A wood-bamboo composite mildew-proof agent with thermal base coupling stability and a preparation method and application thereof

Abstract

The application discloses a wood-bamboo composite mildew-proof agent with heat-alkali coupling stability and a preparation method and application thereof. The wood-bamboo composite mildew-proof agent uses organic phosphoric acid antioxidants and polymerization-resistant heat stabilizers in combination to improve the antioxidant performance and heat stability of the wood-bamboo composite mildew-proof agent, and inhibits the degradation of the wood-bamboo composite mildew-proof agent under an alkaline environment and high-temperature treatment, thereby reducing the decrease of the mildew-proof performance of wood-bamboo composite materials added with the wood-bamboo composite mildew-proof agent due to a hot-pressing process.

Description

A heat-alkali coupled stable composite antifungal agent for wood and bamboo, its preparation method and application Technical Field

[0001] This invention relates to the field of bamboo anti-mildew treatment technology, and in particular to a wood-bamboo composite anti-mildew agent with heat-alkali coupling stability, its preparation method and application. Background Technology

[0002] Bamboo is an important renewable non-timber forest resource, characterized by rapid growth, short harvesting cycle, and high mechanical strength, holding significant value in social, economic, ecological, and cultural aspects. In its natural environment, the cell walls of bamboo are similar in composition to those of wood, consisting of cellulose, hemicellulose, and lignin. Compared to wood, bamboo cell cavities are rich in nutrients such as carbohydrates, starch, fats, and proteins, making them more susceptible to fungal infection and damage. Existing research indicates that fungi generally do not damage the cell wall structure or reduce the mechanical strength of bamboo, but they can affect its appearance, color, and natural texture to some extent, reducing the economic value and lifespan of bamboo products. Furthermore, long-term exposure to fungal environments can seriously affect health. The spores produced by most fungi can cause respiratory infections and even allergic reactions. For example, Aspergillus flavus secretes trachotoxin, which has strong carcinogenic and pro-cancer effects; Aspergillus niger can cause lung, skin, and gastrointestinal infections. Using antifungal agents to inhibit mold growth in wood and bamboo is one of the important measures to achieve efficient and sustainable utilization of these resources.

[0003] Although organic antifungal agents for wood and bamboo are commonly used for soaking, brushing, or pressure impregnation, their antifungal effect is often significantly affected during the high-temperature hot-pressing process of engineered wood products or reconstituted bamboo due to high-temperature thermal degradation, oxidative degradation, or accelerated degradation in alkaline environments. For example, the reconstituted bamboo antifungal modifier developed in CN107584622A combines azoles, isothiazolinones, and pyrethroids, providing good antifungal properties, but it undergoes a certain degree of degradation under high-temperature hot pressing. For the engineered wood product sector, CN114946868A provides an organic-inorganic composite antifungal agent composed of isothiazolinone compounds, borax, and nano-titanium dioxide, which has advantages of low toxicity and environmental friendliness, but the inorganic components suffer from insufficient long-term stability.

[0004] However, for both reconstituted bamboo and engineered wood products, existing organic anti-mold agents are not stable enough in high-temperature and alkaline environments, and their anti-mold effect still suffers from bottlenecks such as short duration and weak efficacy, requiring further improvement and optimization. Summary of the Invention

[0005] The technical problem to be solved by the present invention is to overcome the shortcomings of the prior art and provide a wood and bamboo composite antifungal agent with thermal-alkali coupling stability, its preparation method and application, which reduces the oxidative degradation and thermal degradation of organic antifungal agents on wood and bamboo under high temperature and alkaline conditions, and endows bamboo with good antifungal properties.

[0006] To solve the above-mentioned technical problems, the present invention adopts the following technical solution:

[0007] A composite antifungal agent for wood and bamboo with thermal-alkali coupling stability, comprising the following raw material components in parts by weight:

[0008]

[0009] As a further improvement to the above application steps:

[0010] Preferably, it comprises the following raw material components in parts by weight:

[0011]

[0012] Preferably, it comprises the following raw material components in parts by weight:

[0013]

[0014] Preferably, the organophosphate antioxidant includes one or more of tris(2,4-tert-butylphenyl) phosphate, diisodecylphenylphosphonate, triphenyl phosphate, diphenyldecyl phosphate, triphenyl phosphite, phosphite, and hydroxyethylidene diphosphonic acid.

[0015] Preferably, the polymerization-inhibiting heat stabilizer includes one or two of 2,6-di-tert-butyl-4-methylphenol and 2,4,6-trimethylphenol.

[0016] Preferably, the surfactant comprises one or more of the following: polyoxyethylene vegetable oil, polyoxyethylene alkyl aryl ether, polyoxyethylene lauryl ether, polyoxyethylene lanolin ether, polyoxyethylene sorbitan monooleate, and polyoxyethylene monolaurate.

[0017] As a general inventive concept, the present invention also provides a method for preparing the aforementioned heat-alkali coupled stable wood-bamboo composite antifungal agent, comprising the following steps:

[0018] An isothiazolinone organic antifungal agent is dissolved in diethylene glycol and mixed evenly. The mixture is heated and maintained at 40-60℃. An organic phosphoric acid antioxidant, a polymerization-inhibiting heat stabilizer, a surfactant, and water are added and stirred evenly to obtain a wood and bamboo composite antifungal agent with heat-alkali coupling stability.

[0019] As a further improvement to the above technical solution: after adding an organophosphate antioxidant, a polymerization inhibitor heat stabilizer, and a surfactant, stir at a speed of 200-2000 rpm for 5-10 minutes, then add water and stir at a speed of 200-2000 rpm for 10-20 minutes.

[0020] As a general inventive concept, the present invention also provides the application of the aforementioned heat-alkali coupled stable wood-bamboo composite antifungal agent and the heat-alkali coupled stable wood-bamboo composite antifungal agent prepared according to the aforementioned preparation method in the antifungal treatment of bamboo.

[0021] As a further improvement to the above technical solution, the application method includes the following steps:

[0022] S1. The bamboo bundles are impregnated in a heat-alkali coupled stable wood-bamboo composite anti-mildew agent and dried until the moisture content of the bamboo bundles is 8-12%.

[0023] S2. Multiple bamboo bundles are hot-pressed for 6-15 minutes at a pressure of 1-1.5 MPa and a temperature of 120-150℃ to obtain reconstituted bamboo.

[0024] Compared with the prior art, the beneficial effects of the present invention are as follows:

[0025] This invention relates to a heat-alkali coupled stable wood-bamboo composite antifungal agent (heat-alkali coupled stability refers to the good stability of the antifungal agent in the presence of both high temperature and alkaline environment. This environment is generated during the hot pressing of phenolic resin adhesive and lignin adhesive, both of which, especially phenolic resin, are commonly used adhesives in wood-bamboo composites). By combining an organophosphate antioxidant and a polymerization-inhibiting heat stabilizer, the antioxidant enhances the antioxidant's antioxidant properties and thermal stability, inhibiting degradation of the antifungal agent in alkaline environments and under high temperature treatment. This reduces the decrease in the antifungal performance of wood-bamboo composites containing the antifungal agent due to the hot pressing process. Detailed Implementation

[0026] The present invention will be further described in detail below. Unless otherwise specified, the instruments or materials used in the present invention are commercially available.

[0027] Example 1

[0028] This embodiment of a heat-alkali coupled stable wood and bamboo composite antifungal agent comprises the following raw material components by weight: 0.2 parts of isothiazolinone organic antifungal agent (CMIT), 3.8 parts of diethylene glycol, 1.5 parts of organophosphate antioxidant (phosphite), 1.5 parts of polymerization-inhibiting heat stabilizer (2,6-di-tert-butyl-4-methylphenol), 5 parts of surfactant (polyoxyethylene alkyl aryl ether), and 88 parts of water.

[0029] The preparation method of a heat-alkali coupled stable wood-bamboo composite antifungal agent according to this embodiment includes the following steps: 0.5g of 5-chloro-2-methylisothiazolinone (CMIT) is dissolved in 10.0g of diethylene glycol and mixed evenly. 4.0g is taken out, heated and maintained at 40-60℃ (50℃ in this embodiment), and then 1.5g of phosphite, 1.5g of 2,6-di-tert-butyl-4-methylphenol and 5.0g of polyoxyethylene alkyl aryl ether are added. The mixture is stirred at 400rpm for 10min. Then, 88.0g of water is added and stirred at 400rpm for another 20min to obtain a heat-alkali coupled stable wood-bamboo composite antifungal agent.

[0030] This embodiment describes an application method for a heat-alkali coupled stable wood-bamboo composite antifungal agent, comprising the following steps:

[0031] Bamboo bundles with a thickness of 2 mm and a moisture content of 10% were impregnated in the heat-alkali coupled stable wood-bamboo composite antifungal agent of this embodiment. The impregnation pressure was 0.5-0.8 MPa (0.5 MPa in this embodiment) and the impregnation time was 2-10 min (5 min in this embodiment). After impregnation, the bundles were removed and dried at a temperature of 60-80℃ (60℃ in this embodiment) for 24-48 h (36 h in this embodiment) until the moisture content of the bamboo bundles dropped to 8-12% (10% in this embodiment). Phenolic resin was used as an adhesive, and the bamboo bundles were hot-pressed into reconstituted bamboo under the conditions of a hot-pressing pressure of 1.2 MPa, a hot-pressing temperature of 140℃, and a hot-pressing time of 6 min.

[0032] Example 2

[0033] This embodiment of a heat-alkali coupled stable wood and bamboo composite antifungal agent comprises the following raw material components by weight: 0.2 parts of isothiazolinone organic antifungal agent (DCOIT), 3.8 parts of diethylene glycol, 2.5 parts of organophosphate antioxidant (diisodecylphenylphosphonate), 2.5 parts of polymerization-inhibiting heat stabilizer (2,6-di-tert-butyl-4-methylphenol), 7 parts of surfactant (polyoxyethylene alkyl aryl ether), and 84 parts of water.

[0034] This embodiment describes a method for preparing a thermo-alkali coupled stable wood-bamboo composite antifungal agent, comprising the following steps: 0.5g of 4,5-dichloro-N-octyl-4-isothiazolin-3-one (DCOIT) dissolved in 10.0g of diethylene glycol is mixed evenly, 4.0g is taken out, heated and maintained at 40-60℃ (50℃ in this embodiment), then 2.5g of diisodecylphenylphosphonate, 2.5g of 2,6-di-tert-butyl-4-methylphenol and 7.0g of polyoxyethylene alkyl aryl ether are added, and the mixture is stirred at 400rpm for 10min. Subsequently, 84.0g of water is added, and the mixture is stirred again at 400rpm for 20min to obtain a thermo-alkali coupled stable wood-bamboo composite antifungal agent.

[0035] This embodiment describes an application method for a heat-alkali coupled stable wood-bamboo composite antifungal agent, and its application steps are the same as those in Embodiment 1.

[0036] Example 3

[0037] This embodiment of a heat-alkali coupled stable wood and bamboo composite antifungal agent comprises the following raw material components by weight: 0.1 parts isothiazolinone organic antifungal agent (OIT), 1.9 parts diethylene glycol, 2.5 parts organophosphate antioxidant (hydroxyethylidene diphosphonic acid), 4 parts polymerization-inhibiting heat stabilizer (2,4,6-trimethylphenol), 5 parts surfactant (polyoxyethylene sorbitan monooleate), and 86.5 parts water.

[0038] The preparation method of a heat-alkali coupled stable wood-bamboo composite antifungal agent according to this embodiment includes the following steps: 0.5g of 2-octyl-4-isothiazolin-3-one (OIT) is dissolved in 10.0g of diethylene glycol and mixed evenly. 2.0g is taken out, heated and maintained at 40-60℃ (50℃ in this embodiment), and then 2.5g of hydroxyethylidene diphosphonic acid, 4.0g of 2,4,6-trimethylphenol and 5.0g of polyoxyethylene sorbitan monooleate are added. The mixture is stirred at 1000rpm for 6min. Then, 86.5g of water is added and stirred at 400rpm for another 20min to obtain a heat-alkali coupled stable wood-bamboo composite antifungal agent.

[0039] This embodiment describes an application method for a heat-alkali coupled stable wood-bamboo composite antifungal agent, and its application steps are the same as those in Embodiment 1.

[0040] Example 4

[0041] This embodiment of a heat-alkali coupled stable wood and bamboo composite antifungal agent comprises the following raw material components by weight: 0.1 parts of isothiazolinone organic antifungal agent (CMIT), 1.9 parts of diethylene glycol, 2.5 parts of organophosphate antioxidant (hydroxyethylidene diphosphonic acid), 4 parts of polymerization-inhibiting heat stabilizer (2,6-di-tert-butyl-4-methylphenol), 5 parts of surfactant (polyoxyethylene monolaurate), and 86.5 parts of water.

[0042] The preparation method of a heat-alkali coupled stable wood-bamboo composite antifungal agent according to this embodiment includes the following steps: 0.5g of 5-chloro-2-methylisothiazolinone (CMIT) is dissolved in 10.0g of diethylene glycol and mixed evenly. 2.0g is taken out, heated and maintained at 40-60℃ (50℃ in this embodiment), and then 2.5g of hydroxyethylidene diphosphonic acid, 4.0g of 2,6-di-tert-butyl-4-methylphenol and 5.0g of polyoxyethylene monolaurate are added. The mixture is stirred at 1500rpm for 5min. Then, 86.5g of water is added and stirred at 400rpm for another 20min to obtain a heat-alkali coupled stable wood-bamboo composite antifungal agent.

[0043] This embodiment describes an application method for a heat-alkali coupled stable wood-bamboo composite antifungal agent, and its application steps are the same as those in Embodiment 1.

[0044] Comparative Example 1

[0045] This comparative example is a wood and bamboo composite antifungal agent that lacks a polymerization inhibitor and an organophosphate antioxidant. It includes the following raw material components by weight: 0.1 parts isothiazolinone organic antifungal agent (OIT), 1.9 parts diethylene glycol, 0 parts organophosphate antioxidant, 0 parts polymerization inhibitor, 5 parts surfactant (polyoxyethylene alkyl aryl ether), and 93 parts water.

[0046] The preparation method of the wood-bamboo composite antifungal agent of this comparative example includes the following steps: 0.5g of 2-octyl-4-isothiazolin-3-one (OIT) is dissolved in 10.0g of diethylene glycol and mixed evenly. 2.0g is taken out, heated and maintained at 40-60℃ (50℃ in this comparative example), and then 5.0g of polyoxyethylene dehydrated sorbitan monooleate and 93.0g of water are added. The mixture is stirred at 400rpm for 20min to obtain the wood-bamboo composite antifungal agent.

[0047] The application method of the wood-bamboo composite anti-mildew agent in this comparative example is the same as that in Example 1.

[0048] Comparative Example 2

[0049] This comparative example of a wood and bamboo composite antifungal agent lacks a polymerization-inhibiting heat stabilizer and includes the following raw material components by weight: 0.2 parts of isothiazolinone organic antifungal agent (CMIT), 3.8 parts of diethylene glycol, 1.5 parts of organophosphate antioxidant (phosphite), 0 parts of polymerization-inhibiting heat stabilizer, 5 parts of surfactant (polyoxyethylene alkyl aryl ether), and 89.5 parts of water.

[0050] The preparation method of the wood-bamboo composite antifungal agent of this comparative example includes the following steps: dissolving 0.5g of 5-chloro-2-methylisothiazolinone (CMIT) in 10.0g of diethylene glycol, mixing evenly, taking out 4.0g, heating and maintaining at 40-60℃ (50℃ in this comparative example), then adding 1.5g of phosphite and 5.0g of polyoxyethylene alkyl aryl ether, and stirring at 400rpm for 10min, then adding 89.5g of water, and stirring again at 400rpm for 20min to obtain the wood-bamboo composite antifungal agent.

[0051] The application method of the wood-bamboo composite anti-mildew agent in this comparative example is the same as that in Example 1.

[0052] Comparative Example 3

[0053] This comparative example of a wood and bamboo composite antifungal agent lacks an organophosphate antioxidant and includes the following raw material components by weight: 0.2 parts of isothiazolinone organic antifungal agent (CMIT), 3.8 parts of diethylene glycol, 0 parts of organophosphate antioxidant, 1.5 parts of polymerization-inhibiting heat stabilizer (2,6-di-tert-butyl-4-methylphenol), 5 parts of surfactant (polyoxyethylene alkyl aryl ether), and 89.5 parts of water.

[0054] The preparation method of the wood-bamboo composite antifungal agent of this comparative example includes the following steps: dissolving 0.5g of 5-chloro-2-methylisothiazolinone (CMIT) in 10.0g of diethylene glycol, mixing evenly, taking out 4.0g, heating and maintaining at 40-60℃ (50℃ in this comparative example), then adding 1.5g of 2,6-di-tert-butyl-4-methylphenol and 5.0g of polyoxyethylene alkyl aryl ether, and stirring for 10min at 400rpm, followed by adding 89.5g of water to obtain a high-temperature resistant wood-bamboo composite antifungal agent.

[0055] The application method of the wood-bamboo composite anti-mildew agent in this comparative example is the same as that in Example 1.

[0056] Comparative Example 4

[0057] This comparative example describes a composite antifungal agent for wood and bamboo, which uses resveratrol instead of organophosphate antioxidants. It comprises the following raw material components by weight: 0.1 parts isothiazolinone organic antifungal agent (OIT), 1.9 parts diethylene glycol, 2.5 parts resveratrol, 4 parts polymerization-inhibiting heat stabilizer (2,4,6-trimethylphenol), 5 parts surfactant (polyoxyethylene monolaurate), and 86.5 parts water.

[0058] The preparation method of the wood-bamboo composite antifungal agent of this comparative example includes the following steps: 0.5g of 2-octyl-4-isothiazolin-3-one (OIT) is dissolved in 10.0g of diethylene glycol and mixed evenly. 2.0g is taken out, heated and maintained at 40-60℃ (50℃ in this comparative example). Then, 2.5g of resveratrol, 4.0g of 2,4,6-trimethylphenol and 5.0g of polyoxyethylene sorbitan monooleate are added to it, and the mixture is stirred at 1000rpm for 6min. Then, 86.5g of water is added to it, and the mixture is stirred at 400rpm for another 20min to obtain the wood-bamboo composite antifungal agent.

[0059] The application method of the wood-bamboo composite anti-mildew agent in this comparative example is the same as that in Example 1.

[0060] Comparative Example 5

[0061] This comparative example describes a wood and bamboo composite antifungal agent that uses dibutyltin maleate instead of a polymerization-inhibiting heat stabilizer. It comprises the following raw material components by weight: 0.1 parts isothiazolinone organic antifungal agent (OIT), 1.9 parts diethylene glycol, 2.5 parts organophosphonic acid antioxidant (hydroxyethylidene diphosphonic acid), 4 parts polymerization-inhibiting heat stabilizer (dibutyltin maleate), 5 parts surfactant (polyoxyethylene monolaurate), and 86.5 parts water.

[0062] The preparation method of the wood-bamboo composite antifungal agent of this comparative example includes the following steps: 0.5g of 2-octyl-4-isothiazolin-3-one (OIT) is dissolved in 10.0g of diethylene glycol and mixed evenly. 2.0g is taken out, heated and maintained at 40-60℃ (50℃ in this comparative example), and then 2.5g of hydroxyethylidene diphosphonic acid, 4.0g of dibutyltin maleate and 5.0g of polyoxyethylene monolaurate are added. The mixture is stirred at 1000rpm for 6min. Then 86.5g of water is added and stirred at 400rpm for another 20min to obtain the wood-bamboo composite antifungal agent.

[0063] The application method of the wood-bamboo composite anti-mildew agent in this comparative example is the same as that in Example 1.

[0064] Comparative Example 6

[0065] This comparative example of a wood and bamboo composite antifungal agent uses a relatively large amount of organophosphate antioxidants, including the following raw material components by weight: 0.2 parts of isothiazolinone organic antifungal agent (DCOIT), 3.8 parts of diethylene glycol, 10 parts of organophosphate antioxidant (diisodecylphenylphosphonate), 2.5 parts of polymerization-inhibiting heat stabilizer (2,6-di-tert-butyl-4-methylphenol), 7 parts of surfactant (polyoxyethylene alkyl aryl ether), and 76.5 parts of water.

[0066] The preparation method of the wood-bamboo composite antifungal agent of this comparative example includes the following steps: 0.5g of 4,5-dichloro-N-octyl-4-isothiazolin-3-one (DCOIT) and 10.0g of diethylene glycol are dissolved and mixed evenly. 4.0g is taken out, heated and maintained at 40-60℃ (50℃ in this comparative example), and then 10.0g of diisodecylphenylphosphonate, 2.5g of 2,6-di-tert-butyl-4-methylphenol and 7.0g of polyoxyethylene alkyl aryl ether are added. The mixture is stirred at 400rpm for 10min. Then 76.5g of water is added and stirred at 400rpm for another 20min to obtain the wood-bamboo composite antifungal agent.

[0067] The application method of the wood-bamboo composite anti-mildew agent in this comparative example is the same as that in Example 1.

[0068] Comparative Example 7

[0069] This comparative example of a wood and bamboo composite antifungal agent uses a relatively large amount of polymerization-inhibiting heat stabilizer, including the following raw material components by weight: 0.2 parts of isothiazolinone organic antifungal agent (DCOIT), 3.8 parts of diethylene glycol, 2.5 parts of organophosphate antioxidant (diisodecylphenylphosphonate), 10 parts of polymerization-inhibiting heat stabilizer (2,6-di-tert-butyl-4-methylphenol), 7 parts of surfactant (polyoxyethylene alkyl aryl ether), and 76.5 parts of water.

[0070] The preparation method of the wood-bamboo composite antifungal agent of this comparative example includes the following steps: 0.5g of 4,5-dichloro-N-octyl-4-isothiazolin-3-one (DCOIT) and 10.0g of diethylene glycol are dissolved and mixed evenly. 4.0g is taken out, heated and maintained at 40-60℃ (50℃ in this comparative example). Then, 2.5g of diisodecylphenylphosphonate, 10.0g of 2,6-di-tert-butyl-4-methylphenol and 7.0g of polyoxyethylene alkyl aryl ether are added, and the mixture is stirred at 400rpm for 10min. Then, 76.5g of water is added, and the mixture is stirred at 400rpm for another 20min to obtain the wood-bamboo composite antifungal agent.

[0071] The application method of the wood-bamboo composite anti-mildew agent in this comparative example is the same as that in Example 1.

[0072] Comparative Example 8

[0073] This comparative example describes a composite antifungal agent for wood and bamboo, using sodium fatty alcohol polyoxyethylene ether sulfate as the surfactant. It comprises the following raw material components by weight: 0.2 parts isothiazolinone organic antifungal agent (DCOIT), 3.8 parts diethylene glycol, 2.5 parts organophosphate antioxidant (diisodecylphenylphosphonate), 4 parts polymerization-inhibiting heat stabilizer (2,6-di-tert-butyl-4-methylphenol), 7 parts surfactant (sodium fatty alcohol polyoxyethylene ether sulfate), and 82.5 parts water.

[0074] The preparation method of the wood-bamboo composite antifungal agent of this comparative example includes the following steps: 0.5g of 4,5-dichloro-N-octyl-4-isothiazolin-3-one (DCOIT) and 10.0g of diethylene glycol are dissolved and mixed evenly. 4.0g is taken out, heated and maintained at 40-60℃ (50℃ in this comparative example). Then, 2.5g of diisodecylphenylphosphonate, 4.0g of 2,6-di-tert-butyl-4-methylphenol and 7.0g of sodium fatty alcohol polyoxyethylene ether sulfate are added, and stirred at 400rpm for 10min. Then, 82.5g of water is added, and stirred at 400rpm for another 20min to obtain the wood-bamboo composite antifungal agent.

[0075] The application method of the wood-bamboo composite anti-mildew agent in this comparative example is the same as that in Example 1.

[0076] The basic performance parameters of the wood-bamboo composite antifungal agent were tested, focusing on five aspects: appearance, average particle size, centrifugal stability, and storage stability. The average particle size was measured using a Delsa Nano C-type laser particle size analyzer. Centrifugal stability was measured by taking 10.0 g of each of the wood-bamboo composite antifungal agents from Examples 1-4 (heat-alkali coupling stable) and Comparative Examples 1-8, and centrifuging them at 3000 r / min for 30 min. The stability of the wood-bamboo composite antifungal agents was then observed. The results are shown in Table 1.

[0077] Table 1. Basic parameters and performance of the wood-bamboo composite antifungal agents in each embodiment and comparative example.

[0078]

[0079] The results showed that the particle size of all examples and comparative examples was between 28 nm and 80 nm, and the centrifugal stability and storage stability remained good.

[0080] Stability testing of the wood-bamboo composite antifungal agent: 10.0g each of the wood-bamboo composite antifungal agents from Examples 1-4 and Comparative Examples 1-8 were mixed with phenolic resin adhesive at a ratio of 30:70, placed in a petri dish, and heat-treated at 180℃ for 20min. Subsequently, methanol was used to dissolve the active ingredients in the heat-alkali coupled stable composite antifungal agent. HPLC was used to test the content of active ingredients in the composite bamboo antifungal agent before and after heat treatment, and the thermal degradation rate of the active ingredients was calculated. The results are shown in Table 2.

[0081] Table 2. Thermal degradation rate of the effective components of the wood-bamboo composite antifungal agent in each embodiment and comparative example after heat treatment combined with alkali treatment.

[0082]

[0083] The results showed that in Comparative Example 1, which did not contain an organophosphate antioxidant or a polymerization inhibitor heat stabilizer, the active ingredient was significantly degraded. Similarly, in Comparative Example 3 and Comparative Example 2, which did not contain an organophosphate antioxidant or a polymerization inhibitor heat stabilizer, the active ingredient was also significantly pyrolyzed. This demonstrates that a single organophosphate antioxidant or polymerization inhibitor heat stabilizer cannot prevent the degradation of the active ingredient in the antifungal agent. However, Examples 1-4 reduced the degradation rate of the active ingredient caused by combined heat and alkali treatment at 180°C to below 9%, confirming that the combined use of organophosphate antioxidants and polymerization inhibitor heat stabilizers can effectively improve the stability of the antifungal agent. In Comparative Example 4, where resveratrol was used instead of an organophosphate antioxidant, and in Comparative Example 5, where dibutyltin maleate was used instead of a polymerization inhibitor heat stabilizer, the active ingredient was also significantly degraded. This indicates that the superiority of the organophosphate antioxidants and polymerization inhibitor heat stabilizers in improving the stability of the antifungal agent is not achieved by any type of antioxidant or stabilizer. Comparative Example 6, which uses a larger amount of organophosphate antioxidants, and Comparative Example 7, which uses a larger amount of polymerization inhibitor heat stabilizer, demonstrate that the amount of organophosphate antioxidants and polymerization inhibitor heat stabilizers used in this invention is closely related to the ability to improve the stability of the antifungal agent. Not any ratio of organophosphate antioxidants and polymerization inhibitor heat stabilizers can achieve the technical effects achievable by this invention. Comparative Example 8 demonstrates that the type of surfactant in this invention has a synergistic effect with the organophosphate antioxidants and polymerization inhibitor heat stabilizers.

[0084] The anti-mold performance of reconstituted bamboo treated with a wood-bamboo composite anti-mold agent was tested. The anti-mold properties of the reconstituted bamboo from each example and comparative example were tested according to standard GB / T 18261-2013 "Test Method for the Anti-mold Efficacy of Anti-mold Agents against Wood Molds and Discoloration Fungi". An infection value of 0 indicates no mycelia or mold spots on the specimen surface; an infection value of 1 indicates an infected area of ​​<1 / 4; an infection value of 2 indicates an infected area of ​​1 / 4 to 1 / 2; an infection value of 3 indicates an infected area of ​​1 / 2 to 3 / 4; and an infection value of 4 indicates an infected area of ​​>3 / 4. The results are shown in Table 3.

[0085] Table 3 Infection values ​​of reconstituted bamboo treated with wood-bamboo composite antifungal agent

[0086]

[0087] The results showed that the reconstituted bamboo bundles treated with Comparative Example 1, which were not treated with a combination of organophosphate antioxidants and polymerization inhibitors, and then hot-pressed, exhibited an infection value of 4 after one month of mold attack, regardless of whether it was Aspergillus niger or Trichoderma viride. This indicates that under the combined action of heat and alkali, the effective components in the antifungal agent had degraded and could no longer provide antifungal properties for the reconstituted bamboo. The antifungal properties of Comparative Examples 2 and 3 were also poor, demonstrating that the use of organophosphate antioxidants or polymerization inhibitors alone cannot effectively improve the antifungal performance of the composite antifungal agent for reconstituted bamboo. Meanwhile, the antifungal properties of Comparative Examples 4-8 were also poor. The types of organophosphate antioxidants, the dosage of organophosphate antioxidants and polymerization inhibitors, and the types of surfactants in this invention have a synergistic effect. Examples 1-4, which used a combination of organophosphate antioxidants and polymerization inhibitors, all imparted good antifungal properties to the reconstituted bamboo.

[0088] While the present invention has been disclosed above with reference to preferred embodiments, it is not intended to limit the invention. Any person skilled in the art can make many possible variations and modifications to the technical solutions of the present invention, or modify them into equivalent embodiments, without departing from the scope of the present invention. Therefore, any simple modifications, equivalent changes, and modifications made to the above embodiments based on the technical essence of the present invention, without departing from the scope of the present invention, should fall within the protection scope of the present invention.

Claims

1. A composite antifungal agent for wood and bamboo with thermal-alkali coupling stability, characterized in that: The product comprises the following raw material components by weight: 0.1-2 parts of isothiazolinone organic antifungal agent, 1-10 parts of diethylene glycol, 0.1-5 parts of organophosphate antioxidant, 0.1-5 parts of polymerization inhibitor heat stabilizer, 2-20 parts of surfactant, and 60-95 parts of water; wherein the polymerization inhibitor heat stabilizer includes one or two of 2,6-di-tert-butyl-4-methylphenol and 2,4,6-trimethylphenol; and the surfactant includes one or more of polyoxyethylene vegetable oil, polyoxyethylene alkyl aryl ether, polyoxyethylene lauryl ether, polyoxyethylene lanolin alcohol ether, polyoxyethylene sorbitan monooleate, and polyoxyethylene monolaurate.

2. The wood-bamboo composite antifungal agent with heat-alkali coupling stability according to claim 1, characterized in that: It includes the following raw material components by weight: 0.1-1.4 parts of isothiazolinone organic mildew inhibitor, 1.4-5 parts of diethylene glycol, 1.2-3.8 parts of organophosphate antioxidant, 1.4-5 parts of polymerization inhibitor heat stabilizer, 4-16 parts of surfactant, and 70-95 parts of water.

3. The wood-bamboo composite antifungal agent with heat-alkali coupling stability according to claim 2, characterized in that: It includes the following raw material components by weight: 0.1-1.2 parts of isothiazolinone organic mildew inhibitor, 1.5-5 parts of diethylene glycol, 1.5-3 parts of organophosphate antioxidant, 1.5-5 parts of polymerization inhibitor heat stabilizer, 5-8 parts of surfactant, and 70-90 parts of water.

4. The wood-bamboo composite antifungal agent with heat-alkali coupling stability according to any one of claims 1 to 3, characterized in that: The organophosphate antioxidants include one or more of tris(2,4-tert-butylphenyl) phosphate, diisodecylphenylphosphonate, triphenyl phosphate, diphenyldecyl phosphate, triphenyl phosphite, phosphite, and hydroxyethylidene diphosphonic acid.

5. A method for preparing a wood-bamboo composite antifungal agent with thermal-alkali coupling stability according to any one of claims 1 to 4, characterized in that: Includes the following steps: An isothiazolinone organic antifungal agent is dissolved in diethylene glycol and mixed evenly. The mixture is heated and maintained at 40-60℃. An organic phosphoric acid antioxidant, a polymerization-inhibiting heat stabilizer, a surfactant, and water are added and stirred evenly to obtain a wood and bamboo composite antifungal agent with heat-alkali coupling stability.

6. The preparation method of the wood-bamboo composite antifungal agent with heat-alkali coupling stability according to claim 5, characterized in that: After adding organophosphate antioxidants, polymerization inhibitors, and surfactants, stir at 200-2000 rpm for 5-10 minutes. Then add water and stir at 200-2000 rpm for 10-20 minutes.

7. The application of a heat-alkali coupled stable wood-bamboo composite antifungal agent according to any one of claims 1 to 4 and a heat-alkali coupled stable wood-bamboo composite antifungal agent prepared according to the preparation method according to claim 5 or 6 in the antifungal treatment of bamboo.

8. The application according to claim 7, characterized in that: Includes the following steps: S1. The bamboo bundles are impregnated in a heat-alkali coupled stable wood-bamboo composite anti-mildew agent and dried until the moisture content of the bamboo bundles is 8-12%; S2. Multiple bamboo bundles are assembled and hot-pressed for 6-15 minutes under a hot-pressing pressure of 1-1.5MPa and a temperature of 120-150℃ to obtain reconstituted bamboo.

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