A waterproof and fireproof bimetallic thermostat packaging shell and its packaging process

Abstract

The invention relates to the technical field of composite materials, and in particular to a waterproof and fireproof bimetallic thermostat packaging shell and a packaging process thereof; the invention uses epoxy resin as the packaging shell of the bimetallic thermostat, thereby reducing the packaging process and the time cost, and in order to enhance the water resistance and fire resistance of the epoxy resin, the invention also performs a blending modification treatment on the epoxy resin to prepare a flame-retardant modified carbon nanotube, grafts a carboxyl group on the carbon nanotube, and utilizes the carboxyl group to react with an isocyanate group to generate a free isocyanate group, and then grafts the carboxyl group with a branched phosphorus silicon polymer of an amino group, thereby making the carbon nanotube have certain flame retardant properties, and the free amino group can also be utilized to introduce a silicon-oxygen bond into the epoxy resin, thereby reducing its surface energy and improving the hydrolysis resistance of the epoxy resin, thereby enhancing the adaptability of the packaging shell to various environments.

Description

Technical Field

[0001] The invention relates to the technical field of composite materials, in particular to a waterproof and fireproof bimetallic thermostat packaging shell and a packaging process thereof. Background Art

[0002] In the existing process, the traditional bimetallic thermostat packaging process mainly relies on pressing the shell and using epoxy resin to lock the air to achieve packaging. However, this type of packaging process often faces the problems of high cost, high defect rate and complicated process. The simple use of epoxy resin for packaging often faces the problem of insufficient flame retardancy of epoxy resin and decreased strength due to hydrolysis erosion. Summary of the invention

[0003] The object of the present invention is to provide a waterproof and fireproof bimetallic thermostat packaging shell and a packaging process thereof to solve the problems raised in the above background technology.

[0004] In order to solve the above technical problems, the present invention provides the following technical solutions: a waterproof and fireproof bimetallic thermostat packaging shell, characterized in that: the waterproof and fireproof bimetallic thermostat packaging shell comprises the following components by weight: 60-80 parts of bisphenol A epoxy resin, 27.5-38.5 parts of curing agent, 5-15 parts of flame retardant modified carbon nanotubes, and 15-20 parts of inorganic filler.

[0005] Furthermore, the epoxy resin is double A-type epoxy resin E-51; and the inorganic filler is antimony trioxide.

[0006] Furthermore, the curing agent is any one of phthalic anhydride and maleic anhydride.

[0007] Furthermore, the method for preparing the flame retardant modified carbon nanotubes comprises the following steps:

[0008] a. Disperse the carbon nanotubes in concentrated sulfuric acid, treat in an ice water bath, ultrasonically disperse for 10-20 minutes, add potassium permanganate, heat to 40-45°C, stir and react for 30-45 minutes, heat to 80-90°C, continue to react for 0.5-1h, filter and collect the filtered product after the reaction is completed, wash with deionized water until neutral, and obtain carboxylated carbon nanotubes;

[0009] b. Dissolve isophorone diisocyanate in DMF, stir evenly, add carboxylated carbon nanotubes, heat to 35-40°C, react with ultrasound for 1.5-3h, filter, and vacuum dry to constant weight to obtain isocyanate-terminated carbon nanotubes;

[0010] c. Disperse hexachlorocyclotriphosphazene in n-heptane, treat in an ice-water bath, stir evenly, and then dropwise add to a n-heptane solution containing 1,3-bis(3-aminopropyl)-1,1,3,3-tetramethyldisiloxane for 1-1.5 hours. After the addition is completed, heat to 45-60° C., continue to react for 0.5-1 hour, and then vacuum dry to constant weight to obtain a branched phosphosilicate polymer with an amino group terminal;

[0011] d. Mix the isocyanate-terminated carbon nanotubes prepared in step b and the amino-terminated branched phosphosilicate polymer prepared in step c, dissolve them in DMF, heat to 60-80° C., react for 4-8 hours, filter, collect the filtered product and vacuum dry it to constant weight to obtain flame-retardant modified carbon nanotubes.

[0012] Furthermore, in step a, the mass volume ratio of the carbon nanotubes, concentrated sulfuric acid and potassium permanganate is 1-5g:30ml:3.5-7g in parts by weight.

[0013] Furthermore, in step b, the mass ratio of isophorone diisocyanate to carboxylated carbon nanotubes is (0.5-3):1.

[0014] Furthermore, in step c, the molar ratio of hexachlorocyclotriphosphazene to 1,3-bis(3-aminopropyl)-1,1,3,3-tetramethyldisiloxane is 1:(4-8).

[0015] Furthermore, in step d, the mass ratio of the isocyanate-terminated carbon nanotubes to the amino-terminated branched phosphosilicate polymers is 1:(0.1-0.3) in parts by weight.

[0016] A packaging process for a waterproof and fireproof bimetallic thermostat packaging shell comprises the following steps:

[0017] S1. Immerse the inorganic filler in the silane coupling agent KH-550, immerse for 10-15 minutes, filter and separate the inorganic filler, blend it with bisphenol A epoxy resin, stir for 10-15 minutes, add flame retardant modified carbon nanotubes, continue to mix for 15-20 minutes, add curing agent, continue to mix for 10-15 minutes, and obtain epoxy resin encapsulation shell glue;

[0018] S2. Place the bimetallic thermostat in a precision packaging mold, add epoxy resin packaging shell glue for injection molding, heat to 80-90℃ and cure for 1.5-2h to complete the packaging.

[0019] In order to reduce the packaging process steps of the bimetallic thermostat, the present invention uses epoxy resin as the packaging shell. However, pure epoxy resin often has problems such as insufficient strength, low impact strength, flammability and easy hydrolysis due to its own properties. Therefore, the present application performs a blending modification process on the epoxy resin to address this problem.

[0020] The present application prepares flame-retardant modified carbon nanotubes. Carbon nanotubes are a type of material with a very high aspect ratio and a huge specific surface area, and have high strength and thermal conductivity. However, the dispersion of pure carbon nanotubes in epoxy resin is poor, so the present application performs a modification treatment on the carbon nanotubes.

[0021] First, the present invention performs an oxidation treatment on the carbon nanotubes. In the presence of concentrated sulfuric acid, the carbon nanotubes are mixed with potassium permanganate, which has strong oxidizing properties, to oxidize the surface of the carbon nanotubes to generate carboxyl groups. Then, the present invention further uses isocyanate to treat the carboxyl groups on the surface of the carbon nanotubes, thereby grafting isocyanate groups on the surface of the carbon nanotubes to further improve the reactivity of the carbon nanotubes.

[0022] On this basis, the present application also utilizes hexachlorocyclotriphosphazene to react with 1,3-bis(3-aminopropyl)-1,1,3,3-tetramethyldisiloxane, and strictly limits the order of addition and the reaction temperature, thereby generating a branched phosphosilicate polymer with an amino terminal group, and mixing it with carbon nanotubes, utilizing the reaction between isocyanate groups and amino groups, thereby introducing phosphosilicate elements on the surface of the carbon nanotubes, thereby giving it certain flame retardant properties; at the same time, the free amino groups that have not reacted with the isocyanate groups can also participate in the curing reaction of the epoxy resin, thereby introducing silicon-oxygen bonds into the epoxy resin system, reducing its surface energy, and improving hydrolysis resistance.

[0023] Compared with the prior art, the beneficial effects achieved by the present invention are as follows: the present invention uses epoxy resin as the packaging shell of the bimetallic thermostat, which reduces the packaging process and reduces the time cost. In order to enhance the water resistance and fire resistance of the epoxy resin, the present invention also performs a blending modification treatment on the epoxy resin to prepare flame-retardant modified carbon nanotubes, grafts carboxyl groups on the carbon nanotubes, and utilizes them to react with isocyanate groups to generate free isocyanate groups, which are then grafted with branched phosphosilicon polymers with terminal amino groups, thereby giving them certain flame retardant properties. In addition, the free amino groups can also be used to introduce silicon-oxygen bonds into the epoxy resin, reduce its surface energy, and improve the hydrolysis resistance of the epoxy resin, thereby enhancing the adaptability of the packaging shell to various environments. DETAILED DESCRIPTION

[0024] The technical solutions in the embodiments of the present invention are described clearly and completely below. Obviously, the described embodiments are only part of the embodiments of the present invention, not all of them. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without creative work are within the scope of protection of the present invention.

[0025] In the embodiment of the present application, the antimony trioxide was purchased from Changzhou Chenzhizhou New Materials Co., Ltd.; the E51 epoxy resin was Phoenix brand epoxy resin 618; the carbon nanotubes were CP6062EX type carbon nanotubes; the 1,3-bis(3-aminopropyl)-1,1,3,3-tetramethyldisiloxane was purchased from Wuhan Kanos Technology Co., Ltd.;

[0026] Example 1.

[0027] A packaging process for a waterproof and fireproof bimetallic thermostat packaging shell comprises the following steps:

[0028] S1. By weight, 15 parts of antimony trioxide were immersed in a silane coupling agent KH-550. After immersion for 10 minutes, the inorganic filler was separated by filtration, and it was blended with 60 parts of E-51 epoxy resin. After blending and stirring at a rate of 250 rpm for 10 minutes, 5 parts of flame-retardant modified carbon nanotubes were added, and mixing was continued for 15 minutes. Then, 27.5 parts of maleic anhydride curing agent were added, and mixing was continued for 10 minutes to obtain an epoxy resin encapsulation shell glue;

[0029] The method for preparing the flame retardant modified carbon nanotubes comprises the following steps:

[0030] a. Disperse 100g of carbon nanotubes in 3L of concentrated sulfuric acid, treat in an ice-water bath to a constant temperature, disperse ultrasonically at a frequency of 20KHz for 10min, add 350g of potassium permanganate, heat to 40°C, stir and react for 30min, heat to 80°C, continue to react for 0.5h, filter and collect the filtered product after the reaction is completed, wash with deionized water until neutral, and obtain carboxylated carbon nanotubes;

[0031] b. 50 g of isophorone diisocyanate was dissolved in DMF, stirred evenly, and then 100 g of carboxylated carbon nanotubes were added, the temperature was raised to 35 ° C, and the reaction was ultrasonically treated for 1.5 h, filtered, and dried in vacuum at 60 ° C to constant weight to obtain carbon nanotubes with terminal isocyanate groups;

[0032] c. Disperse 10 mol of hexachlorocyclotriphosphazene in n-heptane, treat in an ice-water bath, stir evenly, and then dropwise add to a n-heptane solution containing 40 mol of 1,3-bis(3-aminopropyl)-1,1,3,3-tetramethyldisiloxane. The dropwise addition time is 1 hour. After the dropwise addition is completed, the temperature is raised to 45° C., the reaction is continued for 0.5 hours, and then vacuum dried at 60° C. to constant weight to obtain a branched phosphosilicate polymer with an amino group terminal;

[0033] d. Mix 100 g of the isocyanate-terminated carbon nanotubes prepared in step b and 10 g of the amino-terminated branched phosphosilicate polymer prepared in step c, disperse them in DMF, heat to 60° C., react for 4 h, filter, collect the filtered product and vacuum dry it to constant weight to obtain flame-retardant modified carbon nanotubes;

[0034] S2. Place the bimetallic temperature controller in a precision packaging mold, add epoxy resin packaging shell glue for injection molding, heat to 80℃ and cure for 1.5h to complete the packaging.

[0035] Example 2.

[0036] Compared with Example 1, this example increases the amount of flame retardant modified carbon nanotubes added in step S1;

[0037] A packaging process for a waterproof and fireproof bimetallic thermostat packaging shell comprises the following steps:

[0038] S1. By weight, 15 parts of antimony trioxide were immersed in a silane coupling agent KH-550. After immersion for 10 minutes, the inorganic filler was separated by filtration, and it was blended with 60 parts of E-51 epoxy resin. After blending and stirring at a rate of 250 rpm for 10 minutes, 15 parts of flame-retardant modified carbon nanotubes were added, and mixing was continued for 15 minutes. Then, 27.5 parts of maleic anhydride curing agent were added, and mixing was continued for 10 minutes to obtain an epoxy resin encapsulation shell glue;

[0039] The method for preparing the flame retardant modified carbon nanotubes comprises the following steps:

[0040] a. Disperse 100g of carbon nanotubes in 3L of concentrated sulfuric acid, treat in an ice-water bath to a constant temperature, disperse ultrasonically at a frequency of 20KHz for 10min, add 350g of potassium permanganate, heat to 40°C, stir and react for 30min, heat to 80°C, continue to react for 0.5h, filter and collect the filtered product after the reaction is completed, wash with deionized water until neutral, and obtain carboxylated carbon nanotubes;

[0041] b. 50 g of isophorone diisocyanate was dissolved in DMF, stirred evenly, and then 100 g of carboxylated carbon nanotubes were added, the temperature was raised to 35 ° C, and the reaction was ultrasonically treated for 1.5 h, filtered, and dried in vacuum at 60 ° C to constant weight to obtain carbon nanotubes with terminal isocyanate groups;

[0042] c. Disperse 10 mol of hexachlorocyclotriphosphazene in n-heptane, treat in an ice-water bath, stir evenly, and then dropwise add to a n-heptane solution containing 40 mol of 1,3-bis(3-aminopropyl)-1,1,3,3-tetramethyldisiloxane. The dropwise addition time is 1 hour. After the dropwise addition is completed, the temperature is raised to 45° C., the reaction is continued for 0.5 hours, and then vacuum dried at 60° C. to constant weight to obtain a branched phosphosilicate polymer with an amino group terminal;

[0043] d. Mix 100 g of the isocyanate-terminated carbon nanotubes prepared in step b and 10 g of the amino-terminated branched phosphosilicate polymer prepared in step c, disperse them in DMF, heat to 60° C., react for 4 h, filter, collect the filtered product and vacuum dry it to constant weight to obtain flame-retardant modified carbon nanotubes;

[0044] S2. Place the bimetallic temperature controller in a precision packaging mold, add epoxy resin packaging shell glue for injection molding, heat to 80℃ and cure for 1.5h to complete the packaging.

[0045] Example 3.

[0046] Compared with Example 2, this example increases the amount of isophorone diisocyanate added in step b;

[0047] A packaging process for a waterproof and fireproof bimetallic thermostat packaging shell comprises the following steps:

[0048] S1. By weight, 15 parts of antimony trioxide were immersed in a silane coupling agent KH-550. After immersion for 10 minutes, the inorganic filler was separated by filtration, and it was blended with 60 parts of E-51 epoxy resin. After blending and stirring at a rate of 250 rpm for 10 minutes, 15 parts of flame-retardant modified carbon nanotubes were added, and mixing was continued for 15 minutes. Then, 27.5 parts of maleic anhydride curing agent were added, and mixing was continued for 10 minutes to obtain an epoxy resin encapsulation shell glue;

[0049] The method for preparing the flame retardant modified carbon nanotubes comprises the following steps:

[0050] a. Disperse 100g of carbon nanotubes in 3L of concentrated sulfuric acid, treat in an ice-water bath to a constant temperature, disperse ultrasonically at a frequency of 20KHz for 10min, add 350g of potassium permanganate, heat to 40°C, stir and react for 30min, heat to 80°C, continue to react for 0.5h, filter and collect the filtered product after the reaction is completed, wash with deionized water until neutral, and obtain carboxylated carbon nanotubes;

[0051] b. 300 g of isophorone diisocyanate was dissolved in DMF, stirred evenly, and 100 g of carboxylated carbon nanotubes were added, heated to 35 ° C, and ultrasonically treated for 1.5 h, filtered, and dried at 60 ° C in vacuum to constant weight to obtain carbon nanotubes with isocyanate groups at the end;

[0052] c. Disperse 10 mol of hexachlorocyclotriphosphazene in n-heptane, treat in an ice-water bath, stir evenly, and then dropwise add to a n-heptane solution containing 40 mol of 1,3-bis(3-aminopropyl)-1,1,3,3-tetramethyldisiloxane. The dropwise addition time is 1 hour. After the dropwise addition is completed, the temperature is raised to 45° C., the reaction is continued for 0.5 hours, and then vacuum dried at 60° C. to constant weight to obtain a branched phosphosilicate polymer with an amino group terminal;

[0053] d. Mix 100 g of the isocyanate-terminated carbon nanotubes prepared in step b and 10 g of the amino-terminated branched phosphosilicate polymer prepared in step c, disperse them in DMF, heat to 60° C., react for 4 h, filter, collect the filtered product and vacuum dry it to constant weight to obtain flame-retardant modified carbon nanotubes;

[0054] S2. Place the bimetallic temperature controller in a precision packaging mold, add epoxy resin packaging shell glue for injection molding, heat to 80℃ and cure for 1.5h to complete the packaging.

[0055] Example 4.

[0056] Compared with Example 2, this example increases the amount of 1,3-bis(3-aminopropyl)-1,1,3,3-tetramethyldisiloxane added in step c;

[0057] A packaging process for a waterproof and fireproof bimetallic thermostat packaging shell comprises the following steps:

[0058] S1. By weight, 15 parts of antimony trioxide were immersed in a silane coupling agent KH-550. After immersion for 10 minutes, the inorganic filler was separated by filtration, and it was blended with 60 parts of E-51 epoxy resin. After blending and stirring at a rate of 250 rpm for 10 minutes, 15 parts of flame-retardant modified carbon nanotubes were added, and mixing was continued for 15 minutes. Then, 27.5 parts of maleic anhydride curing agent were added, and mixing was continued for 10 minutes to obtain an epoxy resin encapsulation shell glue;

[0059] The method for preparing the flame retardant modified carbon nanotubes comprises the following steps:

[0060] a. Disperse 100g of carbon nanotubes in 3L of concentrated sulfuric acid, treat in an ice-water bath to a constant temperature, disperse ultrasonically at a frequency of 20KHz for 10min, add 350g of potassium permanganate, heat to 40°C, stir and react for 30min, heat to 80°C, continue to react for 0.5h, filter and collect the filtered product after the reaction is completed, wash with deionized water until neutral, and obtain carboxylated carbon nanotubes;

[0061] b. 50 g of isophorone diisocyanate was dissolved in DMF, stirred evenly, and then 100 g of carboxylated carbon nanotubes were added, the temperature was raised to 35 ° C, and the reaction was ultrasonically treated for 1.5 h, filtered, and dried in vacuum at 60 ° C to constant weight to obtain carbon nanotubes with terminal isocyanate groups;

[0062] c. Disperse 10 mol of hexachlorocyclotriphosphazene in n-heptane, treat in an ice-water bath, stir evenly, and then dropwise add to a n-heptane solution containing 80 mol of 1,3-bis(3-aminopropyl)-1,1,3,3-tetramethyldisiloxane. The dropwise addition time is 1 hour. After the dropwise addition is completed, the temperature is raised to 45° C., the reaction is continued for 0.5 hours, and then vacuum dried at 60° C. to constant weight to obtain a branched phosphosilicate polymer with an amino group terminal;

[0063] d. Mix 100 g of the isocyanate-terminated carbon nanotubes prepared in step b and 10 g of the amino-terminated branched phosphosilicate polymer prepared in step c, disperse them in DMF, heat to 60° C., react for 4 h, filter, collect the filtered product and vacuum dry it to constant weight to obtain flame-retardant modified carbon nanotubes;

[0064] S2. Place the bimetallic temperature controller in a precision packaging mold, add epoxy resin packaging shell glue for injection molding, heat to 80℃ and cure for 1.5h to complete the packaging.

[0065] Example 5.

[0066] Compared with Example 2, this example increases the amount of inorganic filler added in step S1;

[0067] A packaging process for a waterproof and fireproof bimetallic thermostat packaging shell comprises the following steps:

[0068] S1. By weight, 20 parts of antimony trioxide were immersed in a silane coupling agent KH-550. After immersion for 10 minutes, the inorganic filler was separated by filtration, and it was blended with 60 parts of E-51 epoxy resin. After blending and stirring at a rate of 250 rpm for 10 minutes, 15 parts of flame-retardant modified carbon nanotubes were added, and mixing was continued for 15 minutes. Then, 27.5 parts of maleic anhydride curing agent were added, and mixing was continued for 10 minutes to obtain an epoxy resin encapsulation shell glue;

[0069] The method for preparing the flame retardant modified carbon nanotubes comprises the following steps:

[0070] a. Disperse 100g of carbon nanotubes in 3L of concentrated sulfuric acid, treat in an ice-water bath to a constant temperature, disperse ultrasonically at a frequency of 20KHz for 10min, add 350g of potassium permanganate, heat to 40°C, stir and react for 30min, heat to 80°C, continue to react for 0.5h, filter and collect the filtered product after the reaction is completed, wash with deionized water until neutral, and obtain carboxylated carbon nanotubes;

[0071] b. 50 g of isophorone diisocyanate was dissolved in DMF, stirred evenly, and then 100 g of carboxylated carbon nanotubes were added, the temperature was raised to 35 ° C, and the reaction was ultrasonically treated for 1.5 h, filtered, and dried in vacuum at 60 ° C to constant weight to obtain carbon nanotubes with terminal isocyanate groups;

[0072] c. Disperse 10 mol of hexachlorocyclotriphosphazene in n-heptane, treat in an ice-water bath, stir evenly, and then dropwise add to a n-heptane solution containing 40 mol of 1,3-bis(3-aminopropyl)-1,1,3,3-tetramethyldisiloxane. The dropwise addition time is 1 hour. After the dropwise addition is completed, the temperature is raised to 45° C., the reaction is continued for 0.5 hours, and then vacuum dried at 60° C. to constant weight to obtain a branched phosphosilicate polymer with an amino group terminal;

[0073] d. Mix 100 g of the isocyanate-terminated carbon nanotubes prepared in step b and 10 g of the amino-terminated branched phosphosilicate polymer prepared in step c, disperse them in DMF, heat to 60° C., react for 4 h, filter, collect the filtered product and vacuum dry it to constant weight to obtain flame-retardant modified carbon nanotubes;

[0074] S2. Place the bimetallic temperature controller in a precision packaging mold, add epoxy resin packaging shell glue for injection molding, heat to 80℃ and cure for 1.5h to complete the packaging.

[0075] Example 6.

[0076] A packaging process for a waterproof and fireproof bimetallic thermostat packaging shell comprises the following steps:

[0077] S1. By weight, 20 parts of antimony trioxide were immersed in a silane coupling agent KH-550. After immersion for 10 minutes, the inorganic filler was separated by filtration, and it was blended with 80 parts of E-51 epoxy resin. After blending and stirring at a rate of 250 rpm for 10 minutes, 15 parts of flame-retardant modified carbon nanotubes were added, and mixing was continued for 15 minutes. Then, 38.5 parts of maleic anhydride curing agent were added, and mixing was continued for 10 minutes to obtain an epoxy resin encapsulation shell glue;

[0078] The method for preparing the flame retardant modified carbon nanotubes comprises the following steps:

[0079] a. Disperse 500g of carbon nanotubes in 3L of concentrated sulfuric acid, treat in an ice-water bath to a constant temperature, disperse ultrasonically at a frequency of 20KHz for 15min, add 700g of potassium permanganate, heat to 45°C, stir and react for 45min, heat to 90°C, continue to react for 1h, filter and collect the filtered product after the reaction is completed, wash with deionized water until neutral, and obtain carboxylated carbon nanotubes;

[0080] b. 300 g of isophorone diisocyanate was dissolved in DMF, stirred evenly, and then 100 g of carboxylated carbon nanotubes were added, heated to 40 ° C, and ultrasonically treated for 3 h, filtered, and dried under vacuum at 60 ° C to constant weight to obtain carbon nanotubes with isocyanate groups at the end;

[0081] c. Disperse 10 mol of hexachlorocyclotriphosphazene in n-heptane, treat in an ice-water bath, stir evenly, and then dropwise add to a n-heptane solution containing 80 mol of 1,3-bis(3-aminopropyl)-1,1,3,3-tetramethyldisiloxane. The dropwise addition time is 1 hour. After the dropwise addition is completed, the temperature is raised to 60° C., the reaction is continued for 1 hour, and then vacuum dried at 60° C. to constant weight to obtain a branched phosphosilicate polymer with an amino group terminal;

[0082] d. Mix 100 g of the isocyanate-terminated carbon nanotubes prepared in step b and 30 g of the amino-terminated branched phosphosilicate polymer prepared in step c, disperse them in DMF, heat to 80° C., react for 8 h, filter, collect the filtered product and vacuum dry it to constant weight to obtain flame-retardant modified carbon nanotubes;

[0083] S2. Place the bimetallic temperature controller in a precision packaging mold, add epoxy resin packaging shell glue for injection molding, heat to 90℃ and cure for 2h to complete the packaging.

[0084] Comparative Example 1.

[0085] Compared with Example 2, this comparative example did not prepare flame-retardant modified carbon nanotubes, but only replaced them with equal amounts of commercially available nanotubes;

[0086] A packaging process for a waterproof and fireproof bimetallic thermostat packaging shell comprises the following steps:

[0087] S1. By weight, 15 parts of antimony trioxide were immersed in a silane coupling agent KH-550. After immersion for 10 minutes, the inorganic filler was separated by filtration, and it was blended with 60 parts of E-51 epoxy resin. After blending and stirring at a rate of 250 rpm for 10 minutes, 15 parts of carbon nanotubes were added, and mixing was continued for 15 minutes. Then, 27.5 parts of maleic anhydride curing agent were added, and mixing was continued for 10 minutes to obtain an epoxy resin encapsulation shell glue;

[0088] S2. Place the bimetallic temperature controller in a precision packaging mold, add epoxy resin packaging shell glue for injection molding, heat to 80℃ and cure for 1.5h to complete the packaging.

[0089] Testing: According to ASTM-D638, the epoxy resin encapsulation shell glue prepared in Examples 1-6 and Comparative Example 1 was processed into specimens, and their tensile strength and elongation at break were tested at 50 mm / min; according to ASTM-D256, their notched impact strength was tested at 1 / 8", 23°C; according to UL94, their flame retardant properties were tested; the test results are shown in the following table:

[0090]

[0091] Finally, it should be noted that the above description is only a preferred embodiment of the present invention and is not intended to limit the present invention. Although the present invention has been described in detail with reference to the aforementioned embodiments, those skilled in the art can still modify the technical solutions described in the aforementioned embodiments or replace some of the technical features therein by equivalents. Any modification, equivalent replacement, improvement, etc. made within the spirit and principle of the present invention shall be included in the protection scope of the present invention.

Claims

1. A waterproof and fireproof bimetallic thermostat packaging shell, characterized in that: The waterproof and fireproof bimetallic thermostat packaging shell comprises the following components by weight: 60-80 parts of bisphenol A epoxy resin, 27.5-38.5 parts of curing agent, 5-15 parts of flame-retardant modified carbon nanotubes, and 15-20 parts of inorganic filler; The method for preparing the flame retardant modified carbon nanotubes comprises the following steps: a. Disperse the carbon nanotubes in concentrated sulfuric acid, treat in an ice water bath, ultrasonically disperse for 10-20 minutes, add potassium permanganate, heat to 40-45°C, stir and react for 30-45 minutes, heat to 80-90°C, continue to react for 0.5-1h, filter and collect the filtered product after the reaction is completed, wash with deionized water until neutral, and obtain carboxylated carbon nanotubes; b. Dissolve isophorone diisocyanate in DMF, stir evenly, add carboxylated carbon nanotubes, heat to 35-40°C, react with ultrasound for 1.5-3h, filter, and vacuum dry to constant weight to obtain isocyanate-terminated carbon nanotubes; c. Disperse hexachlorocyclotriphosphazene in n-heptane, treat in an ice-water bath, stir evenly, and then dropwise add to a n-heptane solution containing 1,3-bis(3-aminopropyl)-1,1,3,3-tetramethyldisiloxane for 1-1.5 hours. After the addition is completed, heat to 45-60° C., continue to react for 0.5-1 hour, and then vacuum dry to constant weight to obtain a branched phosphosilicate polymer with an amino group terminal; d. Mix the isocyanate-terminated carbon nanotubes prepared in step b and the amino-terminated branched phosphosilicate polymer prepared in step c, dissolve them in DMF, heat to 60-80° C., react for 4-8 hours, filter, collect the filtered product and vacuum dry it to constant weight to obtain flame-retardant modified carbon nanotubes.

2. The waterproof and fireproof bimetallic thermostat packaging shell according to claim 1, characterized in that: The epoxy resin is double A-type epoxy resin E-51; the inorganic filler is antimony trioxide.

3. The waterproof and fireproof bimetallic thermostat packaging shell according to claim 1, characterized in that: The curing agent is any one of phthalic anhydride and maleic anhydride.

4. The waterproof and fireproof bimetallic thermostat packaging shell according to claim 1, characterized in that: In step a, the mass volume ratio of the carbon nanotubes, concentrated sulfuric acid and potassium permanganate is 1-5g:30ml:3.5-7g in parts by weight.

5. The waterproof and fireproof bimetallic thermostat packaging shell according to claim 1, characterized in that: In step b, the mass ratio of isophorone diisocyanate to carboxylated carbon nanotubes is (0.5-3):

1.

6. The waterproof and fireproof bimetallic thermostat packaging shell according to claim 1, characterized in that: In step c, the molar ratio of hexachlorocyclotriphosphazene to 1,3-bis(3-aminopropyl)-1,1,3,3-tetramethyldisiloxane is 1:(4-8).

7. The waterproof and fireproof bimetallic thermostat packaging shell according to claim 1, characterized in that: In terms of parts by weight, in step d, the mass ratio of the carbon nanotubes terminated with isocyanate groups to the branched phosphosilicate polymers terminated with amino groups is 1:(0.1-0.3).

8. A packaging process for a waterproof and fireproof bimetallic thermostat packaging shell according to any one of claims 1 to 7, characterized in that: The following steps are involved: S1. Immerse the inorganic filler in the silane coupling agent KH-550, immerse for 10-15 minutes, filter and separate the inorganic filler, blend it with bisphenol A epoxy resin, stir for 10-15 minutes, add flame retardant modified carbon nanotubes, continue to mix for 15-20 minutes, add curing agent, continue to mix for 10-15 minutes, and obtain epoxy resin encapsulation shell glue; S2. Place the bimetallic thermostat in a precision packaging mold, add epoxy resin packaging shell glue for injection molding, heat to 80-90℃ and cure for 1.5-2h to complete the packaging.

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