High-temperature-resistant epoxy glue and preparation method thereof

Abstract

The invention relates to the technical field of adhesives, in particular to high-temperature-resistant epoxy glue and a preparation method thereof.The high-temperature-resistant epoxy glue comprises a component A and a component B. The component A comprises, by mass, 100 parts of TDE-86 epoxy resin, 60-80 parts of silicon modified epoxy resin, 10-20 parts of reactive diluent, 10-20 parts of diethylene glycol dibenzoate and 50-60 parts of filler; the component B is prepared from the following components in parts by mass: 60 to 90 parts of dicyandiamide curing agent, 12 to 18 parts of substituted urea accelerant and 50 to 60 parts of filler. Chemical bonds generated by modification of dicyandiamide and reaction of the dicyandiamide curing agent and epoxy resin, especially chemical bonds between amino and epoxy groups, have high thermal decomposition temperature, and the stable chemical bonds enable the material to maintain structural stability at high temperature and not prone to decomposition or softening, so that the service life of the material is prolonged, and the service life of the material is prolonged. The adaptability in a high-temperature environment is improved.

Description

Technical Field

[0001] The invention relates to the technical field of adhesives, in particular to a high temperature resistant epoxy adhesive and a preparation method thereof. Background Art

[0002] As electronic products continue to develop towards miniaturization, portability, high integration and multifunctionality, their heat generation gradually increases, and the operating temperature also rises accordingly. Existing epoxy resin adhesives can no longer meet the needs of electronic products in terms of high temperature resistance. Therefore, combined with the rapid development of electronic products and the characteristics of epoxy resin adhesives, it is particularly important to conduct in-depth research on their high temperature resistance. Summary of the invention

[0003] The object of the present invention is to provide a high temperature resistant epoxy adhesive and a preparation method thereof to solve the problems raised in the above background technology.

[0004] To achieve the above-mentioned purpose, on the one hand, the present invention provides the following technical solutions: a high temperature resistant epoxy adhesive, comprising component A and component B, wherein component A and component B are used in combination according to a mass ratio of 1:1 to 1.2, component A comprises the following components by mass: 100 parts of TDE-86 epoxy resin, 60 to 80 parts of silicon-modified epoxy resin, 10 to 20 parts of active diluent, 10 to 20 parts of diethylene glycol dibenzoate, and 50 to 60 parts of filler, and component B comprises the following components by mass: 60 to 90 parts of dicyandiamide curing agent, 12 to 18 parts of substituted urea accelerator, and 50 to 60 parts of filler;

[0005] The dicyandiamide curing agent is prepared by the following steps: (1) dissolving dicyandiamide and tetrabutylammonium chloride in an ethanol solution to obtain agent A, dissolving PEG in an ethanol solution to obtain agent B, wherein the mass concentration of PEG in agent B is 10% to 30%, wherein the mass of tetrabutylammonium chloride is 0.5% to 3% of the mass of dicyandiamide, and the mass ratio of dicyandiamide to PEG is 1:5 to 10; (2) slowly adding agent B into agent A at 60°C, heating to 70 to 80°C, stirring for 30 to 60 minutes, and obtaining a mixed solution; (3) transferring the mixed solution to an evaporation device, and gradually removing ethanol by reduced pressure distillation or a rotary evaporator.

[0006] Optionally, the epoxy value of the TDE-86 epoxy resin is 0.9 mol / 100 g, and the viscosity of the TDE-86 epoxy resin at 25° C. is 3000 mPa·s.

[0007] Optionally, the active diluent is one of butyl glycidyl ether, ethylene glycol diglycidyl ether, phenyl glycidyl ether, 1,4-butanediol diglycidyl ether, decyl glycidyl ether, neopentyl glycol diglycidyl ether, and resorcinol diglycidyl ether.

[0008] Optionally, the substituted urea accelerator is an aromatic substituted urea latent accelerator GLOC-800.

[0009] Optionally, the filler comprises the following components by mass percentage: 25% silicon micropowder, 25% fumed silica, 40% wollastonite powder and 10% calcium oxide.

[0010] On the other hand, the present invention also discloses a method for preparing the above-mentioned high temperature resistant epoxy adhesive, comprising the following steps:

[0011] S1. Prepare component A: add TDE-86 epoxy resin, silicon-modified epoxy resin and diethylene glycol dibenzoate into a stirrer, stir and mix at a speed of 800 to 1200 r / min for 30 to 60 min, then add active diluent and filler, stir and mix at a speed of 600 to 800 r / min for 60 to 120 min, vacuum degas, filter and package to obtain component A;

[0012] S2, preparing component B: adding dicyandiamide curing agent and substituted urea accelerator into a stirrer, stirring and mixing at a speed of 1000-1200 r / min for 30-60 min, then adding filler, stirring and mixing at a speed of 600-800 r / min for 60-120 min, vacuum degassing, filtering and packaging to obtain component B;

[0013] S3, mixing: mixing component A with component B to obtain high temperature resistant epoxy adhesive.

[0014] Compared with the prior art, the present invention has the following beneficial effects:

[0015] 1. The present invention modifies dicyandiamide, and the chemical bonds generated by the reaction of dicyandiamide curing agent and epoxy resin, especially the chemical bonds between amino groups and epoxy groups, have a higher thermal decomposition temperature. Such stable chemical bonds enable the material to maintain structural stability at higher temperatures, and are not prone to decomposition or softening, thereby improving its adaptability in high-temperature environments. 2. The present invention adds dicyandiamide curing agent and an appropriate amount of filler to the formula, which not only improves the tensile strength and compressive strength of the cured material, but also enhances its impact resistance, thereby ensuring that the structural integrity can be maintained under high temperature and stress environments. DETAILED DESCRIPTION

[0016] 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 the embodiments. 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.

[0017] Embodiment 1: The present invention provides a high temperature resistant epoxy adhesive, comprising component A and component B, wherein component A and component B are used in a mass ratio of 1:1, component A comprises the following components by mass: 100 parts of TDE-86 epoxy resin, 60 parts of silicon-modified epoxy resin, 10 parts of reactive diluent, 10 parts of diethylene glycol dibenzoate, and 50 parts of filler, and component B comprises the following components by mass: 60 parts of dicyandiamide curing agent, 12 parts of substituted urea accelerator, and 50 parts of filler;

[0018] The dicyandiamide curing agent is prepared by the following steps: (1) dissolving dicyandiamide and tetrabutylammonium chloride in an ethanol solution to obtain agent A, dissolving PEG in an ethanol solution to obtain agent B, wherein the mass concentration of PEG in agent B is 10%, the mass of tetrabutylammonium chloride is 0.5% of the mass of dicyandiamide, and the mass ratio of dicyandiamide to PEG is 1:5; (2) slowly adding agent B into agent A at 60°C, heating to 70°C, stirring for 30 minutes, and obtaining a mixed solution; (3) transferring the mixed solution to an evaporator, and gradually removing ethanol by reduced pressure distillation.

[0019] Embodiment 2: The present invention provides a high temperature resistant epoxy adhesive, comprising component A and component B, wherein component A and component B are used in a mass ratio of 1:1.1, component A comprises the following components by mass: 100 parts of TDE-86 epoxy resin, 70 parts of silicon-modified epoxy resin, 15 parts of reactive diluent, 15 parts of diethylene glycol dibenzoate, and 55 parts of filler, and component B comprises the following components by mass: 70 parts of dicyandiamide curing agent, 14 parts of substituted urea accelerator, and 55 parts of filler;

[0020] The dicyandiamide curing agent is prepared by the following steps: (1) dissolving dicyandiamide and tetrabutylammonium chloride in an ethanol solution to obtain agent A, dissolving PEG in an ethanol solution to obtain agent B, wherein the mass concentration of PEG in agent B is 20%, the mass of tetrabutylammonium chloride is 1% of the mass of dicyandiamide, and the mass ratio of dicyandiamide to PEG is 1:7; (2) slowly adding agent B into agent A at 60°C, heating to 75°C, stirring for 40 minutes, and obtaining a mixed solution; (3) transferring the mixed solution to an evaporator, and gradually removing ethanol by reduced pressure distillation.

[0021] Embodiment 3: The present invention provides a high temperature resistant epoxy adhesive, comprising component A and component B, wherein component A and component B are used in a mass ratio of 1:1.1, component A comprises the following components by mass: 100 parts of TDE-86 epoxy resin, 78 parts of silicon-modified epoxy resin, 18 parts of reactive diluent, 18 parts of diethylene glycol dibenzoate, and 55 parts of filler, and component B comprises the following components by mass: 80 parts of dicyandiamide curing agent, 16 parts of substituted urea accelerator, and 55 parts of filler;

[0022] The dicyandiamide curing agent is prepared by the following steps: (1) dissolving dicyandiamide and tetrabutylammonium chloride in an ethanol solution to obtain agent A, dissolving PEG in an ethanol solution to obtain agent B, wherein the mass concentration of PEG in agent B is 25%, the mass of tetrabutylammonium chloride is 2% of the mass of dicyandiamide, and the mass ratio of dicyandiamide to PEG is 1:9; (2) slowly adding agent B into agent A at 60°C, heating to 78°C, stirring for 50 minutes, and obtaining a mixed solution; (3) transferring the mixed solution to an evaporator, and gradually removing ethanol by reduced pressure distillation.

[0023] Embodiment 4: The present invention provides a high temperature resistant epoxy adhesive, comprising component A and component B, wherein component A and component B are used in a mass ratio of 1:1.2, component A comprises the following components by mass: 100 parts of TDE-86 epoxy resin, 80 parts of silicon-modified epoxy resin, 20 parts of reactive diluent, 20 parts of diethylene glycol dibenzoate, and 60 parts of filler, and component B comprises the following components by mass: 90 parts of dicyandiamide curing agent, 18 parts of substituted urea accelerator, and 60 parts of filler;

[0024] The dicyandiamide curing agent is prepared by the following steps: (1) dissolving dicyandiamide and tetrabutylammonium chloride in an ethanol solution to obtain agent A, dissolving PEG in an ethanol solution to obtain agent B, wherein the mass concentration of PEG in agent B is 30%, wherein the mass of tetrabutylammonium chloride is 3% of the mass of dicyandiamide, and the mass ratio of dicyandiamide to PEG is 1:10; (2) slowly adding agent B into agent A at 60° C., heating to 80° C., stirring for 60 minutes, and obtaining a mixed solution; (3) transferring the mixed solution to an evaporator, and gradually removing ethanol by reduced pressure distillation.

[0025] In Examples 1 to 4, the epoxy value of TDE-86 epoxy resin is 0.9 mol / 100 g, and the viscosity of TDE-86 epoxy resin at 25° C. is 3000 mPa·s. The active diluent is butyl glycidyl ether. The substituted urea accelerator is an aromatic substituted urea latent accelerator GLOC-800. The filler includes the following components by mass percentage: 25% silicon micropowder, 25% fumed silica, 40% wollastonite powder, and 10% calcium oxide.

[0026] The present invention also discloses a method for preparing a high temperature resistant epoxy adhesive, comprising the following steps:

[0027] S1. Prepare component A: add TDE-86 epoxy resin, silicon-modified epoxy resin and diethylene glycol dibenzoate into a stirrer, stir and mix at a speed of 1000 r / min for 45 min, then add active diluent and filler, stir and mix at a speed of 750 r / min for 90 min, vacuum degas, filter and package to obtain component A;

[0028] S2, prepare component B: add dicyandiamide curing agent and substituted urea accelerator into a stirrer, stir and mix at a speed of 1100r / min for 45min, then add filler, stir and mix at a speed of 750r / min for 92min, vacuum degassing, filtering and packaging to obtain component B;

[0029] S3, mixing: mixing component A with component B to obtain high temperature resistant epoxy adhesive.

[0030] Examples 1 to 4 can all use the above-mentioned preparation method to prepare the high temperature resistant epoxy adhesive disclosed in the present invention.

[0031] Test example: The high temperature resistant epoxy adhesive obtained by the above preparation method in Examples 1 to 4 was tested for bonding strength (expressed as shear strength) using a universal testing machine according to the method disclosed in GB / T7124-1986. Another high temperature resistant epoxy adhesive obtained by the above preparation method in Examples 1 to 4 was cured at 80°C for 1 hour, then cured at 150°C for 1 hour, and finally cooled naturally to room temperature. The cured high temperature resistant epoxy adhesive was heat treated at 300°C for 30 minutes in a blast drying oven, and the bonding strength was tested again after cooling. The bonding strength retention rate (unit %) was calculated, and the results were recorded in Table 1.

[0032] Table 1

[0033] Bond strength / MPa Bond strength retention rate / % Example 1 17.88 89.8 Example 2 17.98 90.2 Example 3 18.01 90.9 Example 4 18.12 91.7

[0034] It can be seen from the above table that the high temperature resistant epoxy adhesives obtained by the above preparation method in Examples 1 to 4 have excellent high temperature resistance and bonding strength.

[0035] Although embodiments of the present invention have been shown and described, it will be appreciated by those skilled in the art that various changes, modifications, substitutions and variations may be made to the embodiments without departing from the principles and spirit of the present invention, and that the scope of the present invention is defined by the appended claims and their equivalents.

Claims

1. A high temperature resistant epoxy adhesive, comprising component A and component B, characterized in that: Component A and component B are used in a mass ratio of 1:1-1.

2. Component A includes the following components by mass: 100 parts of TDE-86 epoxy resin, 60-80 parts of silicon-modified epoxy resin, 10-20 parts of reactive diluent, 10-20 parts of diethylene glycol dibenzoate, and 50-60 parts of filler. Component B includes the following components by mass: 60-90 parts of dicyandiamide curing agent, 12-18 parts of substituted urea accelerator, and 50-60 parts of filler. The dicyandiamide curing agent is prepared by the following steps: (1) dissolving dicyandiamide and tetrabutylammonium chloride in an ethanol solution to obtain agent A, dissolving PEG in an ethanol solution to obtain agent B, wherein the mass concentration of PEG in agent B is 10% to 30%, wherein the mass of tetrabutylammonium chloride is 0.5% to 3% of the mass of dicyandiamide, and the mass ratio of dicyandiamide to PEG is 1:5 to 10; (2) slowly adding agent B into agent A at 60°C, heating to 70 to 80°C, stirring for 30 to 60 minutes, and obtaining a mixed solution; (3) transferring the mixed solution to an evaporation device, and gradually removing ethanol by reduced pressure distillation or a rotary evaporator.

2. A high temperature resistant epoxy adhesive according to claim 1, characterized in that: The epoxy value of the TDE-86 epoxy resin is 0.9 mol / 100 g, and the viscosity of the TDE-86 epoxy resin at 25° C. is 3000 mPa·s.

3. A high temperature resistant epoxy adhesive according to claim 1, characterized in that: The active diluent is one of butyl glycidyl ether, ethylene glycol diglycidyl ether, phenyl glycidyl ether, 1,4-butanediol diglycidyl ether, decyl glycidyl ether, neopentyl glycol diglycidyl ether and resorcinol diglycidyl ether.

4. The high temperature resistant epoxy adhesive according to claim 1, characterized in that: The substituted urea accelerator is an aromatic substituted urea latent accelerator GLOC-800.

5. The high temperature resistant epoxy adhesive according to claim 1, characterized in that: The filler comprises the following components by mass percentage: 25% of silicon micropowder, 25% of fumed white carbon black, 40% of wollastonite powder and 10% of calcium oxide.

6. The method for preparing the high temperature resistant epoxy adhesive according to any one of claims 1 to 5, characterized in that: The following steps are involved: S1. Prepare component A: add TDE-86 epoxy resin, silicon-modified epoxy resin and diethylene glycol dibenzoate into a stirrer, stir and mix at a speed of 800 to 1200 r / min for 30 to 60 min, then add active diluent and filler, stir and mix at a speed of 600 to 800 r / min for 60 to 120 min, vacuum degas, filter and package to obtain component A; S2, preparing component B: adding dicyandiamide curing agent and substituted urea accelerator into a stirrer, stirring and mixing at a speed of 1000-1200 r / min for 30-60 min, then adding filler, stirring and mixing at a speed of 600-800 r / min for 60-120 min, vacuum degassing, filtering and packaging to obtain component B; S3, mixing: mixing component A with component B to obtain high temperature resistant epoxy adhesive.