High-strength flame-retardant bus duct and preparation method thereof

Abstract

The application relates to a high-strength flame-retardant bus duct and a preparation method thereof, and relates to the technical field of high polymer materials.The high-strength flame-retardant bus duct comprises a bus and a cast resin layer located on at least part of the surface of the bus, and the cast resin layer comprises the following components: a resin base, a filler, a curing agent and an additive.Compared with the prior art, the application mainly uses a prepolymer of phenolic resin, bismaleimide resin and benzoxazine resin in a suitable proportion as the resin base, and adds zirconium diboride filler which is surface-coated and modified by a specific first silane coupling agent and a specific second silane coupling agent, so that the mechanical strength of the material after high-humidity and high-heat aging is significantly improved, a bus duct with high strength and excellent flame-retardant performance is obtained, and long-term stable operation under harsh service environments such as high temperature and high humidity is met, and operation safety is improved.

Description

Technical Field

[0001] This invention relates to the field of polymer materials technology, and in particular to a high-strength flame-retardant busbar trunking and its preparation method. Background Technology

[0002] Busbar trunking, as a key power transmission and distribution system, is widely used in industrial plants, commercial buildings, data centers, and other scenarios, undertaking the task of transmitting high-current, high-power electrical energy. With the continuous expansion of application scenarios, the demand for long-term stable operation of busbar trunking in harsh service environments such as high temperature and high humidity is becoming increasingly prominent, placing higher requirements on its structural strength and flame-retardant performance.

[0003] Currently, the insulation and protection of busbar trunking typically involves coating the busbars with a cast resin layer. This resin layer usually uses thermosetting resins such as epoxy resin, polyester resin, or phenolic resin as the matrix, supplemented with various inorganic fillers to improve overall performance. However, existing cast resin layers are prone to moisture absorption and aging under high temperature and humidity environments, leading to a significant decrease in mechanical strength and making it difficult to meet the increasingly stringent requirements of power systems for equipment safety and reliability. Summary of the Invention

[0004] To address the above problems, this invention provides a high-strength flame-retardant busbar trunking and its preparation method.

[0005] In a first aspect, the present invention provides a high-strength flame-retardant busbar trunking, comprising a busbar and a casting resin layer located on at least a portion of the surface of the busbar, the casting resin layer comprising the following components: resin base material, filler, curing agent and additives; The resin base material is composed of a prepolymer of phenolic resin, bismaleimide resin and benzoxazine resin in a mass ratio of 100:(9-17). The filler includes modified zirconium diboride, at least a portion of the surface of which has a first silane coupling agent and a second silane coupling agent, the first silane coupling agent having a perfluoroalkyl chain with 4-8 carbon atoms, and the second silane coupling agent having an epoxycyclohexyl group.

[0006] Furthermore, the mass ratio of the phenolic resin to the bismaleimide benzoxazine prepolymer is 100:15.5.

[0007] Furthermore, the method for preparing the prepolymer of the bismaleimide resin and benzoxazine resin includes the following steps: The bismaleimide resin was heated to a molten state, and then benzoxazine resin was added to carry out a prepolymerization reaction. After cooling to room temperature, the bismaleimide benzoxazine prepolymer was obtained. The mass ratio of the bismaleimide resin to the benzoxazine resin is (0.5-0.8):(1.0-1.2), and the prepolymerization reaction conditions include: temperature of 150-160℃ and time of 1.5-2.5h.

[0008] Furthermore, the preparation method of the modified zirconium diboride includes the following steps: Zirconium diboride, the first silane coupling agent, and the second silane coupling agent were added to a mixed solvent of ethanol and water with a pH of 4.5-5.5 and heated and stirred. The mixture was then filtered, dried, and ground to obtain the modified zirconium diboride. The mass ratio of zirconium diboride, the first silane coupling agent, and the second silane coupling agent is 100:(3-5):(1.5-2). The heating and stirring conditions include a temperature of 55-65℃ and a time of 60-90 min. The grinding conditions include a grinding speed of 50-100 rpm and a grinding time of 30-40 min.

[0009] Furthermore, the first silane coupling agent comprises at least one of perfluorobutylethyltrichlorosilane, perfluorohexylethyltrimethoxysilane, and perfluorooctyltrimethoxysilane, and the second silane coupling agent comprises 2-(3,4-epoxycyclohexyl)ethyltrimethoxysilane.

[0010] Furthermore, by weight, the high-strength flame-retardant busbar trunking comprises the following components: 95-110 parts of the resin base, 30-40 parts of the filler, 20-25 parts of the curing agent, and 3-7 parts of the additives.

[0011] Further, the curing agent comprises hexamethylenetetramine and an imidazole accelerator in a mass ratio of (8-12):1, wherein the imidazole accelerator comprises at least one of 2-methylimidazole and 2-ethyl-4-methylimidazole.

[0012] Furthermore, the additives include a lubricant and an antifoaming agent in a mass ratio of (3-5):1, wherein the lubricant includes at least one of zinc stearate and magnesium stearate, and the antifoaming agent includes an organosilicon antifoaming agent.

[0013] Secondly, the present invention provides a method for preparing the high-strength flame-retardant busbar trunking as described in any one of the first aspects, such as... Figure 1 As shown, it includes the following steps: The resin base, filler, curing agent and additives are mixed evenly to obtain the casting resin; The busbar is placed in the mold, then the casting resin is added for curing, cooled and demolded to obtain the high-strength flame-retardant busbar trough.

[0014] Furthermore, the curing conditions include: pressure of 10-13 MPa, temperature of 155-160°C, and time of 2.5-3.5 h.

[0015] The technical solutions provided in the embodiments of the present invention have at least the following advantages compared with the prior art: This invention provides a high-strength flame-retardant busbar trunking and its preparation method. Compared with the prior art, this invention mainly uses a prepolymer of phenolic resin, bismaleimide resin, and benzoxazine resin in appropriate proportions as the resin base, and adds zirconium diboride filler that has been surface-modified by specific first and second silane coupling agents. This significantly improves the mechanical strength of the material after high humidity and high heat aging, resulting in a busbar trunking with both high strength and excellent flame-retardant properties. This allows for long-term stable operation in harsh service environments such as high temperature and high humidity, improving operational safety. Specifically: 1) Resin base system This invention uses phenolic resin as the main component. Its abundant rigid benzene ring structure and high cross-linking characteristics provide the material with excellent mechanical rigidity and a certain degree of intrinsic flame retardancy. A prepolymer of bismaleimide resin and benzoxazine resin is introduced as a modifying component. By utilizing the imide ring structure of bismaleimide resin and the Mannich bridge structure of benzoxazine resin, the brittleness of phenolic resin is alleviated and the heat resistance and hydrolytic stability of the system are improved, laying the foundation for resistance to damp heat aging.

[0016] 2) Modified zirconium diboride filler Zirconium diboride, as a high-temperature ceramic phase filler, possesses high melting point, high hardness, and excellent thermal conductivity. It can bear the main load during operation and provide a flame-retardant synergistic effect. Simultaneously, its high thermal conductivity facilitates rapid heat dissipation during busbar operation, reducing localized temperature rise. More importantly, this invention utilizes a first silane coupling agent containing a 4-8 carbon perfluoroalkyl chain and a second silane coupling agent containing an epoxy cyclohexyl group for synergistic surface coating modification. This not only imparts excellent hydrophobicity to the filler surface but also provides a certain degree of chain segment flexibility and spatial buffering. This effectively alleviates the mismatch in thermal expansion coefficients between resin curing shrinkage and ceramic filler rigidity, reduces interfacial residual stress, enhances the overall compatibility and stability of the material, and further ensures the mechanical strength of the material after high humidity and high heat aging. Thus, a busbar trunking material with both high strength and excellent flame-retardant properties is obtained. Attached Figure Description

[0017] The accompanying drawings, which are incorporated in and form part of this specification, illustrate embodiments consistent with the invention and, together with the description, serve to explain the principles of the invention.

[0018] To more clearly illustrate the technical solutions in the embodiments of the present invention or the prior art, the drawings used in the description of the embodiments or the prior art will be briefly introduced below. Obviously, for those skilled in the art, other drawings can be obtained based on these drawings without creative effort.

[0019] Figure 1 This is a schematic flowchart illustrating the preparation method of the high-strength flame-retardant busbar trunking provided in an embodiment of the present invention. Detailed Implementation

[0020] To make the objectives, technical solutions, and advantages of the embodiments of the present invention clearer, the technical solutions of the embodiments of the present invention will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only some embodiments of the present invention, not all embodiments. Based on the embodiments of the present invention, all other embodiments obtained by those skilled in the art without creative effort are within the scope of protection of the present invention.

[0021] Unless otherwise specified, all raw materials, reagents, instruments, and equipment used in this invention can be purchased commercially or prepared using existing methods. For example, in the high-strength flame-retardant busbar trunking and its preparation method provided in the embodiments of this invention, unless otherwise specified or limited, the raw materials used can be commercially available products; at the same time, unless otherwise specified or limited, the process steps and parameters involved can be carried out according to the preparation process disclosed in the prior art or using existing equipment and conventional operating methods.

[0022] The present invention will be further illustrated below with reference to specific embodiments. It should be understood that these embodiments are for illustrative purposes only and are not intended to limit the scope of the invention. Experimental methods in the following embodiments, unless otherwise specified, are generally performed according to national standards. If no corresponding national standard exists, then generally accepted international standards, conventional conditions, or conditions recommended by the manufacturer are followed.

[0023] Example 1 This example provides a high-strength flame-retardant busbar trunking, which, by weight, comprises the following components: 100 parts resin base, 36 parts filler, 23 parts curing agent and 5 parts additives; The resin base material is composed of phenolic resin (product model Durez 33446) and a prepolymer of bismaleimide resin and benzoxazine resin in a mass ratio of 100:15.5. The preparation method of the prepolymer of bismaleimide resin and benzoxazine resin includes the following process: heating bismaleimide resin (CAS No. 13676-54-5) to a molten state, and then adding benzoxazine resin (specifically bisphenol A type benzoxazine resin) in a mass ratio of bismaleimide resin to benzoxazine resin of 0.7:1.1 to carry out a prepolymerization reaction at a temperature of 155°C for 2.0 h, and cooling to room temperature to obtain the bismaleimide benzoxazine prepolymer. The filler is modified zirconium diboride, and its preparation method includes the following process: zirconium diboride, a first silane coupling agent (specifically perfluorohexylethyltrimethoxysilane), and a second silane coupling agent (specifically 2-(3,4-epoxycyclohexyl)ethyltrimethoxysilane) are added to a mixed solvent of ethanol and water at pH 5.0 in a mass ratio of 100:4:1.8 (prepared by mixing water and ethanol in a volume ratio of 2:1 and then adding an appropriate amount of glacial acetic acid to adjust the pH to 5.0; the weight of the mixed solvent added is 5 times that of zirconium diboride). The mixture is heated and stirred at 60°C and 500 rpm for 80 min, then washed with anhydrous ethanol, filtered, and dried. The resulting solid is ground at 85 rpm for 35 min to obtain the modified zirconium diboride. The curing agent is composed of hexamethylenetetramine and an imidazole accelerator (specifically 2-ethyl-4-methylimidazolium) in a mass ratio of 10:1; The additive is composed of a lubricant and a defoamer in a mass ratio of 4:1. The lubricant is zinc stearate, and the defoamer is an organosilicon defoamer (product model BYK-093).

[0024] The preparation method of the above-mentioned high-strength flame-retardant busbar trunking includes the following steps: The resin base, filler, curing agent and additives are mixed evenly to obtain the casting resin; The busbar is placed in the mold, and then the casting resin is added for curing treatment at a pressure of 12 MPa, a temperature of 158°C, and a time of 3.0 h. After cooling and demolding, the high-strength flame-retardant busbar trough is obtained.

[0025] Example 2 This example provides a high-strength flame-retardant busbar trunking, which, by weight, comprises the following components: 95 parts resin base, 30 parts filler, 20 parts curing agent and 3.8 parts additives; The resin base material is composed of a phenolic resin (product model Durez 33446) and a prepolymer of bismaleimide resin and benzoxazine resin in a mass ratio of 100:9. The preparation method of the prepolymer of bismaleimide resin and benzoxazine resin includes the following process: heating bismaleimide resin (CAS No. 13676-54-5) to a molten state, and then adding benzoxazine resin (specifically bisphenol A type benzoxazine resin) in a mass ratio of bismaleimide resin to benzoxazine resin of 0.5:1.1 to carry out a prepolymerization reaction at a temperature of 155°C for 2.0 h, and cooling to room temperature to obtain the bismaleimide benzoxazine prepolymer. The filler is modified zirconium diboride, and its preparation method includes the following process: zirconium diboride, a first silane coupling agent (specifically perfluorobutylethyltrichlorosilane), and a second silane coupling agent (specifically 2-(3,4-epoxycyclohexyl)ethyltrimethoxysilane) are added to a mixed solvent of ethanol and water at pH 5.0 in a mass ratio of 100:3:1.5 (prepared by mixing water and ethanol in a volume ratio of 2:1 and then adding an appropriate amount of glacial acetic acid to adjust the pH to 5.0; the weight of the mixed solvent added is 5 times that of zirconium diboride). The mixture is heated and stirred at 60°C and 500 rpm for 80 min, then washed with anhydrous ethanol, filtered, and dried. The resulting solid is ground at 85 rpm for 35 min to obtain the modified zirconium diboride. The curing agent is composed of hexamethylenetetramine and an imidazole accelerator (specifically 2-methylimidazole) in a mass ratio of 8:1. The additive is composed of a lubricant and a defoamer in a mass ratio of 5:1. The lubricant is zinc stearate, and the defoamer is an organosilicon defoamer (product model BYK-093).

[0026] The preparation method of the above-mentioned high-strength flame-retardant busbar trunking includes the following steps: The resin base, filler, curing agent and additives are mixed evenly to obtain the casting resin; The busbar is placed in the mold, and then the casting resin is added for curing treatment at a pressure of 10 MPa, a temperature of 160°C, and a time of 3.0 h. After cooling and demolding, the high-strength flame-retardant busbar trough is obtained.

[0027] Example 3 This example provides a high-strength flame-retardant busbar trunking, which, by weight, comprises the following components: 110 parts resin base, 40 parts filler, 25 parts curing agent and 6 parts additives; The resin base material is composed of phenolic resin (product model Durez 33446) and a prepolymer of bismaleimide resin and benzoxazine resin in a mass ratio of 100:17. The preparation method of the prepolymer of bismaleimide resin and benzoxazine resin includes the following process: heating bismaleimide resin (CAS No. 13676-54-5) to a molten state, and then adding benzoxazine resin (specifically bisphenol A type benzoxazine resin) in a mass ratio of bismaleimide resin to benzoxazine resin of 0.7:1.2 to carry out a prepolymerization reaction at a temperature of 155°C for 2.0 h, and cooling to room temperature to obtain the bismaleimide benzoxazine prepolymer. The filler is modified zirconium diboride, and its preparation method includes the following steps: zirconium diboride, a first silane coupling agent (specifically perfluorooctyltrimethoxysilane), and a second silane coupling agent (specifically 2-(3,4-epoxycyclohexyl)ethyltrimethoxysilane) are added to a mixed solvent of ethanol and water at pH 5.0 in a mass ratio of 100:3:1.5 (prepared by mixing water and ethanol in a volume ratio of 2:1 and then adding an appropriate amount of glacial acetic acid to adjust the pH to 5.0; the weight of the mixed solvent added is 5 times that of zirconium diboride). The mixture is heated and stirred at 60°C and 500 rpm for 80 min, then washed with anhydrous ethanol, filtered, and dried. The resulting solid is ground at 85 rpm for 35 min to obtain the modified zirconium diboride. The curing agent is composed of hexamethylenetetramine and an imidazole accelerator (specifically 2-methylimidazole) in a mass ratio of 12:1; The additive is composed of a lubricant and a defoamer in a mass ratio of 3:1. The lubricant is zinc stearate, and the defoamer is an organosilicon defoamer (product model BYK-093).

[0028] The preparation method of the above-mentioned high-strength flame-retardant busbar trunking includes the following steps: The resin base, filler, curing agent and additives are mixed evenly to obtain the casting resin; The busbar is placed in the mold, and then the casting resin is added for curing treatment at a pressure of 13 MPa, a temperature of 156°C, and a time of 3.0 h. After cooling and demolding, the high-strength flame-retardant busbar trough is obtained.

[0029] Comparative Example 1 This example provides a high-strength flame-retardant busbar trunking and its preparation method, which differs from Example 1 only in that: (1) All resin base materials are phenolic resins in Example 1 (i.e., prepolymers without added bismaleimide resin and benzoxazine resin).

[0030] Comparative Example 2 This example provides a high-strength flame-retardant busbar trunking and its preparation method, which differs from Example 1 only in that: (1) All the silane coupling agents used in the modified zirconium diboride are the first silane coupling agent in Example 1 (i.e. no second silane coupling agent was added).

[0031] Comparative Example 3 This example provides a high-strength flame-retardant busbar trunking and its preparation method, which differs from Example 1 only in that: (1) All the silane coupling agents used in the modified zirconium diboride are the second silane coupling agent in Example 1 (i.e., no first silane coupling agent was added).

[0032] Test case In this example, the cured casting resins from Examples 1-3 and Comparative Examples 1-3 were processed into test samples of uniform size. After aging under high temperature and high humidity conditions of 50℃ and 85% RH for 7 days, the samples were subjected to tensile strength tests according to GB / T 2567-2021, and the test results are shown in Table 1.

[0033] Table 1 Based on the above test results, this example further tested the limiting oxygen index of the samples in Examples 1-3 in accordance with GB / T 2406.2-2009, and the test results are shown in Table 2.

[0034] Table 2 As shown in Tables 1 and 2, compared with Comparative Examples 1-3, Examples 1-3 of the present invention have higher tensile strength after high humidity and high heat aging, while the limiting oxygen index is maintained at 35% or above, indicating that they have both high strength and excellent flame retardant properties, and can meet the requirements of long-term stable operation in harsh service environments such as high temperature and high humidity.

[0035] Various embodiments of the present invention may exist in the form of a range; it should be understood that the description in the form of a range is merely for convenience and brevity and should not be construed as a hard limitation on the scope of the invention; therefore, it should be considered that the range description has specifically disclosed all possible subranges and single numerical values ​​within that range. For example, it should be considered that the range description from 1 to 6 has specifically disclosed subranges such as from 1 to 3, from 1 to 4, from 1 to 5, from 2 to 4, from 2 to 6, from 3 to 6, etc., and single numbers within the range, such as 1, 2, 3, 4, 5, and 6, regardless of the range. Furthermore, whenever a numerical range is referred to herein, it means including any referenced number (fraction or integer) within the range referred to.

[0036] The above description is merely a specific embodiment of the present invention, enabling those skilled in the art to understand or implement the invention. Various modifications to these embodiments will be readily apparent to those skilled in the art, and the general principles defined herein may be implemented in other embodiments without departing from the spirit or scope of the invention. Therefore, the present invention is not to be limited to the embodiments shown herein, but is to be accorded the widest scope consistent with the principles and novel features claimed herein.

Claims

1. A high-strength flame-retardant busbar trunking, characterized in that, The device includes a busbar and a casting resin layer located on at least a portion of the surface of the busbar, the casting resin layer comprising the following components: resin base, filler, curing agent and additives; The resin base material is composed of a prepolymer of phenolic resin, bismaleimide resin and benzoxazine resin in a mass ratio of 100:(9-17). The filler includes modified zirconium diboride, at least a portion of the surface of which has a first silane coupling agent and a second silane coupling agent, wherein the first silane coupling agent includes at least one of perfluorobutylethyltrichlorosilane and perfluorooctyltrimethoxysilane, and the second silane coupling agent includes 2-(3,4-epoxycyclohexyl)ethyltrimethoxysilane. The preparation method of the prepolymer of bismaleimide resin and benzoxazine resin includes the following steps: The bismaleimide resin is heated to a molten state, and then benzoxazine resin is added to carry out a prepolymerization reaction. After cooling to room temperature, the prepolymer of the bismaleimide resin and benzoxazine resin is obtained.

2. The high-strength flame-retardant busbar trunking according to claim 1, characterized in that, The mass ratio of the prepolymer of the phenolic resin and the bismaleimide resin to the benzoxazine resin is 100:15.

5.

3. The high-strength flame-retardant busbar trunking according to claim 1, characterized in that, The mass ratio of the bismaleimide resin to the benzoxazine resin is (0.5-0.8):(1.0-1.2), and the prepolymerization reaction conditions include: temperature of 150-160℃ and time of 1.5-2.5h.

4. The high-strength flame-retardant busbar trunking according to claim 1, characterized in that, The preparation method of the modified zirconium diboride The process includes the following: Zirconium diboride, the first silane coupling agent, and the second silane coupling agent were added to a mixed solvent of ethanol and water with a pH of 4.5-5.5 and heated and stirred. The mixture was then filtered, dried, and ground to obtain the modified zirconium diboride. The mass ratio of zirconium diboride, the first silane coupling agent, and the second silane coupling agent is 100:(3-5):(1.5-2). The heating and stirring conditions include a temperature of 55-65℃ and a time of 60-90 min. The grinding conditions include a grinding speed of 50-100 rpm and a grinding time of 30-40 min.

5. The high-strength flame-retardant busbar trunking according to any one of claims 1-4, characterized in that, The high-strength flame-retardant busbar trunking comprises the following components by weight: 95-110 parts of the resin base, 30-40 parts of the filler, 20-25 parts of the curing agent, and 3-7 parts of the additives.

6. The high-strength flame-retardant busbar trunking according to claim 5, characterized in that, The curing agent comprises hexamethylenetetramine and an imidazole accelerator in a mass ratio of (8-12):1, wherein the imidazole accelerator comprises at least one of 2-methylimidazole and 2-ethyl-4-methylimidazole.

7. The high-strength flame-retardant busbar trunking according to claim 5, characterized in that, The additives include a lubricant and an antifoaming agent in a mass ratio of (3-5):1, wherein the lubricant includes at least one of zinc stearate and magnesium stearate, and the antifoaming agent includes an organosilicon antifoaming agent.

8. A method for preparing a high-strength flame-retardant busbar trunking according to any one of claims 1-7, characterized in that, Includes the following steps: The resin base, filler, curing agent and additives are mixed evenly to obtain the casting resin; The busbar is placed in the mold, then the casting resin is added for curing, cooled and demolded to obtain the high-strength flame-retardant busbar trough.

9. The method for preparing high-strength flame-retardant busbar trunking according to claim 8, characterized in that, The curing conditions include: pressure of 10-13 MPa, temperature of 155-160℃, and time of 2.5-3.5 h.

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