Termite-repellent gypsum board with integrated termiticidal mixture and method of production

Abstract

The present invention relates to a termite-repellent gypsum board comprising a gypsum core, a paper or glass fiber facing, and a termiticidal mixture integrated within the gypsum core. The termiticidal mixture includes a termiticidal agent, such as bifenthrin, and a foaming agent in a ratio ranging from 1:1 to 1:5. This mixture imparts effective anti-termite properties to the board. The board is designed to provide long-lasting protection against termite infestations while maintaining the mechanical strength of the gypsum board, including improved core hardness and nail pull resistance. The invention also includes a method for producing the termite-repellent gypsum board, wherein the termiticidal mixture is incorporated into a gypsum slurry, which is then formed into the board and dried at temperatures between 70°C and 200°C. The method optimizes the physical properties of the board, such as pore size and strength, to enhance both termite resistance and structural integrity.

Description

[0001] TERMITE-REPELLENT GYPSUM BOARD WITH INTEGRATED TERMITICIDAL MIXTURE AND METHOD OF PRODUCTION FIELD OF THE INVENTION

[0002] The present invention relates to the field of construction materials, specifically to anti-termite gypsum boards. More particularly, it pertains to the development of gypsum boards that are resistant to termite damage, incorporating a termiticidal mixture that includes a termiticidal agent, and a foaming agent, integrated within the gypsum core and a method thereof.

[0003] BACKGROUND OF THE INVENTION

[0004] Gypsum boards, also referred to as drywall or plasterboard, are widely utilized in the construction industry for walls, ceilings, and partitions due to their ease of installation, costeffectiveness, and fire-resistant properties. However, despite these advantages, gypsum boards are highly susceptible to damage caused by termites, particularly subterranean species. Termites, known for their ability to consume cellulose, are a significant threat to gypsum boards because of the presence of cellulose in the paper facings and starch in the gypsum core. The combination of these organic materials makes the gypsum board vulnerable to termite infestations, leading to structural damage, deterioration, and potential failure of the board over time.

[0005] Subterranean termites, which typically live in the soil, can infiltrate building structures and feed on the cellulose in the paper backing of gypsum boards. As the infestation progresses, termites hollow out sections of the board, compromising its strength and stability. While termites primarily feed on the cellulose in the paper facings, the gypsum core, which also contains organic components like starch, can also be susceptible to their attacks, albeit to a lesser extent.

[0006] To address this issue, recent advancements have focused on incorporating termiticides into the gypsum board matrix to enhance its resistance to termite damage. One such method, disclosed in US10,968,624, involves infusing the gypsum board with a termiticide, such as Clothianidin, to protect the gypsum core. This approach has shown promise in safeguarding the core from termite damage. However, due to its poor water solubility, Clothianidin does not migrate effectively to the paper facings of the gypsum board. As a result, it is typically added to the gypsum slurry only on the top and bottom sides of the board, limiting the distribution of the termiticide.The absence of a comprehensive termite-resistant solution that addresses both the gypsum core and the paper facings of gypsum boards presents a notable challenge in construction. Without protection for the facings, termites can still infiltrate the gypsum board, leading to ongoing damage. This limitation calls for the development of a more robust termite-resistant gypsum board that offers protection against infestations in both the core and the paper facings, ensuring long-lasting durability and structural integrity.

[0007] Moreover, the increasing demand for termite-resistant materials in regions prone to termite infestations underscores the need for a comprehensive solution. These materials should not only provide effective protection against termites but also maintain the structural integrity and sustainability of the board. The growing concern over termite damage, coupled with the need for more durable, cost-efficient, and environmentally friendly construction materials, has increased the need for innovation in the field of termite-resistant gypsum boards. Thus, there is a clear need for an anti-termite gypsum board that offers comprehensive protection from both the core and the paper facings, ensuring long-term resistance to termite damage.

[0008] Therefore, the present invention addresses these challenges by introducing an anti-termite gypsum board that incorporates a termiticidal mixture, including a termiticidal agent and a foaming agent, both integrated into the gypsum core. This ensures comprehensive protection against termites, enhancing the longevity of the gypsum boards and reducing the need for costly repairs and replacements. Moreover, the invention utilizes a highly effective and thermally stable termiticide, which offers advantages over other agents by maintaining its effectiveness during the manufacturing process, where high temperatures are typically involved.

[0009] OBJECT OF THE INVENTION

[0010] The primary object of the present invention is to provide an improved anti -termite gypsum board that offers enhanced protection against termite damage, addressing the vulnerabilities of both the gypsum core and the paper facings.

[0011] Another object of the invention is to incorporate a termiticidal mixture, which includes a termiticidal agent and a foaming agent, into the gypsum core, ensuring comprehensive termite resistance throughout the entire board structure, including the paper facings, which are typically prone to termite attack.A further object of the invention is to provide a method for manufacturing anti -termite gypsum boards, wherein the termiticidal agent is evenly distributed throughout the gypsum core and paper facings, ensuring consistent and long-lasting protection from termites.

[0012] A further object of the invention is to provide a termiticidal mixture that maintains its thermal stability during the gypsum board manufacturing process, which involves high temperature drying, thus ensuring the continued efficacy of the termiticide.

[0013] Another object of the invention is to optimize the process parameters during the manufacturing of gypsum boards to maintain uniform pore sizes, minimize structural defects, and improve the mechanical strength of the resulting anti-termite gypsum boards.

[0014] An additional object of the invention is to provide a cost-effective solution for termiteresistant gypsum boards, reducing the need for frequent repairs, replacements, or additional termite treatments, offering long-term cost savings for consumers, and contributing to sustainable construction practices.

[0015] Finally, the invention aims to meet the growing demand for construction materials that provide effective protection against termite infestations, thereby enhancing the durability, lifespan, and performance of gypsum boards in termite-prone areas.

[0016] SUMMARY OF THE INVENTION

[0017] . According to a primary aspect of the invention, there is provided a termite-repellent gypsum board designed to offer enhanced protection against termite infestation while maintaining the physical integrity of the board. The gypsum board comprises a gypsum core, a paper or a glass fibre facing, and a termiticidal mixture integrated within the gypsum core. This termiticidal mixture contains a termiticidal agent and a foaming agent in a ratio ranging from 1:1 to 1:5, which imparts effective anti-termite properties. The termiticidal agent includes, but is not limited to, bifenthrin, and may be in various forms such as micro-emulsions, suspension concentrates, emulsifiable concentrates, and others.

[0018] In one embodiment, the termiticidal mixture is distributed throughout the gypsum core, ensuring protection against termites. Preferably the termiticidal mixture is homogeneously distributed throughout the gypsum core, ensuring uniform protection against termites.

[0019] Furthermore, the paper facing of the gypsum board may also be treated with the termiticidalagent. The incorporation of this termiticidal mixture provides both contact and repellent actions, effectively deterring termite infestation.

[0020] In addition to termite protection, the gypsum board exhibits enhanced mechanical properties. The inclusion of the termiticidal mixture improves properties such as core hardness and nail pull strength, with these values potentially increasing compared to untreated boards.

[0021] Another aspect of the invention provides a method for producing the termite-repellent gypsum board, which involves preparing a gypsum slurry and incorporating the termiticidal mixture into the slurry at a weight ratio of 1: 1 to 1:5. The slurry is then formed into a board and dried at temperatures between 70°C and 200°C to achieve the desired properties.

[0022] The method allows for the optimization of the gypsum board's properties, including pore size, core hardness, and nail pull strength, by adjusting the slurry composition, using accelerators, and controlling drying conditions. Additionally, the paper facing may be treated with the termiticidal agent for further protection.

[0023] This invention provides an innovative solution for improving the termite resistance of gypsum boards used in construction, offering both functional and structural benefits.

[0024] DETAILED DESCRIPTION OF THE INVENTION

[0025] The present invention will now be described more fully hereinafter. This invention may be embodied in many different forms and should not be construed as limited to the embodiments set forth herein; rather, these embodiments are provided for thoroughness and completeness, and fully convey the scope of the invention to the skilled person.

[0026] The term, ‘anti -termite gypsum board' or ‘termite-repellent gypsum board’, used herein refers to a type of gypsum board that is specifically designed to resist or prevent damage caused by termites. It typically consists of a gypsum core, which is often combined with a paper facing, and is treated or impregnated with a termiticidal mixture.

[0027] The present invention provides an anti-termite gypsum board designed to provide superior protection against termite infestations while maintaining the structural integrity of the board. The invention involves the incorporation of a termiticidal mixture within die gypsum core of the board, making it resistant to termite damage throughout its entire structure, including thetypically vulnerable paper facings. This novel approach significantly enhances the durability and lifespan of gypsum boards, particularly in termite-prone areas.

[0028] Said gypsum board of the present invention comprises a gypsum core, a paper or a glass fibre facing, and a termiticidal mixture integrated within the gypsum core. The termiticidal mixture consists of a termiticidal agent and a foaming agent.

[0029] The core is the primary structural element of the board and is made of standard gypsum material, providing the board with its mechanical strength and rigidity'. The paper or glass fibre facing provides additional structural support and serves as a protective barrier for the gypsum core.

[0030] In an embodiment of the present invention, the termiticidal mixture comprises a termiticidal agent and a foaming agent in a ratio ranging from 1:1 to 1:5. This specific ratio ensures that the termite-repellent properties of the termiticidal agent are effectively delivered throughout the gypsum board while the foaming agent aids in creating a desirable pore structure within the gypsum core. The incorporation of the foaming agent in the said ratio range also enhances the board's overall mechanical strength, such as hardness and nail pull resistance, while maintaining the termite resistance provided by the termiticidal agent. This balance between the termiticidal agent and foaming agent ensures both effective protection against termites and optimal performance of the gypsum board in construction applications.

[0031] In an embodiment of the present invention, the termiticidal agent is not limited to bifenthrin. Other termiticidal agents that may be used include, but are not limited to, fipronil, imidacloprid, chlorpyrifos, deltamethrin, or any other chemical compound with proven efficacy in repelling or killing termites. These agents can be used in various forms, such as micro-emulsions, suspension concentrates, emulsifiable concentrates, wettable powders, or water-dispersible granules, depending on the specific formulation and desired performance characteristics of the anti-termite gypsum board. The versatility in the selection of termiticidal agents ensures the adaptability of the invention to different environmental conditions and manufacturing requirements while maintaining effective termite resistance.

[0032] In a specific embodiment of the present invention, the termiticidal agent is bifenthrin.In a specific embodiment of the present invention, the termiticidal agent is in the form of suspension concentrates (SC).

[0033] In an embodiment of the present invention, the concentration of the termiticidal agent ranges from 0.05% to 1.5%. This concentration ensures that the gypsum board retains effective antitermite properties while maintaining the structural integrity of the board. The specific concentration range provides a balance between termite resistance and the preservation of the board's physical properties, such as strength and durability. The termiticidal agent at this concentration is sufficient to deter, repel, or eliminate termites, depending on the type of agent used, ensuring long-lasting protection for the gypsum board in termite-prone areas.

[0034] In an embodiment of the present invention, the foaming agent included in the termiticidal mixture is selected from various surfactants such as sodium lauryl ether sulfate (SLES), alpha olefin sulfonate (AOS), fatty acid salts, cocamidopropyl betaine, lauryl glucoside, or a combination thereof. These foaming agents help achieve the desired pore structure within the gypsum, which enhances the mechanical strength and resistance to termites. The ratio of the termiticidal agent to the foaming agent is typically in the range of 1: 1 to 1: 5, ensuring both effective termite resistance and optimal mechanical performance.

[0035] In one embodiment of the invention, the termiticidal mixture is distributed throughout the gypsum core. Preferably the termiticidal mixture is homogeneously distributed throughout the gypsum core, this ensures uniform protection against termites throughout the entire board, contributing to consistent physical properties such as strength and hardness across the entire surface area of the gypsum board.

[0036] In addition to the gypsum core treatment, the paper facing of the gypsum board is optionally treated with the termiticidal agent. This added treatment provides an additional layer of protection for the board, particularly because paper facings are often highly susceptible to termite damage. The treatment of the paper facing ensures that termites are deterred not only from the core but also from attacking the external layers of the board.

[0037] The incorporation of the termiticidal mixture into the gypsum board significantly enhances its mechanical properties. The foaming agent used in the termiticidal mixture helps to form pores within the gypsum core. These pores contribute to the board's lightweight structure and improved insulation properties while maintaining core hardness and nail pull strength.In one embodiment of the invention, the core hardness of the gypsum board, which typically ranges from 60 to 120 Newtons (N), is improved by up to 10% compared to a board without the termiticidal mixture. This enhancement in core hardness is achieved through the integration of the termiticidal mixture, which not only provides anti-termite properties but also contributes to the overall structural integrity of the board. The improved hardness increases the board's resistance to physical damage, enhancing its performance in various construction applications.

[0038] In one embodiment of the invention, the nail pull resistance of the board, which typically ranges from 230 to 370 Newtons (N), is also increased by up to 10% compared to untreated boards. This improvement in nail pull strength is a result of the incorporation of the termiticidal mixture, which enhances the overall mechanical properties of the board. These enhanced properties contribute to the board's resilience and durability, making it suitable for use in construction projects where termite protection, as well as structural integrity, is crucial. The increased nail pull strength ensures the board's performance remains reliable in demanding applications, further extending its lifespan and reducing the need for repairs.

[0039] In an embodiment of the present invention, the board with the termiticidal mixture in the core has a pore size ranging from 500 to 800 μm. This specific pore size range is carefully controlled to optimize the distribution of the termiticidal agent throughout the gypsum core. The controlled pore size not only helps in evenly dispersing the termiticide but also contributes to the board's overall mechanical properties, such as hardness and nail pull strength. Additionally, the porosity aids in enhancing the effectiveness of the termiticidal mixture by allowing for better interaction with termites, further improving the board's resistance to termite damage. In a specific embodiment of the present invention, the board with the termiticidal mixture in the core has a pore size ranging from 500 to 690 μm.

[0040] The present invention further provides a method of producing the termite-repellent gypsum board, which involves preparing a gypsum slurry by mixing gypsum powder with water and other necessary ingredients, creating a base for shaping the gypsum board. The termiticidal mixture, which includes a termiticidal agent and a foaming agent in a ratio of 1: 1 to 1:5, is then added to the slurry. The mixture is thoroughly blended into the slurry to ensure distribution of the termiticidal agent throughout the board. Once the slurry is well-mixed, it is poured onto a first paper or glass fibre facing moving along on a conveyor belt, followingwhich a second facing is applied on top of the slurry and this structure is passed through an extruder which ensures the board is the desired thickness.

[0041] The formed gypsum board is then subjected to a drying process at a temperature ranging from 70°C to 200°C. This drying step is crucial for achieving the appropriate physical properties, such as core hardness and mechanical strength, while also preserving the stability and effectiveness of the termiticidal agent. Additionally, the process allows for optimization of the board’s properties. By adjusting the amount of accelerator used in the slurry, pore size can be controlled, and by modifying the water gauge, the texture and strength of the final board can be fine-tuned. These adjustments ensure that the resulting gypsum board maintains both its termite-resistant qualities and its mechanical performance for a range of construction applications.

[0042] In a specific embodiment of the invention, the accelerator used is a heat-resistant accelerator (HRA), which allows the board to maintain its properties even under higher temperature conditions during the drying process.

[0043] In an embodiment of the present invention, the slurry comprises a termiticidal agent in the form of a termiticidal formulation in an amount ranging from 0.01 to 7 wt% relative to stucco. In a specific embodiment of the present invention, the termiticidal formulation is present in an amount ranging from 0.1 to 3.4 wt% relative to stucco. In an embodiment of the present invention, the method of producing the termite-repellent gypsum board involves optionally treating the paper facing of the gypsum board with a termiticidal agent, in addition to the termite-resistant treatment applied to the gypsum core. This approach provides comprehensive protection against termite infestation, ensuring that both the core and the paper facing are resistant to termite damage, thereby enhancing the overall durability and effectiveness of the gypsum board in termite-prone environments.

[0044] The invention offers a cost-effective solution for producing termite-resistant gypsum boards. By integrating the termiticidal mixture directly into the gypsum core during manufacturing, the need for additional termite treatments after installation is reduced. This reduces long-term maintenance costs associated with termite infestations and the need for repairs or replacements. Furthermore, the invention contributes to sustainable construction practices. By improving the durability and termite resistance of gypsum boards, the need for frequent board replacements is minimized, resulting in reduced waste and longer-lasting building materials.EXAMPLES

[0045] Example 1 (Using Flash Calcination)

[0046] Preparation of the termite repellent gypsum board

[0047] A gypsum slurry was prepared by mixing gypsum powder with water and other necessary ingredients. This slurry served as the base for forming the gypsum board. The termiticidal mixture, as detailed in Table 1, which included bifenthrin and a foaming agent, was then incorporated into the slurry. The foaming agent was sodium lauryl ether sulfate (SLES). The foaming agent was added in a controlled amount to create the desired pore structure within the gypsum core. The termiticidal agent was uniformly distributed throughout the slurry to ensure consistent protection against termites. The slurry was then poured into a mold, and the gypsum board was shaped into the desired dimensions. After the board was formed, it was dried at a temperature between 70°C and 200°C, resulting in a termite-repellent gypsum board.

[0048] Table 1: Termiticidal mixture in the gypsum board

[0049] Samples Wt% of Termiticidal Mixture

[0050] bifenthrin

[0051] formulation

[0052] relative to Wt% of Bifenthrin Wt% of SLES Ratio stucco relative to slurry relative to slurry

[0053] Comparative Nil Nil 0.024 NA Example 1

[0054] Inventive 0.4 0.019 0.066 1:3.5 Example 1

[0055] Inventive 0.5 0.02 0.04 1:2

[0056]

[0057] Example 2

[0058] Anti-termite efficacy results:

[0059] Each sample was packed in a porous plastic pouch with a 0.5-meter long wire attached to the pouch, with aluminum number tags placed on the other end for identification. The samples were labeled as described above and placed in termite mounds. These termite mounds (TM) were fixed in a lab setup where the temperature was maintained at 28°C for a period of 90 days. A total of four termite mounds were used, each consisting of test samples alongside control samples for evaluating the termite-resistant properties of the test samples. Thebiocidal boards containing a termiticidal agent at two different concentrations and plain board were used in the study.

[0060] Subterranean termites were introduced into the mounds, where they were strongly attracted to the stations. It was assumed that the termites would primarily attack samples that were not resistant to termite infestation. The absolute weights of each exposed cut piece were recorded, and the percent weight difference was calculated by comparing the initial weights to the final weights after exposure.

[0061] The statistical difference between the initial and final weights of the samples was determined through analysis of variance. Observations of termite damage, such as marks, nibbling, scraping, pitting, and perforations, were recorded and analyzed using digital imaging techniques.

[0062] Based on the observed results, an appropriate rating, indicating the degree of damage, was assigned to the samples. The ratings, which were based on ASTM D3345 with modifications, were detailed in Table 2. The ratings, ranging from 1 to 10, provide a quantitative measure of the materials' resistance to termite attack, with higher ratings indicating greater resistance.

[0063] Table: Termite Resistance Rating Scale for Test Samples Based on ASTM D3345 (Modified) Samples Rating

[0064] Comparative Example 1 8

[0065] (Plain board)

[0066] Inventive Example 1 9

[0067] Inventive Example 2 9.7

[0068]

[0069] The termite resistance test results revealed several key findings. The Plain Board (comparative example 1), with a rating of 8, showed significant termite activity, with pinsized holes indicating the presence of termites. Its low rating reflects the high cellulose content, which makes it susceptible to termite damage. The 0.4% Termiticidal Board (inventive example 1) received a rating of 9, with no visible termite damage, demonstrating that even a low concentration of termiticidal chemicals provides effective protection against termites. The 0.5% Termiticidal Board achieved (inventive example 2) the highest rating of 9.7, showing no signs of termite attack, suggesting that increasing the concentration of termiticidal agent further enhances the material’s resistance. In summary, the 0.5%termiticidal board was found to provide the most effective termite resistance with a rating of 9.7, while plain board received the lowest ratings, emphasizing the critical role of chemical treatments in termite resistance.

[0070] Mechanics of boards

[0071] The mechanical properties of boards with and without termiticidal mixture were compared using test methods according to ASTM C473 and ASTM C1860 standards. Quality tests demonstrated improvements in the mechanical properties of boards with termiticidal mixture. Table 3: Mechanical Properties of Gypsum Boards with Termiticidal Mixture

[0072] Samples Core Hardness Nail Pull Resistance

[0073] Comparative Example 1 66 N 259 N

[0074] Inventive Example 1 58 N 262 N

[0075] Inventive Example 2 69 N 265 N

[0076]

[0077] Surprisingly, Table 3 clearly shows that the board with the termiticidal mixture exhibited improved strength compared to the plain board. Specifically, the core hardness of the board containing the termiticidal mixture increased by 4.5%. Similarly, the nail pull resistance for the board with the termiticidal mixture was increased by 2%. Therefore, as shown in both Table 2 and Table 3, the gypsum board with the termiticidal mixture in the core not only provides protection against termite infestation but also significantly enhances the board's strength in terms of core hardness and nail pull resistance.

[0078] Example 2 (Using Fluidized Chamber Calcination)

[0079] Preparation of the termite repellent gypsum board

[0080] A gypsum slurry was prepared by mixing gypsum powder with water and other necessary ingredients. This slurry served as the base for forming the gypsum board. The termiticidal mixture, as detailed in Table 4, which included bifenthrin and a foaming agent, was then incorporated into the slurry. The foaming agent was sodium lauryl ether sulfate (SLES). The foaming agent was added in a controlled amount to create the desired pore structure within the gypsum core. The termiticidal agent was uniformly distributed throughout the slurry to ensure consistent protection against termites. The slurry was then poured into a mold, and the gypsum board was shaped into the desired dimensions. After the board was formed, it wasdried at a temperature between 70°C and 200°C, resulting in a termite-repellent gypsum board.

[0081] Table 4: Termiticidal mixture in the gypsum board

[0082] Samples Wt% of Termiticidal Mixture

[0083] bifenthrin

[0084] formulation

[0085] relative to Wt% of Bifenthrin Wt% of SLES Ratio stucco relative to slurry relative to slurry

[0086] Comparative Nil Nil 0.024 NA Example 2

[0087] Inventive 0.5 0.019 0.034 1:1.8 Example 3

[0088] Inventive 0.7 0.03 0.034 1:1.1

[0089]

[0090] Example 4

[0091] Anti-termite efficacy results:

[0092] Each sample was packed in a porous plastic pouch with a 0.5-meter-long wire attached to the pouch, with aluminium number tags placed on the other end for identification. The samples were labelled as described above and placed in termite mounds. These termite mounds (TM) were fixed in a lab setup where the temperature was maintained at 28°C for a period of 90 days. A total of four termite mounds were used, each consisting of test samples alongside control samples for evaluating the termite-resistant properties of the test samples. The biocidal boards containing a termiticidal agent at two different concentrations and plain board were used in the study.

[0093] Subterranean termites were introduced into the mounds, where they were strongly attracted to the stations. It was assumed that the termites would primarily attack samples that were not resistant to termite infestation. The absolute weights of each exposed cut piece were recorded, and the percent weight difference was calculated by comparing the initial weights to the final weights after exposure.

[0094] The statistical difference between the initial and final weights of the samples was determined through analysis of variance. Observations of termite damage, such as marks, nibbling, scraping, pitting, and perforations, were recorded and analysed using digital imaging techniques.Based on the observed results, an appropriate rating, indicating the degree of damage, was assigned to the samples. The ratings, which were based on ASTM D3345 with modifications, were detailed in Table 5. The ratings, ranging from 1 to 10, provide a quantitative measure of the materials' resistance to termite attack, with higher ratings indicating greater resistance.

[0095] Table 5: Termite Resistance Rating Scale for Test Samples Based on ASTM D3345 (Modified)

[0096] Samples Rating

[0097] Comparative Example 2 8

[0098] (Plain board)

[0099] Inventive Example 3 9.5

[0100] Inventive Example 4 10

[0101]

[0102] The termite resistance test results revealed several key findings. The Plain Board (comparative example 1), with a rating of 8, showed significant termite activity, with pinsized holes indicating the presence of termites. Its low rating reflects the high cellulose content, which makes it susceptible to termite damage. The 0.5% Termiticidal Board (inventive example 3) received a rating of 9.5, with no visible termite damage, demonstrating that even a low concentration of termiticidal chemicals provides effective protection against termites. The 0.7% Termiticidal Board achieved (inventive example 4) a rating of 10, showing no signs of termite attack, suggesting that increasing the concentration of termiticidal agent further enhances the material’s resistance. In summary, the 0.5% and 0.7% termiticidal boards were found to provide the most effective termite resistance with a rating up to 10, while plain board received the lowest ratings, emphasizing the critical role of chemical treatments in termite resistance.

[0103] Mechanics of boards

[0104] The mechanical properties of boards with and without termiticidal mixture were compared using test methods according to ASTM C473 and ASTM C1860 standards. Quality tests demonstrated improvements in the mechanical properties of boards with termiticidal mixture.Table 6: Mechanical Properties of Gypsum Boards with Termiticidal Mixture Samples Core Hardness Nail Pull Resistance

[0105] Comparative Example 2 107 N 330 N

[0106] Inventive Example 3 108 N 354 N

[0107] Inventive Example 4 110 N 349 N

[0108]

[0109] Surprisingly, Table 6 clearly shows that the board with the termiticidal mixture exhibited improved strength compared to the plain board. Specifically, the core hardness and the nail pull resistance for the board increased with the addition of termicidal mixture. Therefore, as shown in both Table 5 and Table 6, the gypsum board with the termiticidal mixture in the core not only provides protection against termite infestation but also significantly enhances the board's strength in terms of core hardness and nail pull resistance.

[0110] The termite-repellent gypsum board of the present invention has significant industrial applicability in the construction and building materials industry. Due to its enhanced termiteresistant properties, the gypsum board can be widely utilized in the construction of residential, commercial, and industrial buildings, particularly in regions prone to termite infestations. This innovative product provides an effective solution for protecting buildings from termite damage, which is a major concern in areas with high termite activity.

[0111] The incorporation of a termiticidal agent, such as bifenthrin, into the gypsum board ensures long-lasting protection without compromising the structural integrity or performance of the board. The addition of a foaming agent further enhances the physical properties of the gypsum board, improving its mechanical strength, core hardness, and nail pull strength. This makes the board suitable for a wide range of applications where durability and resistance to pest damage are crucial.

[0112] In addition to its use in walls and ceilings, the termite-repellent gypsum board can be employed in flooring, insulation, and other building components that require protection against termites. Furthermore, the method for producing this board, which involves integrating the termiticidal mixture into the gypsum slurry, is scalable and compatible with existing gypsum board manufacturing processes, making it a cost-effective solution for large-scale production.Overall, the termite-repellent gypsum board addresses a critical need in the construction industry, offering a reliable, durable, and environmentally friendly solution to combat termite damage and improve the longevity of buildings.

Claims

CLAIMS1. A gypsum board comprising:(i) a gypsum core;(ii) a paper or glass fibre facing; and(iii) a termiticidal mixture comprising a termiticidal agent and a foaming agent in a ratio ranging from 1: 1 to 1: 5, integrated within the gypsum core, wherein the termiticidal mixture imparts anti-termite properties to the gypsum board.

2. The gypsum board as claimed in claim 1, wherein the termiticidal agent is in the form of micro-emulsions, suspension concentrates, emulsifiable concentrates, wettable powders, water dispersible granules, capsule suspensions, emulsifiable granules, or combinations thereof.

3. The gypsum board as claimed in claim 1, wherein the termiticidal agent is in the form of suspension concentrates (SC).

4. The gypsum board as claimed in claim 1, wherein the termiticidal agent is bifenthrin.

5. The gypsum board as claimed in claim 1, wherein the termiticidal mixture is distributed throughout the gypsum core.

6. The gypsum board as claimed in claim 1, wherein the facing is a paper-based facing.

7. The gypsum board as claimed in claim 1, wherein the paper facing is treated with the termiticidal agent.

8. The gypsum board as claimed in claim 1, wherein the termiticidal agent provides a contact / repellent action that deters termite infestation.

9. The gypsum board as claimed in claim 1, wherein the foaming agent is selected from the group consisting of sodium lauryl ether sulfate (SLES), alpha olefin sulfonate (AOS), fatty acid salts, cocamidopropyl betaine, lauryl glucoside, ammonium lauryl sulfate, sodium dodecylbenzenesulfonate (SDBS) or a combination thereof.

10. The gypsum board as claimed in claim 1, wherein the board with termiticidal mixture in the core has a pore size ranging from 500–800 μm.

11. The gypsum board as claimed in claim 1, wherein the board with termiticidal mixture in the core has a core hardness ranging from 60 to 120N.

12. The gypsum board as claimed in claim 11, wherein the board with termiticidal mixture in the core has a core hardness which is increased by up to 10% compared to a board without termiticidal mixture.

13. The gypsum board as claimed in claim 9, wherein the board with termiticidal mixture in the core has a nail pull strength ranging from 230 to 370N.

14. The gypsum board as claimed in claim 13, wherein the board with termiticidal mixture in the core has a nail pull strength which is increased by up to 10% compared to a board without termiticidal mixture.

15. A method for producing a termite-repellent gypsum board, comprising the steps of:(i) preparing a gypsum slurry;(ii) incorporating a termiticidal mixture comprising a termiticidal agent and a foaming agent into the gypsum slurry;(iii) forming the gypsum slurry into a board; and(iv) drying the gypsum board at a temperature between 70°C and 200°C, resulting in a gypsum board with anti-termite properties.

16. The method for producing a termite-repellent gypsum board as claimed in claim 15, wherein the termiticidal mixture comprising a termiticidal agent and a foaming agent is added to the gypsum slurry at a ratio of 1: 1 to 1:5, by weight.

17. The method for producing a termite-repellent gypsum board as claimed in claim 15, wherein the termiticidal agent is bifenthrin.

18. The method for producing a termite-repellent gypsum board as claimed in claim 15, wherein the termiticidal mixture is stable during drying at temperatures greater than 180°C.

19. The method for producing a termite-repellent gypsum board as claimed in claim 15, wherein the pore size in said gypsum boards is analysed and the slurry composition is optimized by adjusting the amount of accelerator, and the water gauge to achieve a target pore size.

20. The method for producing a termite-repellent gypsum board as claimed in claim 19, wherein the accelerator is a heat-resistant accelerator (HRA).

21. The method for producing a termite-repellent gypsum board as claimed in claim 15, wherein the paper facing of the gypsum board is optionally treated with termiticidal agent, in addition to termite-resistant treatment of the gypsum core.

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