Method for improving corrosion resistance and termite resistance of wood materials

Abstract

The invention relates to a method for treating a wood material for improving the corrosion resistance and termite resistance of the wood material, in which the wood material is treated with a water-based formulation containing a zirconium salt, followed by a drying step at a temperature of 0 DEG C to 100 DEG C. The method can obtain a decay-resistant wood material and has improved termite resistance compared to wood materials that use the same water-based formulation but are dried at higher temperatures.

Description

Technical Field

[0001] The present disclosure generally relates to a method for treating wood materials to improve the decay resistance and termite resistance of the wood materials. The method includes applying an aqueous formulation containing a zirconium salt to the wood materials and then performing a drying step. In addition, the present disclosure also relates to wood materials treated according to this method and products containing such wood materials. Background Art

[0002] With the increasing demand for wood materials (such as for building components and furniture), there is a growing need for wood materials that exhibit resistance to outdoor factors such as decay and insects.

[0003] A common insect that causes severe structural damage to wood materials is termites. Termites are wood-eating insects that feed on cellulose in plants and wood materials. When wood materials are attacked by termites, the structural integrity of the materials is damaged due to the formation of cavities within the materials by the termites. Therefore, it is very important to minimize or completely eliminate termite attack on wood materials if the wood materials need to maintain structural stability over a long period.

[0004] Similarly, decay caused by fungi also leads to the structural degradation of wood materials.

[0005] Conventionally, various biocides and insecticides have been used to protect and preserve wood materials against decay and / or termites. These compounds generally have negative impacts on human health and the environment. Therefore, there is still a need for a solution to improve the decay resistance and / or termite resistance of wood materials without having negative impacts on human health and the environment.

[0006] Zirconium is the 20th most abundant element in the earth's crust and is located in Group IVB of the periodic table. The polymeric substances of zirconium in aqueous solutions can chemically and physically interact with different functional groups of organic polymers. The reactions of aqueous zirconium substances with, for example, carboxyl, hydroxyl, and amine groups are known. The reaction of zirconium with the functional groups of organic polymers can be significantly controlled by changing the temperature, pH, and chelating agents. Based on the dosage, physical parameters, and degree and type of functionality in the organic polymer, zirconium polymeric substances can induce crosslinking bonds, improve the adhesion properties of the treatment and the surface, and increase the resistance to heating, washing, water, and / or solvents.

[0007] Previously, zirconium salts have been proposed as reagents for preventing the microbial degradation of wood products, for example, see WO2021 / 118450. However, this document completely lacks the termite resistance of the resulting wood products.

[0008] Therefore, there is still a need for a method to improve the decay resistance and termite resistance of wood materials without using environmentally harmful or toxic components. Summary of the Invention

[0009] The object of the present disclosure is to provide a method for improving the decay resistance and termite resistance of wood materials by using a water-based preparation containing a zirconium salt.

[0010] Another object of the present disclosure is to provide a method for improving the decay resistance and termite resistance of wood materials by using environmentally friendly components or non-toxic components.

[0011] Another object of the present disclosure is to provide a wood material treated by any method of the present disclosure, wherein the wood material exhibits improved decay resistance and / or termite resistance.

[0012] In a first aspect, the present disclosure relates to a method for treating wood materials to improve the decay resistance and termite resistance of the wood materials, wherein the wood materials are treated with a water-based preparation, and the method comprises the following steps:

[0013] i) providing the wood material;

[0014] ii) providing a water-based preparation containing a zirconium salt;

[0015] iii) coating the wood material with the water-based preparation; and

[0016] iv) drying the wood material having the water-based preparation at a temperature of 0 °C to 100 °C.

[0017] The zirconium salt contained in the water-based preparation is used as a termite repellent and a rot protecting agent.

[0018] "Termite repellent" means that the compound mentioned provides improved termite resistance to the treated wood material. Compared with the untreated wood material, the wood material treated with the water-based preparation of the present disclosure has a reduced attractiveness to termites. The zirconium salt directly contributes to termite repellency and makes the treated wood not attract termites. Termite repellency also means termite resistance.

[0019] Similarly, the zirconium salt directly contributes to the decay resistance of the wood material.

[0020] Through this exemplary method, an environmentally friendly method for improving the decay resistance and termite resistance of wood materials is achieved. Since the zirconium salt is used as a termite repellent and a rot protecting agent, there is no need to use environmentally harmful components or toxic components as biocides and / or insecticides. A common biocide exhibiting toxicity and environmentally harmful characteristics is copper.

[0021] The water-based preparation may further contain additives to improve the operability of the water-based preparation or the impregnation efficiency of the preparation. The additive may be an antifoaming agent.

[0022] It has surprisingly been found that coating a water-based formulation containing a zirconium salt onto a wood material and drying the material at a temperature from 0°C to 100°C will produce a wood material having improved termite repellency and exhibiting rot resistance.

[0023] From an environmental perspective, low-temperature drying is also desirable as it reduces the energy consumption during manufacturing.

[0024] More precisely, it has been found that if a wood material treated with a water-based formulation containing a zirconium salt is dried at a high temperature (i.e., above 100°C), the termite resistance will be weakened compared to using a lower drying temperature (i.e., below 100°C).

[0025] Compared with a wood material treated with the same water-based formulation but dried at a higher temperature, treating a wood material with a water-based formulation containing a zirconium salt in combination with a drying step according to the present disclosure enables the rot-resistant wood material to exhibit improved termite resistance. A higher temperature means a temperature higher than the temperature used in the present disclosure.

[0026] Without being bound by theory, it is believed that the temperature used in the present disclosure avoids the formation of degradation products that may occur in the case of using a higher temperature. These degradation products can attract termites. Accordingly, the method of the present disclosure improves the termite resistance of the treated wood material while providing rot resistance.

[0027] The zirconium salt may be selected from, but not limited to, zirconium acetate, ammonium zirconium carbonate, zirconium bromide, zirconium chloride, zirconium hydroxynitrate, zirconium nitrate, zirconium oxide diperchlorate octahydrate, zirconium oxychloride, zirconium oxynitrate, zirconium sulfate, zirconium sulfate tetrahydrate, zirconyl chloride, zirconium acetate hydroxide, zirconium orthosulfate, and zirconium sulfamate.

[0028] The wood materials used in conjunction with the present disclosure may be selected from: spruce, pine, birch, oak, mahogany, cedar, or composite materials (such as plywood, fiberboard, particle board), or pulp-based materials (such as cardboard, corrugated cardboard, plasterboard, specialty paper, or molded pulp products).

[0029] The drying step iv) of the present disclosure can be carried out using any drying and heating techniques under different atmospheric conditions, such as Westwood process, ThermoWood process, Plato process (Ruyter 1989; Boonstra, Tjeerdsma and Groeneveld 1998), Retification (Vernois 2000), Les Bois process, thermal vacuum process (Vacwood), microwave, IR, pulse, induction, air drying, Kiln drying, etc. In addition, the drying step iv) can also be carried out without any additional drying aids, which means that the treated wood material can be dried at the ambient temperature indoors or outdoors depending on the conditions. Non-limiting examples of the atmospheric conditions that can be used are inert atmospheres, such as nitrogen atmosphere, steam and ambient atmosphere or reduced ambient atmosphere. The drying step can be carried out under different program cycles, heating rates and heating times.

[0030] In an exemplary method, the water-based formulation does not contain any additional biocides, fungicides and / or termite repellents in an amount sufficient to act as a biocide, fungicide and / or termite repellent. In an exemplary method, the water-based formulation does not contain any additional biocides.

[0031] Treating the wood material with the water-based formulation of the present disclosure improves the decay resistance and termite resistance of the wood material without the need for any additional biocides, fungicides and / or termite repellents to be present in the water-based formulation.

[0032] In an exemplary method, coating the water-based formulation on the wood material causes the water-based formulation to impregnate into the structure of the wood material.

[0033] The water-based formulation containing zirconium salt not only impregnates the top surface of the wood material to be treated, but also can penetrate into the structure of the wood material.

[0034] By this exemplary method, the water-based formulation diffuses within the structure of the wood material. Thus, the decay resistance and termite resistance throughout the material, not just the top surface, are improved.

[0035] In an exemplary method, the drying step iv) is carried out at a temperature of 0 °C to 80 °C, preferably 10 °C to 70 °C. In a preferred exemplary method, the drying step iv) is carried out at an ambient temperature of 20 °C to 50 °C.

[0036] It has been found that by treating the wood material with the water-based formulation containing zirconium salt and drying at the temperature of the present disclosure, the decay resistance and termite resistance of the treated wood material are improved. Surprisingly, it has been found that if the temperature used is too high, the termite resistance decreases.

[0037] Accordingly, a wood material having improved rot resistance and termite resistance as compared to untreated wood material is manufactured. Further, the method is environmentally friendly because the energy consumption is reduced as compared to a method using a higher drying temperature.

[0038] In an exemplary method, the zirconium salt constitutes the main source of the termite repellent and / or rot preventive agent in the water-based formulation.

[0039] By this exemplary method, since the risk of zirconium to humans and the environment is low, an environmentally friendly method can be provided.

[0040] The main source of the termite repellent and / or rot preventive agent means that if there are additional compounds in the water-based formulation that can be used as rot preventive agents and / or termite repellents, the content of the zirconium salt is higher than the content of such additional compounds. In one embodiment, if there is another source of termite repellent and / or rot preventive agent, the amount of the zirconium salt is at least 70 wt% or at least 80 wt% higher than the amount of the other compound used as a rot preventive agent and / or termite repellent.

[0041] In an exemplary method, the zirconium salt includes zirconium acetate. In an exemplary method, the zirconium salt is zirconium acetate.

[0042] In an exemplary method, the water-based formulation further contains a surfactant. The surfactant can be ionic or non-ionic. The surfactant can be selected from the class of surfactants defined as non-ionic emulsifiers having a HLB (hydrophilic-lipophilic balance) value of 1 to 41 and having wetting properties on wood.

[0043] In an exemplary method, the water-based formulation contains 70 wt% to 99.99 wt% of water, preferably 80 wt% to 99 wt% of water, preferably 90 wt% to 97 wt% of water. In an exemplary method, the water-based formulation contains 90 wt% to 95 wt% of water.

[0044] By having a large amount of water, the formulation is more environmentally friendly because the use of other solvents (such as organic solvents) is reduced or avoided.

[0045] In an exemplary method, the zirconium salt is provided in an amount sufficient to provide improved rot resistance and termite resistance to the wood material.

[0046] By this exemplary method, the termite resistance of the treated wood material is improved because termites are not attracted to the wood material. Since the risk of zirconium to humans and the environment is low, this exemplary method provides an environmentally friendly method for manufacturing termite-resistant wood.

[0047] In an exemplary method, the water-based formulation comprises from 0.1% to 20% by weight of a zirconium salt, preferably from 1% to 15% by weight, more preferably from 3% to 10% by weight of a zirconium salt. In an exemplary method, the water-based formulation comprises from 5% to 10% by weight of a zirconium salt.

[0048] It has been found that by applying a water-based formulation containing such an amount of zirconium salt to a wood material and drying it at a temperature as disclosed in the present disclosure, both the decay resistance and termite resistance of the wood material are improved.

[0049] In an exemplary method, the water-based formulation contains from 3% to 10% by weight of a zirconium salt and from 90% to 97% by weight of water.

[0050] In an exemplary method, the water-based formulation contains from 3% to 10% by weight of a zirconium salt and from 90% to 97% by weight of water.

[0051] In an exemplary method, the water-based formulation does not contain environmentally harmful components or toxic components.

[0052] Toxic components refer to components that are toxic, especially those that can cause death or severe debilitation. Environmentally harmful components refer to components that pose a threat to the surrounding natural environment or have an adverse impact on people's health.

[0053] Since the water-based formulation of the present disclosure provides a wood material with improved decay resistance and termite resistance without the need for any additional biocides or insecticides, a formulation that does not pose a risk to people in contact with the treated wood material or the usage environment of the wood material can be provided.

[0054] In an exemplary method, the pH value of the water-based formulation is from 2 to 13, preferably from 2 to 9.

[0055] In an exemplary method, the coating step iii) is carried out by vacuum pressure impregnation.

[0056] In an exemplary method, the method further comprises a pretreatment step of drying the wood material to a moisture content of less than 20% before applying the water-based formulation.

[0057] By this exemplary method, more effective impregnation of the water-based formulation is achieved.

[0058] The drying pretreatment step can be carried out using any drying technique, such as microwave, IR, pulsed, induction, air drying, Kiln drying, dehumidification, vacuum drying, solar kiln, water seasoning, boiling or steam drying, chemical or salt drying, electric drying, etc. The method can be carried out in the absence or presence of a vacuum, inert atmosphere, steam or ambient atmosphere.

[0059] In an exemplary method, the treated wood material exhibits a visual sample termite degradation of less than 3, preferably less than 2, when measured according to EN 117 (2012) (the measurement time is adjusted from 8 weeks to 6 weeks).

[0060] En 117 (2012) provides a laboratory method for testing the effectiveness of wood preservatives against termites. It allows the determination of the product concentration that prevents the infestation of impregnated wood by these insects in susceptible species. This laboratory method provides a standard by which the value of the product can be evaluated. EN 117 (2012) has been adjusted to a measurement time of 6 weeks in the present disclosure. Termite infestation of treated and untreated wood materials is carried out, and after the test period, a score of 0 to 5 is given based on their visual appearance after infestation, where 0 = no infestation and 4 = severe infestation.

[0061] In an exemplary method, the method causes the treated wood material to exhibit a durability class of less than 3, preferably less than 2, according to prEn 113-2 (2018).

[0062] prEn 113-2 (2018) provides a method for determining the durability of wood materials against wood-destroying fungi. This method is applicable to all wood species. In addition, this method can be used to test modified wood. Different fungal strains are applied to treated and untreated wood materials, and after the test period, a score of DC1 to DC5 is given based on their durability after treatment, where DC1 = very durable and DC5 = not durable.

[0063] In a second aspect, the present disclosure relates to a wood material treated by the method according to any one of the first aspects.

[0064] As previously mentioned, the wood materials used in conjunction with the present disclosure can be selected from: spruce, pine, birch, oak, mahogany, cedar, or composite materials (such as plywood, fiberboard, particle board), or pulp-based materials (such as cardboard, corrugated cardboard, gypsum board cardboard, specialty paper, or molded pulp products).

[0065] The wood material treated by the method according to any one of the first aspects will exhibit improved rot resistance and / or termite resistance. In addition, since zirconium salts are non-toxic components, the wooden material exhibits improved rot resistance and / or termite resistance without using components that are harmful to the environment or harmful or toxic to the human body.

[0066] In an exemplary wood material, the wood material contains a termite-repellent amount of zirconium salt.

[0067] In a third aspect, the present disclosure relates to a product comprising the wood material according to any one of the second aspect.

[0068] The product can be, but is not limited to, outdoor wood products for patios and gardens, such as deck boards, fences, planters, outdoor furniture, and docks. Detailed Description

[0069] The detailed description with reference to the disclosed embodiments will be regarded as an example of the combination of the above - specific features. It should be understood that other instances can be achieved by combining other and / or fewer / more features than the disclosed embodiments. Thus, the drawings disclose exemplary embodiments, rather than exclusive combinations. It should also be noted in the context that, for simplicity, all the drawings are disclosed in a schematic manner unless otherwise stated.

[0070] As used herein, "wt%" refers to the weight percentage of the ingredient involved in the total weight of the compound or composition.

[0071] Examples

[0072] In the following examples, different water - based formulations and drying temperatures were analyzed. The formulations were coated onto the wood material, followed by a drying step, and the resulting decay resistance and termite resistance were evaluated.

[0073] Example 1: General preparation procedure of the water - based formulation of the present disclosure

[0074] Method 1

[0075] Step a) Mix the zirconium salt formulation and water in any addition order,

[0076] Step b) Add an antifoaming agent, a wetting agent, and other optional components to the resulting mixture in step a), where the resulting mixture in steps a - b is optionally mixed and / or optionally homogenized.

[0077] Method 2

[0078] Step a) Add an antifoaming agent, a wetting agent, and other optional components to water,

[0079] Step b) Add the zirconium salt to the resulting mixture in step a), where the resulting mixture in steps a - b is optionally mixed and / or optionally homogenized.

[0080] Equipment for preparing aqueous formulations is any kind of laboratory or industrial equipment that uses low shear force and / or high shear force to produce the homogeneous compositions of the present disclosure. This can be a magnetic stirrer, an overhead stirrer with a propeller or disperser, etc., a homogenizer with or without high pressure, an in-line or external homogenizer, an extruder, a vibrating device, a mortar and pestle, a blender-type instrument, any kind of mixer (static mixer, micro mixer, vortex mixer, industrial mixer, ribbon blender, V-blender, continuous processor, conical screw blender, helical blender, double conical blender, double planetary mixer, high viscosity mixer, counter-rotating, biaxial and triaxial, vacuum mixer, high shear rotor-stator, dispersive mixer, paddle, jet mixer, mobile mixer, drum mixer, hybrid mixer, planetary mixer, Banbury mixer, etc.), a Friabilator, a grinder, a mill (ground by a bead mill, colloid mill, hammer mill, ball mill, rod mill, autogenous mill, semi-autogenous mill, pebble mill, high pressure grinding roll, pan mill, vertical shaft impact mill, tower mill, etc.), sonication, a rotor-stator mechanical device, any kind of propeller or mixer, a high temperature and / or high pressure asphalt emulsifier or a combination of the above.

[0081] Example 2: Resistance to decay

[0082] The test was carried out according to the test method for wood-destroying basidiomycetes - Part 2 of prEN 113-2 (2018) standard. Four different pine wood treatment methods were evaluated according to Table 1.

[0083] The coated aqueous formulation was prepared according to Method 1. The aqueous formulations for Treatments 1 to 4 contained water and zirconium acetate. As shown in Table 1, Treatments 1 to 3 had different concentrations of zirconium acetate. The treatments used are shown in Table 1. In this example, the reference material used was untreated pine sapwood.

[0084] Table 1

[0085] Processing number Coated aqueous preparation Drying temperature 1 3% zirconium acetate 60℃ 2 5% zirconium acetate 60℃ 3 10% zirconium acetate 60℃ 4 - Up to 185 °C

[0086] For Treatments 1 to 4, impregnation was carried out at room temperature (about 21 °C) under a pressure of 11 bar for 3 hours. The moisture absorption of the aqueous formulation was 730 kg / m 3 to 760 kg / m 3 .

[0087] For a drying temperature of 60 °C, the wood material was dried for about 4 to 6 days. For a drying temperature of 185 °C, the temperature was gradually increased over 4 to 6 days to reach a maximum temperature of 185 °C.

[0088] The test blocks of the wood material analyzed had dimensions of 50 mm x 25 mm x 15 mm. The tests were carried out in accordance with prEN 113-2 (2018); section 7.2.

[0089] First, the test blocks were conditioned at 20 ± 2 °C and 65 ± 5% humidity until a stable weight was reached. Subsequently, the aging test was carried out in accordance with EN84.

[0090] The fungi analyzed were Trametes versicolor, Rhodonia placenta, and Coniophora puteana. For each treatment, the test blocks were incubated with one of the above fungi for 112 days. After 112 days, the median mass loss was measured and the inherent durability or enhanced durability was evaluated in accordance with Appendix F1 of prEN 113-2 (2018). The results are shown in Table 2.

[0091] Table 2

[0092]

[0093] The definition of the durability class scale according to Appendix F1 of prEN 113-2 is shown in Table 3 below:

[0094] Table 3

[0095] Durability class Description Percentage of mass loss DC 1 Very durable ≤5 DC 2 Durable >5 to ≤10 DC 3 Moderately durable >10 to ≤15 DC 4 Slightly durable >15 to ≤30 DC 5 Not durable >30

[0096] As can be seen from Table 2 and Table 3, the treated wood materials exhibited good rot resistance. In addition, higher rot resistance can be achieved by increasing the concentration of zirconium salts in the water-based formulation.

[0097] Example 3: Termite resistance

[0098] In this test, the termite feeding behavior on variants of modified pine wood was tested. In addition, untreated pine sapwood and untreated oak sapwood were also tested as references and virulence controls. The test was carried out in accordance with EN 117 (2012), and the measurement time was adjusted to 6 weeks.

[0099] Seven different treatments of treated and untreated pine wood were evaluated according to Table 4.

[0100] The coated water-based formulation was prepared according to Method 1. The water-based formulations for Treatments 1 to 4 contained water and zirconium acetate. As shown in Table 4, Treatments 1 to 4 had different concentrations of zirconium acetate. The treatments used are shown in Table 4. In this example, the reference material used was untreated pine sapwood.

[0101] Table 4

[0102]

[0103] For Treatments 1 to 4, impregnation was carried out at a pressure of 11 bar for 3 hours at room temperature (about 21 °C). The moisture absorption of the water-based preparation was 730 kg / m 3 to 760 kg / m 3 .

[0104] For a drying temperature of 60 °C, the wood material was dried for about 4 to 6 days. For a drying temperature of 185 °C, the temperature was gradually increased over 4 to 6 days to reach a maximum temperature of 185 °C.

[0105] The test block size of the wood material analyzed was 25 x 15 x 5 mm. Each treatment was repeated 6 times. Glass containers filled with moist vermiculite were used as test containers.

[0106] In each test container, a complete set of test samples treated according to Treatments 1 to 10 as shown in Table 4 was fixed. Due to the small size of the test blocks used, a shortened version of the aging test was carried out according to EN 84, with the duration changed from 14 days to 2 days. Then, the test samples were conditioned at 20 °C and 65% humidity for 3 days.

[0107] After conditioning, 120 worker ants and 10 soldier ants of the termite species Mastotermes darwiniensis were placed in each test container, and the feeding behavior of the termites was studied according to EN 117 (2012) (measurement time adjusted to 6 weeks).

[0108] After one week of termite infestation, Treatments 1 to 3 showed less termite degradation.

[0109] After three weeks of termite infestation, Treatments 1 to 3 were not further infested, and termite feeding concentrated on Treatments 4 to 5 and untreated pine sapwood and oak pine sapwood.

[0110] After six weeks of termite infestation, only Treatments 1 to 3 remained largely intact. Treatments 4 to 5 were severely infested, in most cases more severely than untreated pine sapwood (Treatment 9).

[0111] None of the infested test samples seemed to be highly toxic, as the termite colony survival rate was high (83% to 95%) after six weeks.

[0112] After 6 weeks, a visual assessment of each test sample was carried out according to EN 117 (2012). The results are shown in Table 5. Table 5 represents the average of six repetitions for each treatment.

[0113] Table 5

[0114]

[0115] Visual evaluation according to EN 117 (2012) (measurement time adjusted to 6 weeks) is defined as shown in Table 6 below.

[0116] Table 6

[0117]

[0118] As can be seen from Tables 5 and 6, when comparing Treatment 1 with Treatment 4, it is obvious that increasing the drying temperature to above 100 °C, more precisely 185 °C, will damage the termite resistance of the treated wood material. In addition, by increasing the concentration of zirconium salt in the water-based formulation, the overall termite resistance can be further slightly improved.

[0119] Compared with the untreated samples (Treatments 9 to 10), the test materials of Treatments 1 to 3 all showed better termite resistance.

[0120] Example 4: Drying at room temperature

[0121] Tests were conducted to evaluate the durability of wood materials impregnated with the water-based formulations of the present disclosure and to compare the durability with copper-impregnated wood materials. The tests were carried out in accordance with EN-113-2 (2020) and EN 350 (2016) in combination with a leaching procedure according to EN 84 (2020).

[0122] The coated zirconium-containing water-based formulations were prepared according to Method 1. The water-based formulations of Treatment Nos. 1 to 6 contained water and zirconium acetate. As shown in Table 7, Treatments 1 to 6 had different concentrations of zirconium acetate. The treatments used are shown in Table 7. For this example, the reference material used was copper-impregnated wood treated according to the Nordiska prescribed treatment class NTR AB.

[0123] Table 7

[0124] Processing number Coated aqueous preparation Drying temperature 1 5% zirconium acetate 23℃ 2 6% zirconium acetate 23℃ 3 7% zirconium acetate 23℃ 4 8% zirconium acetate 23℃ 5 9% zirconium acetate 23℃ 6 10% zirconium acetate 23℃ Copper-impregnated wood (NTR / AB) - 23℃

[0125] For each treatment, test blocks of 50 x 20 x 15 mm were used. For Treatments 1 to 6, the number of test blocks for each test product was 100, and for the reference wood, the number of test blocks was 30.

[0126] For Treatments 1 to 6, impregnation was carried out at room temperature (about 21 °C) at a pressure of 11 bar for 2 hours. The moisture absorption of the water-based formulation was about 600 kg / m 3 .

[0127] Then, the impregnated test blocks were dried in a cabinet at 23 °C for 4 days. Thereafter, the samples were placed in a climate chamber (23 °C, 50% RH) for further drying. Subsequently, an aging test was carried out according to EN 84.

[0128] The fungi analyzed were Trametes versicolor and Coniophora puteana. For each treatment, the test blocks were incubated with one of the above fungi for 112 days. After 112 days, the median mass loss according to prEN 113-2 (2020) was determined. The results are shown in Table 8.

[0129] Table 8

[0130]

[0131] As can be seen from Table 8, the method of treating wood materials with the aqueous formulation of the present disclosure and drying at room temperature (23 °C) exhibits good decay resistance. When compared with copper-impregnated wood of NTR / AB grade, the method of the present disclosure produces the same or improved properties. In addition, higher decay resistance can be achieved by increasing the concentration of zirconium salt in the aqueous formulation.

Claims

1. A method for treating wood materials to improve the decay resistance and termite resistance of the wood materials, wherein, Treat the wood material with a water-based preparation, the method comprising the following steps: i) Provide the wood material; ii) Provide a water-based preparation containing a zirconium salt; iii) Coat the wood material with the water-based preparation; iv) Dry the wood material having the water-based preparation at a temperature of 0°C to 100°C; wherein the zirconium salt contained in the water-based preparation serves as a termite repellent and a rot inhibitor.

2. The method according to claim 1, wherein, The water-based preparation does not contain any additional biocides, fungicides, and / or termite repellents in an amount sufficient to act as a biocide, fungicide, and / or termite repellent.

3. The method according to any one of the preceding claims, wherein, The drying step iv) is carried out at a temperature of 0°C to 80°C, preferably 10°C to 70°C.

4. The method according to any one of the preceding claims, wherein, The zirconium salt constitutes the main source of the termite repellent and / or rot inhibitor in the water-based preparation.

5. The method according to any one of the preceding claims, wherein, The zirconium salt contains zirconium acetate.

6. The method according to any one of the preceding claims, wherein, The water-based preparation further contains a surfactant, preferably the surfactant is selected from ionic surfactants or non-ionic surfactants.

7. The method according to any one of the preceding claims, wherein, The water-based preparation contains 70% to 99.99% by weight of water, preferably 80% to 99% by weight of water, preferably 90% to 97% by weight of water.

8. The method according to any one of the preceding claims, wherein, The zirconium salt is provided in an amount sufficient to provide improved rot resistance and termite resistance to the wood material.

9. The method according to any one of the preceding claims, wherein, The water-based preparation contains 0.1% to 20% by weight of the zirconium salt, preferably 1% to 15% by weight, even more preferably 3% to 10% by weight of the zirconium salt.

10. The method according to any one of the preceding claims, wherein, The water-based preparation contains 3% to 10% by weight of the zirconium salt and 90% to 97% by weight of water, even more preferably 5% to 10% by weight of the zirconium salt and 90% to 95% by weight of water.

11. The method according to any one of the preceding claims, wherein, The water-based preparation contains 3% to 10% by weight of the zirconium salt and 90% to 97% by weight of water, even more preferably 5% to 10% by weight of the zirconium salt and 90% to 95% by weight of water.

12. The method according to any one of the preceding claims, wherein, The water-based preparation does not contain components harmful to the environment or toxic components.

13. The method according to any one of the preceding claims, wherein, The pH value of the water-based preparation is 2 to 13, preferably 2 to 9.

14. The method according to any one of the preceding claims, wherein, The coating step iii) is carried out by vacuum pressure impregnation.

15. The method according to any one of the preceding claims, the method further comprising a pretreatment step of drying the wood material to a moisture content of less than 20% before coating the water-based preparation.

16. The method according to any one of the preceding claims, wherein, The method causes the treated wood material to exhibit a visual sample termite degradation of less than 3, preferably less than 2, when measured according to EN 117 (2012) with the measurement time adjusted to 6 weeks.

17. The method according to any one of the preceding claims, wherein, The method causes the treated wood material to exhibit a durability class of less than 3, preferably less than 2, according to prEn 113-2 (2018).

18. A wood material treated by the method according to any one of claims 1 to 17.

19. The wood material according to claim 18, wherein the wood material contains a termite-repellent amount of zirconium salt.

20. A product comprising the wood material according to any one of claims 18 and 19.

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