An automatic gluing process for a thermal protector

Abstract

The present invention relates to the technical field of coatings, and specifically to an automatic adhesive pasting process for a thermal protector. The present invention discloses an automatic adhesive pasting process for a thermal protector, which prepares an amino-terminated hyperbranched polysiloxane using the silane coupling agent 3-aminopropyltriethoxysilane, grafts and modifies the amino-terminated hyperbranched polysiloxane with salicylic acid, and blends it with epoxy resin to obtain an adhesive. The hyperbranched polysiloxane has silicon-oxygen bonds that are resistant to high temperatures, which can improve the high-temperature resistance of the adhesive. At the same time, the hyperbranched structure material has better film-forming properties, which can improve the adhesion ability of the adhesive. Salicylic acid not only has good antibacterial and anti-ultraviolet aging abilities, but also can improve the promoting effect of imidazole on the curing agent dicyandiamide. Therefore, the shear strength and peel strength of the adhesive are higher. After grafting salicylic acid onto the hyperbranched polysiloxane, it is beneficial to disperse more evenly, thus better playing its role.

Description

Technical Field

[0001] The present invention relates to the technical field of coatings, and specifically to an automatic gluing process for a thermal protector. Background Art

[0002] In actual production and life, overheating of circuits is a common problem. The reasons for overheating include excessive current, too long power-on time, incorrect circuit connection, etc. A thermal protector is a temperature controller composed of two different alloys combined together. When the temperature rises to the set temperature, the contacts automatically disconnect and stop working; while when the temperature is lower than the set temperature, the contacts automatically close and resume normal operation. By connecting the thermal protector to the circuit, it can not only effectively avoid the fire risk caused by high circuit temperature, but also prevent electronic devices from being damaged by heat.

[0003] During the production and processing of thermal protectors, gluing operations need to be carried out on one side of the edge. Conventional glues are not resistant to high temperatures, and their bonding performance will decline at high temperatures, affecting the gluing process. Therefore, there is a great need to invent an automatic gluing process for thermal protectors. Summary of the Invention

[0004] The purpose of the present invention is to provide an automatic gluing process for a thermal protector to solve the problems raised in the above background art.

[0005] To solve the above technical problems, the present invention provides the following technical solutions: An automatic gluing process for a thermal protector includes the following steps:

[0006] Step 1: Take a certain amount of 3-aminopropyltriethoxysilane, add deionized water, stir evenly to obtain a mixed solution A. Add a hydrochloric acid solution to the mixed solution A to adjust the pH value of the system, raise the temperature for reaction in a water bath, evaporate the solvent to dryness, and vacuum dry to obtain a viscous liquid, which is amino-terminated hyperbranched polysiloxane;

[0007] Step 2: Add N,N'-dicyclohexylcarbodiimide and 1-hydroxybenzotriazole to dichloromethane, stir until completely dissolved, add salicylic acid, stir for 2 h under an ice-water bath condition, and then dropwise add amino-terminated hyperbranched polysiloxane and stir to obtain a mixed solution B; Raise the temperature of the mixed solution B for reaction, and rotary evaporate to remove the solvent to obtain salicylic acid graft-modified amino-terminated hyperbranched polysiloxane;

[0008] Step 3: Mix and stir evenly E51 epoxy resin, salicylic acid graft-modified amino-terminated hyperbranched polysiloxane, dicyandiamide, imidazole, alumina powder, boron nitride powder, defoaming agent, and dispersant to obtain an adhesive;

[0009] Step 4: Coat the adhesive on a polyvinyl chloride film, cut and process to obtain a glue for a thermal protector, and attach it to the thermal protector through an automatic gluer.

[0010] Further, in step 1, in the mixed solution A, the content of each component, by weight, is 30-40 parts of 3-aminopropyltriethoxysilane and 60-80 parts of deionized water.

[0011] Further, in step 1, the pH value is adjusted to 4-5 with hydrochloric acid.

[0012] Further, in step 1, the water bath is heated to 50-60 °C, and the reaction time is 4-6 h.

[0013] Further, in step 2, in the mixed solution B, the content of each component, by weight, is 100-120 parts of N,N-dicyclohexylcarbodiimide, 70-130 parts of 1-hydroxybenzotriazole, 280-300 parts of dichloromethane, 50-70 parts of salicylic acid, and 20-30 parts of amino-terminated hyperbranched polysiloxane.

[0014] Further, in step 2, the mixed solution B is heated to 20-30 °C, and the reaction time is 6-8 h.

[0015] Further, in step 3, in the adhesive, the content of each component, by weight, is 100 parts of E51 epoxy resin, 1.5-2.5 parts of salicylic acid grafted modified amino-terminated hyperbranched polysiloxane, 8-12 parts of dicyandiamide, 5-8 parts of imidazole, 20-30 parts of alumina powder, 50-56 parts of boron nitride powder, and 10-14 parts of defoaming agent.

[0016] Compared with the prior art, the beneficial effects achieved by the present invention are as follows: The present invention uses salicylic acid grafted modified amino-terminated hyperbranched polysiloxane. There are high-temperature resistant silicon-oxygen bonds in the hyperbranched polysiloxane. After being blended with epoxy resin, it can improve the overall high-temperature resistance of the adhesive. At the same time, the hyperbranched structure material has good film-forming properties, so the adhesion ability of the adhesive is improved. In addition, salicylic acid not only has good antibacterial and anti-ultraviolet aging abilities, but also has a promoting effect on imidazole, which can improve the promoting effect of imidazole on the curing agent dicyandiamide, making the curing effect of epoxy resin better, and the shear strength and peel strength higher. After grafting salicylic acid onto the hyperbranched polysiloxane, it is beneficial to its more uniform dispersion in epoxy resin, so as to better play its role. Specific Embodiments

[0017] The technical solutions in the embodiments of the present invention will be clearly and completely described below. Obviously, the described embodiments are only a part of the embodiments of the present invention, rather than all of the embodiments. All other embodiments obtained by those of ordinary skill in the art based on the embodiments of the present invention without creative efforts shall fall within the protection scope of the present invention.

[0018] The raw materials used in the present invention and their sources are as follows: 3-aminopropyltriethoxysilane (CAS No.: 919-30-2), hydrochloric acid (CAS No.: 7647-01-0), N,N-dicyclohexylcarbodiimide (CAS No.: 538-75-0), 1-hydroxybenzotriazole (CAS No.: 2592-95-2), dichloromethane (CAS No.: 75-09-2) were all purchased from Aladdin; salicylic acid (CAS No.: 69-72-7) was purchased from Macklin; dicyandiamide (CAS No.: 461-58-5) was purchased from Pengsheng Chemical Industry; E51 epoxy resin was purchased from Baling Petrochemical, product number: CYD-128; imidazole (CAS No.: 288-32-4) was purchased from Longgu Biology; alumina powder was purchased from Zhengzhou Xinli Wear-resistant Materials; boron nitride powder was purchased from Liaoning Pengda Technology; defoaming agent HY-7010 was purchased from Jiading Chemistry.

[0019] Example 1:

[0020] Step 1: Take 30 g of 3-aminopropyltriethoxysilane, add 60 g of deionized water, stir evenly to obtain a mixed solution A. Add hydrochloric acid solution to the mixed solution A to adjust the pH value to 4, raise the temperature to 50 °C in a water bath, and react for 4 h. Then evaporate the solvent to dryness and vacuum dry to obtain a viscous liquid, which is amino-terminated hyperbranched polysiloxane; E51 epoxy resin;

[0021] Step 2: Add 100 g of N,N-dicyclohexylcarbodiimide and 70 g of 1-hydroxybenzotriazole to 280 g of dichloromethane, stir until completely dissolved, add 50 g of salicylic acid, and stir for 2 h under ice-water bath conditions; then dropwise add 20 g of amino-terminated hyperbranched polysiloxane to obtain a mixed solution B; raise the temperature of the mixed solution B to 20 °C and react for 6 h, and rotary evaporate to remove the solvent to obtain salicylic acid graft-modified amino-terminated hyperbranched polysiloxane;

[0022] Step 3: Mix 100 g of E51 epoxy resin, 1.5 g of salicylic acid graft-modified amino-terminated hyperbranched polysiloxane, 8 g of dicyandiamide, 5 g of imidazole, 20 g of alumina powder, 50 g of boron nitride powder, and 10 g of defoaming agent HY-7010 and stir evenly to obtain an adhesive;

[0023] Step 4: Coat the adhesive on a polyvinyl chloride film, cut and process to obtain a pressure-sensitive adhesive for a thermal protector, and attach it to the thermal protector through an automatic pressure-sensitive adhesive machine.

[0024] Example 2:

[0025] Step 1: Take 31 g of 3-aminopropyltriethoxysilane, add 63 g of deionized water, stir evenly to obtain a mixed solution A. Add hydrochloric acid solution to the mixed solution A to adjust the pH value to 4.5, heat it in a water bath to 55 °C, and after reacting for 4.5 h, evaporate the solvent to dryness and dry it under vacuum to obtain a viscous liquid, which is amino-terminated hyperbranched polysiloxane;

[0026] Step 2: Add 103 g of N,N'-dicyclohexylcarbodiimide and 77 g of 1-hydroxybenzotriazole to 282 g of dichloromethane, stir until completely dissolved, add 55 g of salicylic acid, and stir for 2 h under an ice-water bath; then dropwise add 24 g of amino-terminated hyperbranched polysiloxane to obtain a mixed solution B; heat the mixed solution B to 25 °C, react for 6.5 h, rotary evaporate to remove the solvent, and obtain salicylic acid graft-modified amino-terminated hyperbranched polysiloxane;

[0027] Step 3: Mix 100 g of E51 epoxy resin, 1.7 g of salicylic acid graft-modified amino-terminated hyperbranched polysiloxane, 8.5 g of dicyandiamide, 5.5 g of imidazole, 21 g of alumina powder, 51 g of boron nitride powder, and 10.7 g of defoamer HY-7010 and stir evenly to obtain an adhesive;

[0028] Step 4: Coat the adhesive on a polyvinyl chloride film, cut and process it to obtain a sticker for a thermal protector, and attach it to the thermal protector through an automatic sticker applicator.

[0029] Example 3:

[0030] Step 1: Take 34 g of 3-aminopropyltriethoxysilane, add 69 g of deionized water, stir evenly to obtain a mixed solution A. Add hydrochloric acid solution to the mixed solution A to adjust the pH value to 5, heat it in a water bath to 60 °C, and after reacting for 5 h, evaporate the solvent to dryness and dry it under vacuum to obtain a viscous liquid, which is amino-terminated hyperbranched polysiloxane;

[0031] Step 2: Add 109 g of N,N'-dicyclohexylcarbodiimide and 87 g of 1-hydroxybenzotriazole to 286 g of dichloromethane, stir until completely dissolved, add 57 g of salicylic acid, and stir for 2 h under an ice-water bath; then dropwise add 24 g of amino-terminated hyperbranched polysiloxane to obtain a mixed solution B; heat the mixed solution B to 30 °C, react for 7 h, rotary evaporate to remove the solvent, and obtain salicylic acid graft-modified amino-terminated hyperbranched polysiloxane;

[0032] Step 3: Mix 100 g of E51 epoxy resin, 1.8 g of salicylic acid graft-modified amino-terminated hyperbranched polysiloxane, 9.3 g of dicyandiamide, 6 g of imidazole, 22 g of alumina powder, 52 g of boron nitride powder, and 12 g of defoamer HY-7010 and stir evenly to obtain an adhesive;

[0033] Step 4: Coat the adhesive on the polyvinyl chloride film, cut and process it to obtain the adhesive tape for the thermal protector, and attach it to the thermal protector through an automatic taping machine.

[0034] Example 4:

[0035] Step 1: Take 35 g of 3-aminopropyltriethoxysilane, add 72 g of deionized water, stir evenly to obtain a mixed solution A. Add hydrochloric acid solution to the mixed solution A to adjust the pH value to 4, heat it in a water bath to 50 °C, and react for 5.5 h. Then evaporate the solvent to dryness and vacuum dry it to obtain a viscous liquid, which is amino-terminated hyperbranched polysiloxane.

[0036] Step 2: Add 110 g of N,N-dicyclohexylcarbodiimide and 93 g of 1-hydroxybenzotriazole to 292 g of dichloromethane, stir until completely dissolved, add 61 g of salicylic acid, and stir for 2 h under ice-water bath conditions; then dropwise add 25.8 g of amino-terminated hyperbranched polysiloxane to obtain a mixed solution B; heat the mixed solution B to 20 °C and react for 7.5 h, rotary evaporate to remove the solvent to obtain salicylic acid grafted and modified amino-terminated hyperbranched polysiloxane.

[0037] Step 3: Mix 100 g of E51 epoxy resin, 1.8 g of salicylic acid grafted and modified amino-terminated hyperbranched polysiloxane, 9 g of dicyandiamide, 7 g of imidazole, 23 g of alumina powder, 54 g of boron nitride powder, and 11 g of defoamer HY-7010 evenly to obtain the adhesive.

[0038] Step 4: Coat the adhesive on the polyvinyl chloride film, cut and process it to obtain the adhesive tape for the thermal protector, and attach it to the thermal protector through an automatic taping machine.

[0039] Example 5:

[0040] Step 1: Take 36 g of 3-aminopropyltriethoxysilane, add 73 g of deionized water, stir evenly to obtain a mixed solution A. Add hydrochloric acid solution to the mixed solution A to adjust the pH value to 5, heat it in a water bath to 50 °C, and react for 5 h. Then evaporate the solvent to dryness and vacuum dry it to obtain a viscous liquid, which is amino-terminated hyperbranched polysiloxane.

[0041] Step 2: Add 115 g of N,N-dicyclohexylcarbodiimide and 107 g of 1-hydroxybenzotriazole to 285 g of dichloromethane, stir until completely dissolved, add 63 g of salicylic acid, and stir for 2 h under ice-water bath conditions; then dropwise add 26 g of amino-terminated hyperbranched polysiloxane to obtain a mixed solution B; heat the mixed solution B to 25 °C and react for 6 h, rotary evaporate to remove the solvent to obtain salicylic acid grafted and modified amino-terminated hyperbranched polysiloxane.

[0042] Step 3: Mix 100 g of E51 epoxy resin, 1.9 g of salicylic acid grafted modified amino-terminated hyperbranched polysiloxane, 10 g of dicyandiamide, 7 g of imidazole, 26 g of alumina powder, 54.5 g of boron nitride powder, and 12 g of defoamer HY-7010 evenly to obtain an adhesive;

[0043] Step 4: Coat the adhesive onto a polyvinyl chloride film, cut and process it to obtain an adhesive tape for a thermal protector, and attach it to the thermal protector through an automatic taping machine.

[0044] Example 6:

[0045] Step 1: Take 37 g of 3-aminopropyltriethoxysilane, add 74 g of deionized water, stir evenly to obtain a mixed solution A. Add hydrochloric acid solution to the mixed solution A to adjust the pH value to 5, heat it in a water bath to 50 °C, react for 5 h, then evaporate the solvent to dryness and dry it under vacuum to obtain a viscous liquid, which is amino-terminated hyperbranched polysiloxane;

[0046] Step 2: Add 115 g of N,N'-dicyclohexylcarbodiimide and 120 g of 1-hydroxybenzotriazole to 300 g of dichloromethane, stir until completely dissolved, add 62 g of salicylic acid, and stir for 2 h under an ice-water bath condition; then dropwise add 27 g of amino-terminated hyperbranched polysiloxane to obtain a mixed solution B; heat the mixed solution B to 30 °C, react for 6 h, and remove the solvent by rotary evaporation to obtain salicylic acid grafted modified amino-terminated hyperbranched polysiloxane;

[0047] Step 3: Mix 100 g of E51 epoxy resin, 2.2 g of salicylic acid grafted modified amino-terminated hyperbranched polysiloxane, 10.5 g of dicyandiamide, 7.4 g of imidazole, 28 g of alumina powder, 55 g of boron nitride powder, and 13 g of defoamer HY-7010 evenly to obtain an adhesive;

[0048] Step 4: Coat the adhesive onto a polyvinyl chloride film, cut and process it to obtain an adhesive tape for a thermal protector, and attach it to the thermal protector through an automatic taping machine.

[0049] Example 7:

[0050] Step 1: Take 38 g of 3-aminopropyltriethoxysilane, add 76 g of deionized water, stir evenly to obtain a mixed solution A. Add hydrochloric acid solution to the mixed solution A to adjust the pH value to 4, heat it in a water bath to 50 °C, react for 4.5 h, then evaporate the solvent to dryness and dry it under vacuum to obtain a viscous liquid, which is amino-terminated hyperbranched polysiloxane;

[0051] Step 2: Add 117 g of N,N-dicyclohexylcarbodiimide and 126 g of 1-hydroxybenzotriazole to 296 g of dichloromethane, stir until completely dissolved, add 65 g of salicylic acid, and stir for 2 h under an ice-water bath; then dropwise add 28 g of amino-terminated hyperbranched polysiloxane to obtain a mixed solution B; warm the mixed solution B to 25 °C and react for 7.5 h, then rotary evaporate to remove the solvent to obtain salicylic acid-grafted modified amino-terminated hyperbranched polysiloxane;

[0052] Step 3: Mix and stir evenly 100 g of E51 epoxy resin, 1.5 - 2.5 g of salicylic acid-grafted modified amino-terminated hyperbranched polysiloxane, 10 g of dicyandiamide, 7.3 g of imidazole, 29 g of alumina powder, 53 g of boron nitride powder, and 12 g of defoamer HY-7010 to obtain an adhesive;

[0053] Step 4: Coat the adhesive onto a polyvinyl chloride film, cut and process it to obtain a sticker for a thermal protector, and attach it to the thermal protector through an automatic sticker applicator.

[0054] Example 8:

[0055] Step 1: Take 40 g of 3-aminopropyltriethoxysilane, add 80 g of deionized water, stir evenly to obtain a mixed solution A, add a hydrochloric acid solution to the mixed solution A to adjust the pH value to 5, warm it to 60 °C in a water bath, react for 6 h, then evaporate the solvent to dryness and dry it under vacuum to obtain a viscous liquid, which is amino-terminated hyperbranched polysiloxane;

[0056] Step 2: Add 117 g of N,N-dicyclohexylcarbodiimide and 126 g of 1-hydroxybenzotriazole to 296 g of dichloromethane, stir until completely dissolved, add 65 g of salicylic acid, and stir for 2 h under an ice-water bath; then dropwise add 28 g of amino-terminated hyperbranched polysiloxane to obtain a mixed solution B; warm the mixed solution B to 25 °C and react for 7.5 h, then rotary evaporate to remove the solvent to obtain salicylic acid-grafted modified amino-terminated hyperbranched polysiloxane;

[0057] Step 3: Mix and stir evenly 100 g of E51 epoxy resin, 2.5 g of salicylic acid-grafted modified amino-terminated hyperbranched polysiloxane, 12 g of dicyandiamide, 8 g of imidazole, 30 g of alumina powder, 56 g of boron nitride powder, and 14 g of defoamer HY-7010 to obtain an adhesive;

[0058] Step 4: Coat the adhesive onto a polyvinyl chloride film, cut and process it to obtain a sticker for a thermal protector, and attach it to the thermal protector through an automatic sticker applicator.

[0059] Comparative Example 1:

[0060] Do not add salicylic acid-grafted modified amino-terminated hyperbranched polysiloxane.

[0061] 100 g of E51 epoxy resin, 1.5 g of salicylic acid grafted modified amino-terminated hyperbranched polysiloxane, 8 g of dicyandiamide, 5 g of imidazole, 20 g of alumina powder, 50 g of boron nitride powder, and 10 g of defoamer HY-7010 were mixed and stirred evenly to obtain an adhesive; the adhesive was coated on a polyvinyl chloride film, cut and processed to obtain a sticker for a thermal protector, and pasted on the thermal protector through an automatic sticker machine.

[0062] Comparative Example 2:

[0063] The amino-terminated hyperbranched polysiloxane was not grafted and modified with salicylic acid.

[0064] Step 1: Take 31 g of 3-aminopropyltriethoxysilane, add 63 g of deionized water, stir evenly to obtain a mixed solution A, add a hydrochloric acid solution to the mixed solution A to adjust the pH value to 4.5, raise the temperature of the water bath to 55 °C, and react for 4.5 h. After that, the solvent was evaporated to dryness and vacuum dried to obtain a viscous liquid, which is amino-terminated hyperbranched polysiloxane;

[0065] Step 2: 100 g of E51 epoxy resin, 1.7 g of salicylic acid grafted modified amino-terminated hyperbranched polysiloxane, 8.5 g of dicyandiamide, 5.5 g of imidazole, 21 g of alumina powder, 51 g of boron nitride powder, and 10.7 g of defoamer HY-7010 were mixed and stirred evenly to obtain an adhesive;

[0066] Step 3: The adhesive was coated on a polyvinyl chloride film, cut and processed to obtain a sticker for a thermal protector, and pasted on the thermal protector through an automatic sticker machine.

[0067] Comparative Example 3:

[0068] Salicylic acid was directly blended with amino-terminated hyperbranched polysiloxane.

[0069] Step 1: Take 34 g of 3-aminopropyltriethoxysilane, add 69 g of deionized water, stir evenly to obtain a mixed solution A, add a hydrochloric acid solution to the mixed solution A to adjust the pH value to 5, raise the temperature of the water bath to 60 °C, and react for 5 h. After that, the solvent was evaporated to dryness and vacuum dried to obtain a viscous liquid, which is amino-terminated hyperbranched polysiloxane;

[0070] Step 2: 57 g of salicylic acid was stirred in an ice-water bath for 2 h; then 24 g of amino-terminated hyperbranched polysiloxane was added dropwise to obtain a mixed solution B; the mixed solution B was heated to 30 °C and reacted for 7 h, and the solvent was removed by rotary evaporation to obtain salicylic acid grafted modified amino-terminated hyperbranched polysiloxane;

[0071] Step 3: Mix 100 g of E51 epoxy resin, 1.8 g of salicylic acid grafted modified amino-terminated hyperbranched polysiloxane, 9.3 g of dicyandiamide, 6 g of imidazole, 22 g of alumina powder, 52 g of boron nitride powder, and 12 g of defoamer HY-7010 evenly to obtain an adhesive;

[0072] Step 4: Coat the adhesive on a polyvinyl chloride film, cut and process it to obtain a sticker for a thermal protector, and attach it to the thermal protector through an automatic sticker applicator.

[0073] Experiment: Perform performance tests on Examples 1-8 and Comparative Examples 1-3, where:

[0074] Peel strength: Test according to the method provided in GJB 446-1988; under the conditions of a temperature of 25 °C and an air humidity of 45%, use a tensile testing machine (Dongguan Lixian Instrument Technology Co., Ltd., HZ-1007E) for testing, and the loading speed of the testing machine is 100 mm / min;

[0075] Shear strength: Test according to the method provided in GB / T 7124-2008; symmetrically clamp the sample on the fixture, the distance from the clamping position to the nearest bonding end is 50 mm, use a tensile testing machine (Dongguan Lixian Instrument Technology Co., Ltd., HZ-1007E) to conduct the experiment at a speed of 50 mm / min, the failure time is 65 s, and record the maximum load of the cutting review;

[0076] Antibacterial performance: Coat the adhesive on the surface of a polyvinyl chloride film with a diameter of 6 cm, place it in a Candida albicans culture dish, test the number of colonies after 48 h, and calculate the antibacterial rate;

[0077] Thermogravimetric analysis: Test on a Swiss Mettler TGA SDTA 851 Analyzer instrument, the temperature range is 30-500 °C, the heating rate is 10 °C / min, the test environment atmosphere is nitrogen and air, and record the temperature T when the thermal weight loss is 5%; 5％ ;

[0078] The experimental results are shown in the following table:

[0079] Example <![CDATA[Peeling strength / kN m -1 > Shear strength / MPa Antibacterial property / % <![CDATA[Thermogravimetric temperature T 5％ / ℃]]> Example 1 0.97 27.7 98.4 416 Example 2 0.94 28.3 97.7 418 Example 3 0.95 27.9 98.2 412 Example 4 1.02 27.6 96.7 417 Example 5 0.98 28.4 96.5 410 Example 6 0.91 27.5 97.1 414 Example 7 0.95 27.3 98.2 419 Example 8 0.93 28.0 97.9 415 Comparative Example 1 0.63 23.8 90.7 368 Comparative Example 2 0.74 24.6 91.3 405 Comparative Example 3 0.81 26.8 95.6 403

[0080] Conclusion: The data of Examples 1-8 show that the adhesives prepared by blending salicylic acid graft-modified amino-terminated hyperbranched polysiloxane with epoxy resin have good properties. Taking Example 1 as a reference, the data of Comparative Example 1 show that in the case of adding salicylic acid graft-modified amino-terminated hyperbranched polysiloxane, the adhesives have higher antibacterial properties, shear strength and peel strength, and at the same time, the thermal stability is also improved. This is mainly because the hyperbranched structure materials have better film-forming properties, so the adhesion ability of the adhesives is improved. Taking Example 2 as a reference, the data of Comparative Example 2 show that adding amino-terminated hyperbranched polysiloxane can improve the heat resistance of the adhesives. In addition, since the curing accelerator used in the present invention is imidazole, and the addition of salicylic acid can improve the promoting effect of imidazole on the curing agent dicyandiamide, the shear strength and peel strength of the adhesives are higher. Taking Example 3 as a reference, the data of Comparative Example 3 show that compared with salicylic acid graft-modified amino-terminated hyperbranched polysiloxane, the performance of directly blending salicylic acid and modified amino-terminated hyperbranched polysiloxane is slightly worse, because after salicylic acid is grafted onto the hyperbranched polysiloxane, it can be more evenly dispersed in the epoxy resin, thus playing a better role. In addition, the adhesives prepared by the present invention have a certain absorption effect on ultraviolet light, especially ultraviolet light with a wavelength of 260-350 nm, so they have good anti-ultraviolet aging performance.

[0081] Finally, it should be noted that the above are only the preferred embodiments of the present invention and are not intended to limit the present invention. Although the present invention has been described in detail with reference to the foregoing embodiments, those skilled in the art can still modify the technical solutions described in the foregoing embodiments, or perform equivalent replacements on some of the technical features. 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. An automatic glue - sticking process for a thermal protector, Characterized in that: It includes the following steps: Step 1: Take a certain amount of 3 - aminopropyltriethoxysilane, add deionized water, stir evenly to obtain a mixed solution A. Add hydrochloric acid solution to adjust the pH value of the system, raise the temperature in a water bath for reaction, evaporate the solvent to dryness, and dry it under vacuum to obtain a viscous liquid, which is amino - terminated hyperbranched polysiloxane; Step 2: Add N, N - dicyclohexylcarbodiimide and 1 - hydroxybenzotriazole to dichloromethane, stir until completely dissolved, add salicylic acid, stir for 2 h under an ice - water bath condition, and then dropwise add amino - terminated hyperbranched polysiloxane and stir to obtain a mixed solution B; Raise the temperature of the mixed solution B for reaction, rotate and evaporate to remove the solvent to obtain salicylic - acid - grafted modified amino - terminated hyperbranched polysiloxane; Step 3: Mix and stir evenly E51 epoxy resin, salicylic - acid - grafted modified amino - terminated hyperbranched polysiloxane, dicyandiamide, imidazole, alumina powder, boron nitride powder, defoamer, and dispersant to obtain an adhesive; Step 4: Coat the adhesive on a polyvinyl chloride film, cut and process to obtain the glue - sticking material for the thermal protector, and stick it on the thermal protector through an automatic glue - sticking machine.

2. The automatic glue - sticking process for a thermal protector according to claim 1, Characterized in that: In Step 1, in the mixed solution A, the content of each component, by weight, is 30 - 40 parts of 3 - aminopropyltriethoxysilane and 60 - 80 parts of deionized water.

3. The automatic glue - sticking process for a thermal protector according to claim 1, Characterized in that: In Step 1, the pH value of the system adjusted by hydrochloric acid is 4 - 5.

4. The automatic glue - sticking process for a thermal protector according to claim 1, Characterized in that: In Step 1, the temperature of the water - bath heating is 50 - 60 °C, and the reaction time is 4 - 6 h.

5. The automatic glue - sticking process for a thermal protector according to claim 1, Characterized in that: In Step 2, in the mixed solution B, the content of each component, by weight, is 100 - 120 parts of N, N - dicyclohexylcarbodiimide, 70 - 130 parts of 1 - hydroxybenzotriazole, 280 - 300 parts of dichloromethane, 50 - 70 parts of salicylic acid, and 20 - 30 parts of amino - terminated hyperbranched polysiloxane.

6. The automatic glue - sticking process for a thermal protector according to claim 1, Characterized in that: In Step 2, the mixed solution B is heated to 20 - 30 °C, and the reaction time is 6 - 8 h.

7. The automatic glue - sticking process for a thermal protector according to claim 1, Characterized in that: In Step 3, in the adhesive, the content of each component, calculated by weight percentage, is 100 parts of E51 epoxy resin, 1.5 - 2.5 parts of salicylic - acid - grafted modified amino - terminated hyperbranched polysiloxane, 8 - 12 parts of dicyandiamide, 5 - 8 parts of imidazole, 20 - 30 parts of alumina powder, 50 - 56 parts of boron nitride powder, and 10 - 14 parts of defoamer.