is free from harmful fungal infestation before the process is applied.

12. A wooden component having a coating on at least one of its surfaces and having biological protection against attack by wood-destroying and / or wood-discoloring fungi, produced by a method according to any one of the preceding claims.

13. Use of a wooden component according to claim 12 as a building material in window, door, facade, balcony and building construction, in particular in outdoor areas.

14. Fungus of the genus Trichoderma with the scientific name Trichoderma harzianum, which was deposited with the DSMZ on 17 April 2024 (depositor's reference: HFA 335) and received the accession number DSM 34998, or spores thereof.

15. Fungus of the genus Trichoderma with the scientific name Trichoderma virens, which was deposited with the DSMZ on 17 April 2024 (depositor's reference: HFA 347) and received the accession number DSM 35005, or spores thereof.