Halogen-free flux for tin paste and preparation method thereof

Abstract

The present application relates to the technical field of soldering paste, and particularly relates to a halogen-free flux for soldering paste and a preparation method thereof.The raw materials of the halogen-free flux for soldering paste include, by mass fraction, hydrogenated rosin 20-40 parts, maleic anhydride 1-5 parts, p-toluenesulfonic acid 0.1-0.4 parts, activated mesoporous silica 1-5 parts, composite organic acid activator 10-20 parts, thixotropic agent 5-10 parts, tackifier 1-3 parts, pH regulator 1-2 parts, surfactant 1-2 parts, chelating agent 1-2 parts, antioxidant 1-2 parts, and organic solvent 50-80 parts.The present application effectively solves the long-standing technical contradiction in the field of halogen-free flux through innovative component design and preparation process, and provides an ideal material solution for high-reliability electronic packaging.

Description

TECHNICAL FIELD

[0001] The present application relates to the technical field of soldering paste, in particular to a halogen-free flux for soldering paste and a preparation method thereof. BACKGROUND

[0002] With the development of electronic packaging industry towards high density and miniaturization, the performance requirements of flux for soldering paste are increasingly stringent. Traditional halogen-containing flux is gradually replaced by halogen-free flux because halogen ions remaining in the traditional halogen-containing flux can easily cause corrosion of circuit boards. However, the existing halogen-free flux still has many technical bottlenecks that need to be broken through.

[0003] The flux for soldering paste is usually composed of solvents, resins, surfactants, activators, antioxidants, and thixotropic agents. Different components play different roles, and each component forms a whole that influences each other. In the traditional system, halogen-based activators represented by organic amine halide (such as diethylamine hydrochloride and triethylamine hydrobromide) have excellent soldering activity, can achieve rapid soldering and good soldering effect, but the residual halogen ions can cause double harm: on the one hand, during the service period of electronic products, the residual substances can easily cause corrosion of circuit boards; on the other hand, during the disposal of waste, polybrominated diphenyl ethers and other halogenated compounds are difficult to degrade, can pollute the ecological chain through groundwater, and finally accumulate in human adipose tissue, causing persistent health damage.

[0004] As an activator component, organic acid is used in the preparation of halogen-free flux due to its low corrosion and high reliability. However, the acidic components remaining after welding of the organic acid activator can still cause corrosion of the circuit board in a humid and hot environment, and its activity is significantly inferior to that of the traditional halogen-based activator, which makes it difficult to achieve ideal electrical performance and reliability after welding. SUMMARY

[0005] The present application aims to solve the problems in the prior art and provides a halogen-free flux for soldering paste and a preparation method thereof.

[0006] A halogen-free flux for soldering paste, the raw materials of which include, by mass fraction: hydrogenated rosin 20-40 parts, maleic anhydride 1-5 parts, p-toluenesulfonic acid 0.1-0.4 parts, activated mesoporous silica 1-5 parts, composite organic acid activator 10-20 parts, thixotropic agent 5-10 parts, tackifier 1-3 parts, pH adjuster 1-2 parts, surfactant 1-2 parts, chelating agent 1-2 parts, antioxidant 1-2 parts, and organic solvent 50-80 parts.

[0007] Preferably, the activated mesoporous silica is mesoporous silica activated by silane coupling agent KH550.

[0008] The BET specific surface area of the mesoporous silica is 500-800 m 2 / g.

[0009] Preferably, the composite organic acid active agent comprises 2-ethylhexanoic acid, sebacic acid, nano cerium oxide; the mass ratio of 2-ethylhexanoic acid, sebacic acid, nano cerium oxide is 10:1-5:0.1-1.

[0010] Preferably, the thixotropic agent is oxidized polyethylene wax and / or hydrogenated castor oil.

[0011] Preferably, the tackifier comprises at least one of hydrogenated rosin glyceride, benzene melamine, erucic acid amide.

[0012] Preferably, the pH regulator is triisopropanolamine.

[0013] Preferably, the antioxidant is antioxidant 1010 and / or antioxidant 246.

[0014] Preferably, the organic solvent is at least one of diethylene glycol diethyl ether, hexyl diglycol, isodecyl alcohol, isophorone.

[0015] Preferably, the surfactant is a fatty alcohol polyoxyethylene ether.

[0016] Preferably, the chelating agent is disodium EDTA.

[0017] The preparation method of the above-mentioned halogen-free flux for tin paste comprises the following steps:

[0018] S1, hydrogenated rosin, maleic anhydride, p-toluenesulfonic acid are added to toluene, refluxed at 120-140 DEG C under nitrogen protection for 2-4h, cooled to 50-60 DEG C, deionized water is added and stirred for 10-20min, the lower water phase is removed by liquid separation, toluene is removed by reduced pressure distillation, and vacuum drying; mixed with activated mesoporous silica, ball milled for 1-2h under nitrogen protection, added to an organic solvent, heated and stirred to dissolve to obtain a mixture;

[0019] S2, adjust the temperature of the mixture to 90-100 DEG C, add the composite organic acid active agent and antioxidant and stir uniformly, adjust the temperature to 60-70 DEG C, add the thixotropic agent, tackifier, pH regulator, surfactant and chelating agent and stir uniformly.

[0020] Beneficial effects:

[0021] The present application adopts 2-ethylhexanoic acid and sebacic acid to form a eutectic system to reduce the overall melting point in the initial stage, and gradually release the activity above 210 DEG C, and provide excellent oxide removal capacity, nano cerium oxide forms coordination with carboxylate through surface oxygen vacancies, delays the volatilization of organic acid at low temperature stage, and releases active ingredients at high temperature, realizes phased activation, greatly enhances the activity of the flux, and reduces the content of ionizable acidic substances.

[0022] The present application utilizes hydrogenated rosin combined with maleic anhydride to generate modified rosin with a three-dimensional network structure, and embeds mesoporous silica into the gap of the rosin molecular chain, not only to generate exhaust passages during welding, promote the rapid escape of volatile substances, reduce the accumulation of volatile residues, and ensure the post-weld surface cleaning, but also to cooperate with the composite organic acid active agent to make the system have good wettability, small corrosion to the solder joint, and can significantly improve the surface insulation resistance; further cooperating with triisopropanolamine and chelating agent, the residual acid can be further neutralized, the metal ions can be chelated, and the electrochemical corrosion in the wet heat environment can be reduced.

[0023] The present application not only does not contain halogen compounds, is green and environmentally friendly, but also the mesoporous silica exhaust passage promotes wettability, the post-weld residue is light and clear, and the electrical performance meets the high reliability requirement, effectively improving the soldering performance of the soldering paste.

[0024] The present application effectively solves the long-existing technical contradiction in the field of halogen-free flux by innovative component design and preparation process, and provides an ideal material solution for high-reliability electronic packaging. BRIEF DESCRIPTION OF DRAWINGS

[0025] Figure 1 The expansion rate comparison chart of the fluxes obtained in Example 5 and Comparative Examples 1-2.

[0026] Figure 2 The surface insulation resistance and organic residue rate comparison chart of the soldering pastes of Example 5 group and Comparative Examples 1-2 group. DETAILED DESCRIPTION

[0027] The present application will be further described below in combination with specific embodiments.

[0028] Example 1

[0029] A halogen-free flux for soldering paste, raw materials of which include: hydrogenated rosin 20g, maleic anhydride 1g, p-toluenesulfonic acid 0.1g, activated mesoporous silica 1g, composite organic acid active agent 10g, hydrogenated castor oil 5g, hydrogenated rosin glyceride 1g, triisopropanolamine 1g, AEO-9 1g, EDTA disodium salt 1g, antioxidant 1010 1g, and diethylene glycol diethyl ether 50g.

[0030] The activated mesoporous silica is obtained by mixing silane coupling agent KH550 and mesoporous silica at a mass ratio of 0.05:10. The composite organic acid active agent is composed of 2-ethylhexanoic acid, sebacic acid, and nano cerium oxide at a mass ratio of 10:1:0.1.

[0031] The preparation method of the above-mentioned halogen-free flux for soldering paste includes the following steps:

[0032] S1, hydrogenated rosin, maleic anhydride, p-toluenesulfonic acid is added to 100g of toluene, under nitrogen protection, at a temperature of 120℃ reflux reaction 2h, cooling to 50℃, stirring for 10min, removing the lower aqueous phase by liquid-liquid separation, removing toluene by distillation under reduced pressure, vacuum drying; add activated mesoporous silica mixture, ball milling under nitrogen protection at a speed of 200r / min for 1h, ball to material ratio is 10:1, add to diethylene glycol diethyl ether, heating and stirring to dissolve to obtain a mixture;

[0033] S2, adjust the temperature of the mixture to 90℃, add the composite organic acid active agent, antioxidant 1010 and stir evenly, adjust the temperature to 60℃, add hydrogenated castor oil, hydrogenated rosin glyceride, triisopropanolamine, AEO-9, EDTA disodium salt and stir evenly.

[0034] Example 2

[0035] A halogen-free flux for tin paste, the raw materials of which include: hydrogenated rosin 40g, maleic anhydride 5g, p-toluenesulfonic acid 0.4g, activated mesoporous silica 5g, composite organic acid active agent 20g, hydrogenated castor oil 10g, benzene triazine 3g, triisopropanolamine 2g, AEO-9 2g, EDTA disodium salt 2g, antioxidant 246 2g, hexyl diethylene glycol 80g.

[0036] The activated mesoporous silica is obtained by mixing silane coupling agent KH550 with mesoporous silica at a mass ratio of 0.15:10. The composite organic acid active agent is composed of 2-ethylhexanoic acid, sebacic acid and nano cerium oxide at a mass ratio of 10:5:1.

[0037] The preparation method of the above-mentioned halogen-free flux for tin paste comprises the following steps:

[0038] S1, hydrogenated rosin, maleic anhydride, p-toluenesulfonic acid is added to 100g of toluene, under nitrogen protection, at a temperature of 120℃ reflux reaction 2h, cooling to 50℃, stirring for 10min, removing the lower aqueous phase by liquid-liquid separation, removing toluene by distillation under reduced pressure, vacuum drying; add activated mesoporous silica mixture, ball milling under nitrogen protection at a speed of 200r / min for 1h, ball to material ratio is 10:1, add to diethylene glycol diethyl ether, heating and stirring to dissolve to obtain a mixture;

[0039] S2, adjust the temperature of the mixture to 90℃, add the composite organic acid active agent, antioxidant 1010 and stir evenly, adjust the temperature to 60℃, add hydrogenated castor oil, hydrogenated rosin glyceride, triisopropanolamine, AEO-9, EDTA disodium salt and stir evenly.

[0040] Example 3

[0041] A halogen-free flux for tin paste, raw materials of which include: hydrogenated rosin 25g, maleic anhydride 4g, p-toluene sulfonic acid 0.2g, activated mesoporous silica 4g, composite organic acid activator 12g, oxidized polyethylene wax 9g, erucic acid amide 1.5g, triisopropanolamine 1.8g, AEO-9 1.3g, disodium EDTA 1.8g, antioxidant 1010 1.3g, isodecyl alcohol 70g.

[0042] The activated mesoporous silica is obtained by mixing silane coupling agent KH550 and mesoporous silica at a mass ratio of 0.08:10. The composite organic acid activator is composed of 2-ethylhexanoic acid, sebacic acid and nano cerium oxide at a mass ratio of 10:4:0.3.

[0043] The preparation method of the above-mentioned halogen-free flux for tin paste comprises the following steps:

[0044] S1, hydrogenated rosin, maleic anhydride, p-toluene sulfonic acid are added to 180g of toluene, and refluxed at 125℃ under nitrogen protection for 3.5h, cooled to 52℃, 90g of deionized water is added and stirred for 12min, the lower aqueous phase is removed by liquid-liquid separation, toluene is removed by vacuum distillation, and vacuum drying is carried out; the activated mesoporous silica is mixed, ball milled at a speed of 280r / min under nitrogen protection for 80min, the ball-to-material ratio is 10:1.7, and then added to isodecyl alcohol, heated and stirred to dissolve to obtain a mixture;

[0045] S2, the temperature of the mixture is adjusted to 92℃, the composite organic acid activator, antioxidant 1010 are added and stirred uniformly, the temperature is adjusted to 68℃, and the oxidized polyethylene wax, erucic acid amide, triisopropanolamine, AEO-9, disodium EDTA are added and stirred uniformly.

[0046] Example 4

[0047] A halogen-free flux for tin paste, raw materials of which include: hydrogenated rosin 35g, maleic anhydride 2g, p-toluene sulfonic acid 0.3g, activated mesoporous silica 2g, composite organic acid activator 18g, oxidized polyethylene wax 7g, benzene trimerized melamine 2.5g, triisopropanolamine 1.2g, AEO-9 1.7g, disodium EDTA 1.2g, antioxidant 246 1.7g, isophorone 60g.

[0048] The activated mesoporous silica is obtained by mixing silane coupling agent KH550 and mesoporous silica at a mass ratio of 0.12:10. The composite organic acid activator is composed of 2-ethylhexanoic acid, sebacic acid and nano cerium oxide at a mass ratio of 10:2:0.7.

[0049] The preparation method of the above-mentioned halogen-free flux for tin paste comprises the following steps:

[0050] S1, hydrogenated rosin, maleic anhydride, p-toluenesulfonic acid is added to 120 g of toluene, under nitrogen protection, reflux reaction at 135℃ for 2.5h, cooling to 58℃, 70 g of deionized water is added and stirred for 18 min, remove the lower aqueous phase by liquid-liquid separation, remove toluene by reduced pressure distillation, vacuum drying; add activated mesoporous silica and mix, ball mill under nitrogen protection at a speed of 220 r / min for 100 min, ball to material ratio is 10:1.3, add to isophorone, heat and stir to dissolve to obtain a mixture;

[0051] S2, adjust the temperature of the mixture to 98℃, add the composite organic acid active agent, antioxidant 246 and stir evenly, adjust the temperature to 62℃, add oxidized polyethylene wax, benzotriazine, triisopropanolamine, AEO-9, EDTA disodium salt and stir evenly.

[0052] Example 5

[0053] A halogen-free flux for tin paste, the raw materials of which include: hydrogenated rosin 30 g, maleic anhydride 3 g, p-toluenesulfonic acid 0.25 g, activated mesoporous silica 3 g, composite organic acid active agent 15 g, oxidized polyethylene wax 8 g, hydrogenated rosin glyceride 2 g, triisopropanolamine 1.5 g, AEO-9 1.5 g, EDTA disodium salt 1.5 g, antioxidant 1010 1.5 g, diethylene glycol diethyl ether 65 g.

[0054] The activated mesoporous silica is prepared by dispersing mesoporous silica in toluene, adding silane coupling agent KH550, refluxing at a temperature of 80-100℃ for 2-4h, filtering, washing, and vacuum drying. The mass ratio of silane coupling agent KH550 to mesoporous silica is 0.1:10.

[0055] The composite organic acid active agent is composed of 2-ethylhexanoic acid, sebacic acid, and nano cerium oxide in a mass ratio of 10:3:0.5. During preparation, the nano cerium oxide, 2-ethylhexanoic acid, and sebacic acid are mixed according to the ratio and sent to a ball mill for processing for 12 min (ball to material ratio of 8:1, 200 r / min).

[0056] The preparation method of the above-mentioned halogen-free flux for tin paste includes the following steps:

[0057] S1, hydrogenated rosin, maleic anhydride, p-toluenesulfonic acid is added to 150g of toluene, under nitrogen protection, reflux reaction at temperature 130℃ for 3h, cooling to 55℃, stirring for 15min, removing the lower aqueous phase by liquid-liquid separation, adjusting the pH value of the system to neutral, removing toluene by vacuum distillation, vacuum drying; adding activated mesoporous silica, mixing, ball milling under nitrogen protection at a speed of 260r / min for 90min, ball-to-material ratio is 10:1.5, ball milling medium is zirconia ball, ball milling vacuum degree is 10-50Pa, adding to diethylene glycol diethyl ether, heating and stirring to dissolve to obtain a mixture;

[0058] S2, adjusting the temperature of the mixture to 95℃, adding composite organic acid active agent, antioxidant 1010, stirring uniformly, adjusting the temperature to 65℃, adding oxidized polyethylene wax, hydrogenated rosin glyceride, triisopropanolamine, AEO-9, EDTA disodium salt, stirring uniformly.

[0059] Comparative example 1

[0060] A halogen-free flux for tin paste, raw materials including: hydrogenated rosin 30g, maleic anhydride 3g, p-toluenesulfonic acid 0.25g, activated mesoporous silica 3g, composite organic acid active agent 15g, oxidized polyethylene wax 8g, hydrogenated rosin glyceride 2g, triisopropanolamine 1.5g, AEO-9 1.5g, EDTA disodium salt 1.5g, antioxidant 1010 1.5g, diethylene glycol diethyl ether 65g.

[0061] The activated mesoporous silica is prepared by dispersing mesoporous silica in toluene, adding silane coupling agent KH550, refluxing at a temperature of 80-100℃ for 2-4h, filtering, washing, and vacuum drying. The mass ratio of silane coupling agent KH550 to mesoporous silica is 0.1:10.

[0062] The composite organic acid active agent is composed of 2-ethylhexanoic acid and sebacic acid at a mass ratio of 10:3.

[0063] The preparation method of the above-mentioned halogen-free flux for tin paste comprises the following steps:

[0064] S1, hydrogenated rosin, maleic anhydride, p-toluenesulfonic acid is added to 150g of toluene, under nitrogen protection, reflux reaction at temperature 130℃ for 3h, cooling to 55℃, stirring for 15min, removing the lower aqueous phase by liquid-liquid separation, adjusting the pH value of the system to neutral, removing toluene by vacuum distillation, vacuum drying; adding activated mesoporous silica, mixing, ball milling under nitrogen protection at a speed of 260r / min for 90min, ball-to-material ratio is 10:1.5, adding to diethylene glycol diethyl ether, heating and stirring to dissolve to obtain a mixture;

[0065] S2, adjust the temperature of the mixture to 95℃, add the composite organic acid active agent, antioxidant 1010 and stir until uniform, adjust the temperature to 65℃, add the oxidized polyethylene wax, hydrogenated rosin glyceride, triisopropanolamine, AEO-9, and disodium EDTA salt and stir until uniform.

[0066] Comparative Example 2

[0067] A halogen-free flux for tin paste, the raw materials of which include: hydrogenated rosin 30g, maleic anhydride 3g, p-toluenesulfonic acid 0.25g, activated mesoporous silica 3g, composite organic acid active agent 15g, oxidized polyethylene wax 8g, hydrogenated rosin glyceride 2g, triisopropanolamine 1.5g, AEO-9 1.5g, disodium EDTA salt 1.5g, antioxidant 1010 1.5g, and diethylene glycol diethyl ether 65g.

[0068] The activated mesoporous silica is prepared by dispersing mesoporous silica in toluene, adding silane coupling agent KH550, refluxing at a temperature of 80-100℃ for 2-4h, filtering, washing, and vacuum drying. The mass ratio of silane coupling agent KH550 to mesoporous silica is 0.1:10.

[0069] The composite organic acid active agent is composed of 2-ethylhexanoic acid, sebacic acid, and nano cerium oxide in a mass ratio of 10:3:0.5; during preparation, the nano cerium oxide, 2-ethylhexanoic acid, and sebacic acid are mixed according to the ratio and sent into a ball mill for processing for 12min (ball-to-material ratio 8:1, 200r / min).

[0070] The preparation method of the above-mentioned halogen-free flux for tin paste includes the following steps:

[0071] S1, hydrogenated rosin, maleic anhydride, and p-toluenesulfonic acid are added to 150g of toluene, and refluxed at a temperature of 130℃ for 3h under nitrogen protection, then cooled to 55℃, 80g of deionized water is added and stirred for 15min, the lower aqueous phase is removed by liquid-liquid separation, the pH value of the system is adjusted to neutral, toluene is removed by vacuum distillation, vacuum dried, and added to diethylene glycol diethyl ether, heated and stirred to dissolve to obtain a mixture;

[0072] S2, adjust the temperature of the mixture to 95℃, add the composite organic acid active agent, antioxidant 1010 and stir until uniform, adjust the temperature to 65℃, add the activated mesoporous silica, ball mill at a speed of 260r / min for 90min, ball-to-material ratio is 10:1.5, add the oxidized polyethylene wax, hydrogenated rosin glyceride, triisopropanolamine, AEO-9, and disodium EDTA salt and stir until uniform.

[0073] The performance of the fluxes obtained in Example 5 and Comparative Examples 1-2 was detected. Among them, the expansion rate was tested according to IPC-J-STD-004B "Flux Requirements", and the copper mirror corrosion was tested according to IPC-TM-650.

[0074] The results are shown in Table 1 and Figure 1 As shown in Table 1 and

[0075] Table 1 Properties of the fluxes obtained in Example 5 and Comparative Examples 1-2

[0076]

[0077]

[0078] Note: * represents the amount of smoke, the more the better.

[0079] The fluxes obtained in Example 5, Comparative Examples 1-2 and tin-based alloy powder (SnCu 0.7 ) were mixed in a mass ratio of 5:95 to form solder paste, and then each group of solder paste was tested according to SJ / T 11186-2019 "General Specification for Solder Paste". The solder paste in Example 5 had a tin bead level and wettability of 1 grade; the solder paste in Comparative Example 1 had a tin bead level of 2 grade and a wettability of 1 grade; and the solder paste in Comparative Example 2 had a tin bead level and wettability of 2 grade.

[0080] A vertical laser reflow soldering furnace was used, a PCB aluminum substrate was set, the temperature in the laser area was controlled at 260±10℃, the solder paste in Example 5 and Comparative Examples 1-2 was pre-coated, then manual placement and reflow soldering were performed, and a 1mm×5mm×50mm wire was welded; and the wire surface insulation resistance was tested according to the IPC-TM-650 standard. After the welding of each group was completed, the wire was cleaned and dried, the total weight of the wire was tested, and the organic residue rate was calculated.

[0081] Organic residue rate = (total weight of the wire - mass of the tin-based alloy powder) ÷ (mass of the solder paste - mass of the tin-based alloy powder) × 100%

[0082] As shown in Table 1 and Figure 2 The surface insulation resistance of the solder paste in Example 5 was the highest, and the organic residue rate was the smallest, which was better than that of Comparative Examples 1-2 (P<0.05).

[0083] The above is only a preferred specific embodiment of the present application, but the protection scope of the present application is not limited thereto, any person skilled in the art can make equivalent replacement or change according to the technical solution and inventive concept of the present application within the technical range disclosed by the present application, which should be covered within the protection scope of the present application.

Claims

1. A halogen-free flux for a tin paste, characterized by, The raw materials include, by mass fraction: hydrogenated rosin 20-40 parts, maleic anhydride 1-5 parts, p-toluenesulfonic acid 0.1-0.4 parts, activated mesoporous silica 1-5 parts, composite organic acid activator 10-20 parts, thixotropic agent 5-10 parts, tackifier 1-3 parts, pH regulator 1-2 parts, surfactant 1-2 parts, chelating agent 1-2 parts, antioxidant 1-2 parts, organic solvent 50-80 parts.

2. The halogen-free flux for solder paste according to claim 1, wherein The activated mesoporous silica is mesoporous silica activated by silane coupling agent KH550.

3. The halogen-free flux for solder paste according to claim 1, wherein The composite organic acid activator includes 2-ethylhexanoic acid, sebacic acid, and nano cerium oxide, and the mass ratio of 2-ethylhexanoic acid, sebacic acid, and nano cerium oxide is 10:1-5:0.1-1.

4. The halogen-free flux for solder paste according to claim 1, wherein The thixotropic agent is oxidized polyethylene wax and / or hydrogenated castor oil.

5. The halogen-free flux according to claim 1, wherein The tackifier includes at least one of hydrogenated rosin glyceride, benzene melamine, and erucic amide. The pH regulator is triisopropanolamine.

6. The halogen-free flux according to claim 1, wherein The antioxidant is antioxidant 1010 and / or antioxidant 246.

7. The halogen-free flux according to claim 1, wherein The organic solvent is at least one of diethylene glycol diethyl ether, hexyl diglycol, isodecyl alcohol, and isophorone.

8. The halogen-free flux according to claim 1, wherein The surfactant is fatty alcohol polyoxyethylene ether, and the chelating agent is disodium EDTA.

9. The halogen-free flux according to claim 1, wherein The method includes the following steps:

10. A process for producing the halogen-free flux for a tin paste according to any one of claims 1 to 9, characterized by, S1, hydrogenated rosin, maleic anhydride, and p-toluenesulfonic acid are added to toluene, and refluxed at 120-140°C under nitrogen protection for 2-4h, cooled to 50-60°C, and then deionized water is added and stirred for 10-20min, the lower aqueous phase is removed by liquid-liquid separation, toluene is removed by reduced pressure distillation, and vacuum drying is performed; activated mesoporous silica is added and mixed, ball milled for 1-2h under nitrogen protection, and then added to an organic solvent, heated and stirred to dissolve to obtain a mixture; S2, the temperature of the mixture is adjusted to 90-100°C, the composite organic acid activator and antioxidant are added and stirred uniformly, the temperature is adjusted to 60-70°C, and the thixotropic agent, tackifier, pH regulator, surfactant, and chelating agent are added and stirred uniformly. ​

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