High-stability hot melt block, preparation method thereof and hot melt fuse

Abstract

The application provides a high-stability hot-melt block and a preparation method thereof and a hot-melt breaker. According to the weight percentage, the high-stability hot-melt block comprises 90-100% of N,N-bis-phthalimide ethane-3 organic matter, 0-10% of a filler, 0-1% of a lubricant, 0-2% of an adhesive and 0-2% of a pigment. The high-stability hot-melt block is prepared by taking the N,N-bis-phthalimide ethane-3 organic matter as a main material and adding appropriate amounts of the filler, the lubricant, the adhesive and the pigment. The preparation method is simple in operation and low in production cost. Compared with the hot-melt block prepared by using the heat-sensitive material phthalimide, the high-stability hot-melt block has high insulation resistance, fast operation response rate and better anti-hydration, high-temperature resistance and stability, so that the hot-melt breaker can stably work at a predetermined temperature, thereby improving the stability and reliability of the hot-melt breaker.

Description

Technical Field

[0001] This invention relates to the field of thermal fuse technology, and particularly to a highly stable thermal fuse block, its preparation method, and a thermal fuse. Background Technology

[0002] A thermal fuse, also known as a thermal circuit breaker, is a non-resettable overheat protection device. It serves as a terminal protection component for electrical appliances such as electric irons, hair dryers, electric stoves, rice cookers, electric kettles, coffee makers, and sandwich makers, providing overheat protection. Thermal fuses typically operate at a specified temperature. They sense the external temperature through an internal heat-sensitive fusible link made of heat-sensitive material. When the external temperature reaches the temperature at which the fusible link changes state, the fuse trips, breaking the series circuit and providing protection.

[0003] The hot melt block is the core technology in the production process of organic-based fusible links. Choosing different thermistor materials as raw materials for the hot melt block results in variations in the hot melt block's resistance to deliquescence and high-temperature resistance due to differences in the physical and chemical properties of the thermistor materials. This leads to differences in the thermal stability, physical or chemical stability of the fusible link containing the hot melt block, and it is also susceptible to environmental influences. When the temperature of the fusible link containing the hot melt block approaches or even reaches its melting point, the hot melt block will sublimate, resulting in a reduction in size. Furthermore, due to the deliquescence of the hot melt block, it will dissolve upon contact with water or in high-humidity environments. Both of these situations will cause damage to the hot melt block. In addition, due to the sublimation of organic matter, the hot melt block may shrink or soften and deform before reaching the designated operating temperature, leading to premature malfunction of the fusible link. Especially under energized conditions, sublimation of the hot melt block is accelerated in environments below the designated operating temperature. Therefore, the inherent stability of the hot melt block plays a crucial role in the stability of the fusible link. Summary of the Invention

[0004] The purpose of this invention is to provide a highly stable hot melt block with high insulation resistance, fast operation response rate, and superior resistance to deliquescence and high temperature stability.

[0005] Another objective of this invention is to provide a method for preparing a highly stable hot melt block, which is simple to operate and has low production costs, and is suitable for large-scale industrial production.

[0006] A third objective of this invention is to provide a thermal fuse with high insulation and stability.

[0007] The technical problem solved by this invention is achieved by the following technical solution.

[0008] This invention proposes a highly stable hot melt block, which, by weight percentage, comprises 90-100% N,N-diphthalimide ethane-3 organic compound, 0-10% filler, 0-1% lubricant, 0-2% binder, and 0-2% pigment.

[0009] This invention proposes a method for preparing a highly stable hot melt block, comprising the following steps:

[0010] S1. Weigh each component according to the stated weight percentage;

[0011] S2. The N,N-diphthalimide ethane-3 organic compound, the filler, the lubricant, the binder and the pigment are mixed, then granulated, pelletized and sieved to obtain a particulate mixture;

[0012] S3. The particulate mixture is pressed to obtain the highly stable hot melt block.

[0013] The present invention also proposes a thermally fused fuse, comprising the aforementioned highly stable thermally fused block.

[0014] The beneficial effects of the high-stability hot melt block, its preparation method, and the hot melt fracture body of the present invention are as follows:

[0015] 1. This invention uses N,N-diphthalimide ethane-3 organic compound as the main material, and prepares a highly stable hot melt block by adding appropriate amounts of fillers, lubricants, binders, and pigments. Compared with existing hot melt blocks prepared using the heat-sensitive material phthalimide, this highly stable hot melt block has high insulation resistance, fast operation response rate, and better resistance to deliquescence and high temperature stability, enabling the hot melt fuse to work stably at a predetermined temperature, thereby improving the stability and reliability of the hot melt fuse.

[0016] 2. The preparation method of the high-stability hot melt block of the present invention is simple, easy to operate, and has low production cost, thereby improving the economic value of enterprises and providing a broad theoretical basis for the production of hot melt blocks.

[0017] 3. The hot-melt fuse assembled using the high-stability hot-melt block of this invention, under the deformation caused by the softening or melting of the hot-melt block (i.e., at an operating temperature as high as 450°C), after a certain time (generally 10 minutes according to IEC60691 or GB9816.1), provides an insulation of at least 0.2 MΩ. When carrying the rated current, it can remain non-conductive for 168 hours, and its surface temperature (i.e., holding temperature Th) can reach 210°C, while the holding temperature of hot-melt blocks of the same specifications commonly used in the industry is basically around 200°C. The high-stability hot-melt block of this invention significantly improves the holding temperature, offering a significant advantage. Attached Figure Description

[0018] To more clearly illustrate the technical solutions of the embodiments of the present invention, the accompanying drawings used in the embodiments will be briefly introduced below. It should be understood that the following drawings only show some embodiments of the present invention and should not be regarded as a limitation on the scope. For those skilled in the art, other related drawings can be obtained based on these drawings without creative effort.

[0019] Figure 1 The IR spectrum of N,N-diphthalimide ethane-3 organic compound;

[0020] Figure 2 This is a flowchart illustrating the preparation process of the highly stable hot melt block of the present invention;

[0021] Figure 3 This is a cross-sectional view of the hot melt fracture body equipped with a high-stability hot melt block of the present invention before operation;

[0022] Figure 4 This is a cross-sectional view of the hot melt fracture body equipped with a high-stability hot melt block of the present invention after operation;

[0023] Figure 5 This is a schematic diagram of the structure of the high-stability hot melt block in Embodiment 1 of the present invention;

[0024] Figure 6 The graph shows the mass change of N,N-diphthalimide ethane-3 organic compound and phthalimide. Detailed Implementation

[0025] To make the objectives, technical solutions, and advantages of the embodiments of the present invention clearer, the technical solutions in the embodiments of the present invention will be clearly and completely described below. Where specific conditions are not specified in the embodiments, conventional conditions or conditions recommended by the manufacturer shall apply. Reagents or instruments whose manufacturers are not specified are all conventional products that can be purchased commercially.

[0026] The following provides a detailed description of the high-stability hot melt block, its preparation method, and the hot melt fracture body according to embodiments of the present invention.

[0027] The present invention provides a highly stable hot melt block, which, by weight percentage, comprises 90-100% N,N-diphthalimide ethane-3 organic compound, 0-10% filler, 0-1% lubricant, 0-2% binder and 0-2% pigment.

[0028] This invention addresses the issue of sublimation and deliquescence in currently used thermistor materials for the same temperature specifications. It proposes a new thermistor material, N,N-diphthalimide ethane-3, with a melting point of approximately 238°C. This material exhibits low sublimation characteristics and is insoluble in water. In practical applications, it effectively prevents malfunctions caused by particle shrinkage leading to separation of the star-shaped spring 5 from the electrode leads, especially under energized conditions below the specified operating temperature, where sublimation can cause the sensing particles to sublimate. Using N,N-diphthalimide ethane-3, with its low sublimation characteristics, effectively reduces this risk. Table 1 compares the basic characteristics of phthalimide (the old material) and N,N-diphthalimide ethane-3 (the new material), the main materials currently used in the industry for the same temperature specifications. Figure 1 The image shows the IR spectrum of N,N-diphthalimide ethane-3 organic compound.

[0029] Table 1 Comparison of basic physicochemical properties between new and old materials.

[0030]

[0031] Due to the water insolubility and relatively low sublimation properties of N,N-diphthalimide ethane-3 organic compounds, their fusible links as thermal fuses exhibit high stability and a longer service life. Even under high temperature and humidity conditions, the fuse remains stable for a considerable period, preventing damage to its insulation performance. Fuses made primarily from N,N-diphthalimide ethane-3 organic compounds also prevent degradation of their electrical and other similar properties during storage and use, and prevent changes due to prolonged exposure. This allows the fuse to operate stably at a predetermined temperature, thereby improving its stability and reliability.

[0032] Furthermore, in a preferred embodiment of the present invention, the purity of the N,N-diphthalimide ethane-3 organic compound is ≥98.0% (GC).

[0033] Furthermore, in a preferred embodiment of the present invention, the filler is selected from one or more of calcium carbonate, magnesium aluminum silicate, silica, mica powder, and quartz powder. The filler added in this invention facilitates the molding of the hot melt block and increases its strength after molding, thereby preventing defects such as cracks, peeling, or breakage due to insufficient hardness. In addition, adding filler allows the hot melt block to maintain its geometric dimensions at high temperatures and helps improve the insulation resistance after the hot melt fuse has activated.

[0034] Furthermore, in a preferred embodiment of the present invention, the lubricant is selected from one or a mixture of several of calcium stearate, talc, stearamide, and magnesium silicate. Using a lubricant facilitates demolding of the formed hot melt block, thereby effectively reducing defects such as gaps caused by sticking to the mold, and also helps to ensure the uniformity of the filler density.

[0035] Furthermore, in a preferred embodiment of the present invention, the adhesive is a powder adhesive, which is selected from one or more of epoxy powder, polyamide powder, and polyethylene glycol powder. The present invention uses an adhesive with a melting point or heat distortion temperature close to that of the organic powder, which can effectively suppress the sublimation of the hot melt in an environment below the specified operating temperature.

[0036] This invention uses N,N-diphthalimide ethane-3 organic compound as the main material, and prepares a highly stable hot melt block by adding appropriate amounts of fillers, lubricants, binders and pigments. This highly stable hot melt block is an organic type hot melt block, which has the characteristics of high insulation resistance, fast operation response rate, deliquescence resistance and stability.

[0037] Reference Figure 2 As shown, the present invention also provides a method for preparing a highly stable hot melt block, comprising the following steps:

[0038] S1. Weigh each group according to the stated weight percentage.

[0039] S2. The N,N-diphthalimide ethane-3 organic compound, the filler, the lubricant, the binder and the pigment are mixed, granulated, and sieved to obtain a particulate mixture.

[0040] S3. The particulate mixture is pressed to obtain the highly stable hot melt block. Preferably, the highly stable hot melt block has a diameter of 3.2 mm and a height of 3.0 mm.

[0041] Reference Figures 3-4 As shown, the present invention also provides a thermal fuse, comprising a first lead 1, a sealing resin 2, an insulator 3, a thin spring 4, a star-shaped spring 5, a circular piece 6, a thick spring 7, a high-stability thermal fuse block 8, a shell 9, and a second lead 10.

[0042] Specifically, through holes are provided at both ends of the outer casing 9. A first lead wire 1 is wrapped around one end of the outer casing 9, and a second lead wire 10 is wrapped around the other end, with the first lead wire 1 and the second lead wire 10 passing through their respective through holes. Sealing resin 2 is provided at the connection end between the outer casing 9 and the first lead wire 1. An insulator 3 is provided inside the outer casing 9, and a thin spring 4 is fitted onto it. A star-shaped spring 5 is located at the end of the insulator 3 where the thin spring is located, and the first lead wire 1 passes through the insulator 3 and connects to the star-shaped spring 5. A thick spring is provided at the end of the star-shaped spring 5 away from the insulator 3, and a high-stability heat-fused block 8 is provided at the end of the thick spring away from the star-shaped spring 5. The high-stability heat-fused block 8 is connected to the second lead wire 10. A circular piece 6 is also provided between the thick spring 7 and the star-shaped spring 5, and between the thick spring 7 and the high-stability heat-fused block 8.

[0043] The features and performance of the present invention will be further described in detail below with reference to embodiments.

[0044] Example 1

[0045] This embodiment provides a highly stable hot melt block, which, by weight percentage, comprises 100% N,N-diphthalimide ethane-3, and is prepared according to the following method:

[0046] (1) Weigh out N,N-diphthalimide-3 organic compound.

[0047] (2) The N,N-diphthalimide ethane-3 organic compound was granulated, granulated and sieved into a granular mixture and mixed evenly.

[0048] (3) The granular mixture obtained in step (2) is pressed into cylinders 8 with a diameter of 3.2 mm and a height of 3.0 mm using a pressing machine, which are the high-stability hot melt blocks. Figure 5 (As shown).

[0049] Example 2

[0050] This embodiment provides a highly stable hot melt block, comprising, by weight percentage, 95% N,N-diphthalimide ethane-3 organic compound, 3.0% quartz powder, 0.5% calcium stearate, 0.5% epoxy resin powder, and 1.0% green pigment, which is prepared according to the following method:

[0051] (1) Weigh out N,N-diphthalimide ethane-3 organic compound, quartz powder, calcium stearate, epoxy resin powder and green pigment.

[0052] (2) The above substances are granulated, granulated and sieved into a granular mixture and mixed evenly.

[0053] (3) The granular mixture obtained in step (2) is made into a cylinder 8 with a diameter of 3.2 mm and a height of 3.0 mm using a press, which is a high-stability hot melt block.

[0054] Example 3

[0055] This embodiment provides a highly stable hot melt block, comprising, by weight percentage, 90% N,N-diphthalimide ethane-3 organic compound, 7.0% calcium carbonate, 1.0% calcium stearate, 1.0% polyamide, and 1.0% blue pigment, prepared according to the following method:

[0056] (1) Weigh out N,N-diphthalimide-3 organic compound, calcium carbonate, calcium stearate, polyamide and blue pigment.

[0057] (2) The above substances are granulated, granulated and sieved into a granular mixture and mixed evenly.

[0058] (3) The granular mixture obtained in step (2) is made into a cylinder 8 with a diameter of 3.2 mm and a height of 3.0 mm using a press, which is a high-stability hot melt block.

[0059] Comparative Example 1

[0060] This comparative example provides a hot melt block comprising, by weight percentage, 95% phthalimide, 3.0% quartz powder, 0.5% calcium stearate, 0.5% epoxy resin powder, and 1.0% green pigment, prepared according to the following method:

[0061] (1) Weigh out phthalimide, quartz powder, calcium stearate, epoxy resin powder and green pigment.

[0062] (2) The above substances are granulated, granulated and sieved into a granular mixture and mixed evenly.

[0063] (3) The granular mixture obtained in step (2) is made into a cylinder 8 with a diameter of 3.2 mm and a height of 3.0 mm using a press, which is a high-stability hot melt block.

[0064] Experimental Example 1

[0065] The high-stability hot melt block from Example 1 was loaded into... Figure 1 The thermal fuse (AUPO BF) was tested, and then the operating temperature of the thermal fuse was tested using an oil bath. The test results are shown in Table 2.

[0066] Table 2 Operating Temperatures of Fusible Links

[0067]

[0068] As can be seen from Table 2, the actual operating temperature distribution of the hot-melt fuse with N,N-diphthalimide ethane-3 as the main material of the hot melt block is concentrated, which meets the requirements of the IEC60691 safety standard.

[0069] Experimental Example 2

[0070] The high-stability hot melt block of Example 2 and the hot melt block of Comparative Example 1 were respectively loaded into... Figure 2 The thermal fuse shown is an AUPO BF. The Th performance of the high-stability thermal fuse of Comparative Example 2 and the thermal fuse of Comparative Example 1 was compared according to the standards defined in IEC 60691 / UL 1020. Th is the highest temperature at which the conductivity state of the thermal fuse remains unchanged for one week when the rated current is applied. The test results are shown in Table 3.

[0071] Table 3 Th properties of hot melt blocks

[0072]

[0073] As can be seen from Table 2, the hot melt fuse with N,N-diphthalimide ethane-3 as the main material of the hot melt block has a higher Th temperature, which meets the requirements of IEC60691 safety standard.

[0074] Experimental Example 3

[0075] The high-stability hot melt block from Example 3 was loaded into... Figure 2 In the thermal fuse shown, the Tm performance of the high-stability thermal fuse of Example 3 was tested according to the standard defined by IEC60691 / UL1020. Tm is the highest temperature at which the thermal fuse can maintain its mechanical and electrical properties without impairment for a specified time after being changed to an open circuit state. The temperature of the constant temperature chamber was controlled at +0 / -5°C of the set temperature. The three samples were connected in parallel and placed in the oven, and maintained at this temperature for 10 minutes. Then, a withstand voltage test and an insulation resistance test were performed. After the test, the samples should not have flashover, breakdown or reconnection. The test results are shown in Table 4.

[0076] Table 4 Results of withstand voltage test and insulation resistance test

[0077]

[0078] Y: Reconnection; N: No reconnection; OK: No flashover or breakdown in the sample; NG: Flashover or breakdown in the sample;

[0079] As can be seen from Table 4, when the three samples were connected in parallel and tested under pressure, there were no reconnections, flashovers, or breakdowns, indicating that the thermal fuse with the new material as the heat-sensitive material meets the requirements of the IEC60691 safety standard.

[0080] Test Example 4

[0081] This experimental example studies the temperature resistance of heat-sensitive materials (N,N-diphthalimide ethane-3 organic compound and phthalimide) based on the mass loss rate caused by the sublimation of organic matter, including the following steps:

[0082] Equal masses of N,N-diphthalimide ethane-3 organic compound (new material) and phthalimide (old material) were placed in the same container and then placed in an oven at a constant temperature (200℃) for a certain period of time (168h). The temperature resistance of the heat-sensitive material was indirectly reflected by comparing the sublimation mass loss rate of the materials. The test results are as follows: Figure 6 As shown.

[0083] like Figure 6 The figure shows the mass change curves of N,N-diphthalimide ethane-3 organic compound and phthalimide. From... Figure 6 It can be seen that at 200℃, the sublimation mass loss rate of the new material is 0.19%, while that of the old material reaches 8.70%, indicating that the thermal stability of the new material is significantly better than that of the old material. The thermal stability of the fused block is very important for the fused fuse, as it prevents unexpected circuit breaking caused by volume reduction and mass loss due to relatively strong sublimation during use.

[0084] Experimental Example 5

[0085] This experimental example uses mass loss rate to study the deliquescence of hot melt, including the following methods:

[0086] A certain amount of high-stability hot melt block from Example 2 and a certain amount of hot melt block from Comparative Example 1 were taken and weighed. The high-stability hot melt block and the hot melt block were then immersed in water at 25°C for 24 hours. After centrifugation, the water was discarded, dried at room temperature, and weighed. The weight was compared with the value measured before immersion in water. The test results are shown in Table 5.

[0087] Table 5 Mass Loss of Hot Melt Block

[0088] Initial weight / g Weight after test / g Quality loss rate Example 2 5.09 5.09 0％ Comparative Example 1 5.07 5.02 0.99％

[0089] As shown in Table 5, the mass loss rate of the high-stability hot melt block in Example 2 was 0%, while the mass loss rate of the hot melt block in Comparative Example 1 was 0.99%. The mass loss rate of the hot melt block prepared using the new material was less than that of the hot melt block prepared using the old material. Therefore, the hot melt block prepared using the new material has better deliquescence resistance than the hot melt block prepared using the old material.

[0090] The embodiments described above are some, but not all, embodiments of the present invention. The detailed description of the embodiments of the present invention is not intended to limit the scope of the claimed invention, but merely to illustrate selected embodiments. All other embodiments obtained by those skilled in the art based on the embodiments of the present invention without inventive effort are within the scope of protection of the present invention.

Claims

1. A highly stable hot melt block, characterized in that, By weight percentage, it comprises 90–100% N,N-diphthalimide ethane-3 organic compounds, 0–10% fillers, 0–1% lubricants, 0–2% adhesives, and 0–2% pigments.

2. The high-stability hot melt block according to claim 1, characterized in that, The purity of the N,N-diphthalimide ethane-3 organic compound is ≥98.0% (GC).

3. The high-stability hot melt block according to claim 1, characterized in that, The filler is selected from one or more of calcium carbonate, magnesium aluminum silicate, silica, mica powder, and quartz powder.

4. The high-stability hot melt block according to claim 1, characterized in that, The lubricant is selected from one or a mixture of several of calcium stearate, talc, stearamide, and magnesium silicate.

5. The high-stability hot melt block according to claim 1, characterized in that, The adhesive is a powder adhesive, which is selected from one or more of epoxy powder, polyamide powder, and polyethylene glycol powder.

6. A method for preparing a highly stable hot melt block, characterized in that, Includes the following steps: S1. Weigh each component according to the weight percentage as described in any one of claims 1 to 5; S2. The N,N-diphthalimide ethane-3 organic compound, the filler, the lubricant, the binder and the pigment are mixed, then granulated, pelletized and sieved to obtain a particulate mixture; S3. The particulate mixture is pressed to obtain the highly stable hot melt block.

7. A thermal fuse, characterized in that, Including the highly stable hot melt block as described in any one of claims 1 to 5.

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