Preparation method of epoxy resin adhesive

Abstract

The invention relates to the technical field of adhesives, and discloses a preparation method of an epoxy resin adhesive, which comprises the following steps: reacting p-aminophenol with diphenyl dichlorosilane under the catalysis of triethanolamine to obtain di (p-aminophenoxy) diphenyl silane; the preparation method comprises the following steps: carrying out Mannich reaction on amino in di (p-aminophenoxy) diphenyl silane, amino in polyether amine, formaldehyde and phenol to obtain the silane-containing polyether amine type benzoxazine intermediate. And finally, uniformly mixing the silane-containing polyether amine type benzoxazine intermediate and epoxy resin, and curing to obtain the epoxy resin adhesive. The prepared silane-containing polyether amine benzoxazine intermediate contains a silane structure and a benzoxazine structure, both the silane structure and the benzoxazine structure have excellent heat resistance, and the epoxy resin adhesive prepared by adding the silane-containing polyether amine benzoxazine intermediate into epoxy resin has excellent heat resistance.

Description

TECHNICAL FIELD

[0001] The present application relates to the technical field of adhesives, in particular to a preparation method of an epoxy resin adhesive. BACKGROUND

[0002] Adhesive is a kind of material that can connect two or more materials together through the adhesion and cohesion of the interface. Epoxy resin is a kind of thermosetting resin containing two or more epoxy groups, which has excellent mechanical properties, bonding properties, insulation properties and other properties. Epoxy resin adhesive has low cost, high bonding strength and excellent comprehensive performance, and is widely used in fields such as aircraft, rockets, automobiles and electronics. However, its high temperature resistance is poor, so how to improve its heat resistance to expand its application field is one of the current research hotspots.

[0003] Benzoxazine is a kind of benzene derivative containing nitrogen and oxygen atoms, which can form a structure similar to phenolic resin through ring-opening polymerization, and has excellent flame retardant performance, heat resistance, mechanical properties and other properties, and is widely used in fields such as printed circuit boards and aerospace. Silane has excellent mechanical properties, thermal properties, toughness and other properties, and is widely used in microelectronics, machinery, chemical industry, optics and other fields. For example, the patent with the authorization announcement number CN113150501B discloses a benzoxazine flame-retardant modified epoxy resin for vacuum infusion molding and a preparation method. The invention adds benzoxazine resin, phosphate ester flame retardant, curing agent and accelerator to the epoxy resin to prepare a benzoxazine flame-retardant modified epoxy resin, which has low viscosity and excellent flame retardant performance, but does not improve its heat resistance. SUMMARY

[0004] (I) Technical problems to be solved In view of the shortcomings of the prior art, the present application provides a preparation method of an epoxy resin adhesive. The prepared epoxy resin adhesive has excellent heat resistance.

[0005] (II) Technical solutions A preparation method of an epoxy resin adhesive, the preparation method is: (1) Dissolve p-aminophenol and triethanolamine in tetrahydrofuran solvent, stir and disperse, then add diphenyldichlorosilane, heat and reflux, filter, wash with water, then dissolve it in petroleum ether, filter, recrystallize to obtain di(p-aminophenoxy)diphenylsilane, and the reaction equation is .

[0006] (2) Diphenylsilane, polyether amine, 30-40% formaldehyde solution is added to toluene solvent, stirring and dispersing for 40-80 min, phenol is added, stirring and reacting, rotary evaporation to remove the solvent, water washing, drying, to obtain a silane-containing polyether amine type benzoxazine intermediate.

[0007] (3) The silane-containing polyether amine type benzoxazine intermediate and the epoxy resin are mixed uniformly, heated to 80-100 ℃, preheated for 3-5 min, then diamino dimethyl is added, stirred uniformly, vacuum degassing, and curing in a drying oven to obtain an epoxy resin adhesive.

[0008] Preferably, the molar ratio of p-aminophenol, triethanolamine, and diphenyldichlorosilane in step (1) is 1.8-2.4:2-2.6:1.

[0009] Preferably, the reflux reaction time in step (1) is 30-50 h, and the temperature is 60-80 ℃.

[0010] Preferably, the molar ratio of diphenylsilane, polyether amine, and phenol in step (2) is 1:0.6-0.8:1.5-2.5.

[0011] Preferably, the stirring reaction time in step (2) is 5-8 h, and the temperature is 20-35 ℃.

[0012] Preferably, the curing process in step (3) is 160-170 ℃ / 1 h, 180-200 ℃ / 1 h, and 210-230 ℃ / 1 h.

[0013] Preferably, the mass ratio of the silane-containing polyether amine type benzoxazine intermediate, the epoxy resin, and 4,4-diamino diphenyl sulfone in step (3) is 0.2-0.6:1:0.8-1.2.

[0014] (Three) Beneficial technical effects P-aminophenol reacts with diphenyldichlorosilane under the catalysis of triethanolamine to obtain diphenylsilane, the amino group in diphenylsilane and the amino group in polyether amine undergo Mannich reaction with formaldehyde and phenol to obtain a silane-containing polyether amine type benzoxazine intermediate. Finally, the silane-containing polyether amine type benzoxazine intermediate and the epoxy resin are mixed uniformly, and cured to obtain an epoxy resin adhesive.

[0015] The silane polyether amine type benzoxazine intermediate prepared by the method has silane, and when heated, the siloxane bond has high bond energy and can absorb more heat, so that when the silane polyether amine type benzoxazine intermediate is added to the epoxy resin, the heat resistance of the epoxy resin can be increased. The epoxy resin adhesive prepared by the method has excellent heat resistance. DETAILED DESCRIPTION

[0016] The technical solutions in the embodiments of the present application will be clearly and completely described below. Obviously, the described embodiments are only some of the embodiments of the present application, but not all the embodiments. Based on the embodiments in the present application, all other embodiments obtained by those skilled in the art without creative work fall within the scope of protection of the present application.

[0017] Embodiment 1 (1) 120 mmol of p-aminophenol, 120 mmol of triethanolamine were dissolved in tetrahydrofuran solvent, stirred and dispersed, then 50 mmol of diphenyldichlorosilane was added, heated to 80°C, refluxed for 36 h, filtered, washed with water, then dissolved in petroleum ether, filtered, recrystallized to obtain diphenylsilane bis(p-aminophenoxy).

[0018] (2) 0.5 mol of diphenylsilane bis(p-aminophenoxy), 0.3 mol of polyether amine, 35% formaldehyde solution were added to toluene solvent, stirred and dispersed for 60 min, then 0.75 mol of phenol was added, stirred at 25°C for 8 h, the solvent was removed by rotary evaporation, washed with water and dried to obtain a silane-containing polyether amine type benzoxazine intermediate.

[0019] (3) 10 g of the silane-containing polyether amine type benzoxazine intermediate, 50 g of epoxy resin were mixed uniformly, heated to 100°C, preheated for 4 min, then 50 g of diamino dimethyl methane was added, stirred uniformly, vacuum degassed, and cured in a drying oven, with a curing process of 160°C / 1h, 180°C / 1h, 220°C / 1h to obtain an epoxy resin adhesive.

[0020] Embodiment 2 (1) 90 mmol of p-aminophenol, 130 mmol of triethanolamine were dissolved in tetrahydrofuran solvent, stirred and dispersed, 50 mmol of diphenyldichlorosilane was added thereto, warmed to 70°C, refluxed for 48 h, filtered, washed with water, dissolved in petroleum ether, filtered, recrystallized to obtain di(p-aminophenoxy)diphenylsilane.

[0021] (2) 0.5 mol of di(p-aminophenoxy)diphenylsilane, 0.35 mol of polyetheramine, 30% formaldehyde solution were added to toluene solvent, stirred and dispersed for 50 min, 0.8 mol of phenol was added thereto, stirred at 35°C for 6 h, the solvent was removed by rotary evaporation, washed with water, dried to obtain a silane-containing polyether amine type benzoxazine intermediate.

[0022] (3) 15 g of the silane-containing polyether amine type benzoxazine intermediate, 50 g of epoxy resin were uniformly mixed, warmed to 90°C, preheated for 5 min, 60 g of diaminodimethylmethane was added thereto, stirred uniformly, vacuum degassed, cured in a drying oven, the curing process was 170°C / 1 h, 200°C / 1 h, 230°C / 1 h to obtain an epoxy resin adhesive.

[0023] Example 3 (1) 100 mmol of p-aminophenol, 110 mmol of triethanolamine were dissolved in tetrahydrofuran solvent, stirred and dispersed, 50 mmol of diphenyldichlorosilane was added thereto, warmed to 80°C, refluxed for 50 h, filtered, washed with water, dissolved in petroleum ether, filtered, recrystallized to obtain di(p-aminophenoxy)diphenylsilane.

[0024] (2) 0.5 mol of di(p-aminophenoxy)diphenylsilane, 0.3 mol of polyetheramine, 40% formaldehyde solution were added to toluene solvent, stirred and dispersed for 40 min, 1.25 mol of phenol was added thereto, stirred at 20°C for 8 h, the solvent was removed by rotary evaporation, washed with water, dried to obtain a silane-containing polyether amine type benzoxazine intermediate.

[0025] (3) 20 g of the silane-containing polyether amine type benzoxazine intermediate, 50 g of epoxy resin were uniformly mixed, warmed to 90°C, preheated for 5 min, 40 g of diaminodimethylmethane was added thereto, stirred uniformly, vacuum degassed, cured in a drying oven, the curing process was 165°C / 1 h, 185°C / 1 h, 215°C / 1 h to obtain an epoxy resin adhesive.

[0026] Example 4 (1) 120 mmol of p-aminophenol, 100 mmol of triethanolamine were dissolved in tetrahydrofuran solvent, stirred and dispersed, 50 mmol of diphenyldichlorosilane was added thereto, warmed to 70°C, refluxed for 40 h, filtered, washed with water, dissolved in petroleum ether, filtered, recrystallized to obtain di(p-aminophenoxy)diphenylsilane.

[0027] (2) 0.5 mol of di(p-aminophenoxy)diphenylsilane, 0.4 mol of polyetheramine, 30% formaldehyde solution were added to toluene solvent, stirred and dispersed for 80 min, 0.8 mol of phenol was added thereto, stirred at 30°C for 6 h, the solvent was removed by rotary evaporation, washed with water, dried to obtain a silane-containing polyether amine type benzoxazine intermediate.

[0028] (3) 25 g of the silane-containing polyether amine type benzoxazine intermediate, 50 g of epoxy resin were mixed uniformly, warmed to 80°C, preheated for 5 min, 50 g of diaminodimethylmethane was added thereto, stirred uniformly, vacuum degassed, cured in a drying oven, the curing process was 160°C / 1 h, 190°C / 1 h, 220°C / 1 h to obtain an epoxy resin adhesive.

[0029] Example 5 (1) 120 mmol of p-aminophenol, 100 mmol of triethanolamine were dissolved in tetrahydrofuran solvent, stirred and dispersed, 50 mmol of diphenyldichlorosilane was added thereto, warmed to 80°C, refluxed for 40 h, filtered, washed with water, dissolved in petroleum ether, filtered, recrystallized to obtain di(p-aminophenoxy)diphenylsilane.

[0030] (2) 0.5 mol of di(p-aminophenoxy)diphenylsilane, 0.38 mol of polyetheramine, 30% formaldehyde solution were added to toluene solvent, stirred and dispersed for 80 min, 1 mol of phenol was added thereto, stirred at 30°C for 8 h, the solvent was removed by rotary evaporation, washed with water, dried to obtain a silane-containing polyether amine type benzoxazine intermediate.

[0031] (3) 30 g of the silane-containing polyether amine type benzoxazine intermediate, 50 g of epoxy resin were mixed uniformly, warmed to 90°C, preheated for 4 min, 50 g of diaminodimethylmethane was added thereto, stirred uniformly, vacuum degassed, cured in a drying oven, the curing process was 160°C / 1 h, 190°C / 1 h, 210°C / 1 h to obtain an epoxy resin adhesive.

[0032] Comparative Example 1 (1) 120 mmol of p-aminophenol and 120 mmol of triethanolamine were dissolved in tetrahydrofuran solvent, stirred and dispersed, 50 mmol of diphenyldichlorosilane was added, heated to 80°C, refluxed for 36 h, filtered, washed with water, then dissolved in petroleum ether, filtered, recrystallized to obtain di(p-aminophenoxy)diphenylsilane.

[0033] (2) 10 g of di(p-aminophenoxy)diphenylsilane and 50 g of epoxy resin were mixed uniformly, heated to 100°C, preheated for 4 min, then 50 g of diaminodimethylmethane was added, stirred uniformly, vacuum degassed, cured in a drying oven, the curing process was 160°C / 1 h, 180°C / 1 h, 220°C / 1 h, to obtain an epoxy resin adhesive.

[0034] Comparative Example 2 (1) 50 g of epoxy resin was mixed uniformly, heated to 100°C, preheated for 4 min, then 50 g of diaminodimethylmethane was added, stirred uniformly, vacuum degassed, cured in a drying oven, the curing process was 160°C / 1 h, 180°C / 1 h, 220°C / 1 h, to obtain an epoxy resin adhesive.

[0035] Thermogravimetric analysis: under nitrogen atmosphere, the heating rate was 10°C / min, the temperature range was 30-800°C. T(0%) was the initial decomposition temperature, T(5%) was the temperature at which 5% of the weight was lost.

[0036]

[0037] As shown in the table, the decomposition temperature of Examples 1-5 is higher than that of Comparative Examples 1-2, therefore, the heat resistance of Examples 1-5 is better than that of Comparative Examples 1-2, because the silane-containing polyether amine type benzoxazine intermediate is contained in Examples 1-5, while Comparative Example 1 only contains di(p-aminophenoxy)diphenylsilane, and Comparative Example 2 does not contain the silane-containing polyether amine type benzoxazine intermediate or di(p-aminophenoxy)diphenylsilane, the heat resistance of Comparative Example 1 is not as good as that of Examples 1-5, and the heat resistance of Comparative Example 2 is the worst, therefore, the silane-containing polyether amine type benzoxazine intermediate prepared in the present application can increase the heat resistance when added to the epoxy resin.

[0038] The above description of disclosed examples enables one skilled in the art to make or use the application. Numerous modifications to these examples will be apparent to those skilled in the art, and the general principles defined herein can be applied to other examples without departing from the spirit or scope of the application. Therefore, the present application is not to be limited to the examples presented herein, but is to accord with the scope of the principles and novel features disclosed herein.

Claims

1. A method for preparing an epoxy resin adhesive, characterized in that, The preparation method is as follows: (1) Dissolve p-aminophenol and triethanolamine in tetrahydrofuran solvent, stir and disperse, then add diphenyldichlorosilane, heat and reflux to react, filter, wash with water, then dissolve in petroleum ether, filter, recrystallize to obtain di(p-aminophenoxy)diphenylsilane. (2) Add bis(p-aminophenoxy)diphenylsilane, polyetheramine, and 30-40% formaldehyde solution to toluene solvent, stir and disperse for 40-80 min, add phenol, stir and react, remove solvent by rotary evaporation, wash with water, and dry to obtain silane-containing polyetheramine type benzoxazine intermediate; (3) Mix the silane-containing polyetheramine benzoxazine intermediate and epoxy resin evenly, heat to 80-100 ℃, preheat for 3-5 min, then add diaminodimethyl ether, stir evenly, degas under vacuum, and cure in a drying oven to obtain epoxy resin adhesive.

2. The method for preparing the epoxy resin adhesive according to claim 1, characterized in that, In step (1), the molar ratio of p-aminophenol, triethanolamine, and diphenyldichlorosilane is 1.8-2.4:2-2.6:

1.

3. The method for preparing the epoxy resin adhesive according to claim 1, characterized in that, In step (1), the reflux reaction time is 30-50 hours and the temperature is 60-80℃.

4. The method for preparing the epoxy resin adhesive according to claim 1, characterized in that, In step (2), the molar ratio of bis(p-aminophenoxy)diphenylsilane, polyetheramine, and phenol is 1:0.6-0.8:1.5-2.

5.

5. The method for preparing the epoxy resin adhesive according to claim 1, characterized in that, The stirring reaction time in step (2) is 5-8 hours and the temperature is 20-35℃.

6. The method for preparing the epoxy resin adhesive according to claim 1, characterized in that, The curing process in step (3) is 160-170℃ / 1h, 180-200℃ / 1h, 210-230℃ / 1h.

7. The method for preparing the epoxy resin adhesive according to claim 1, characterized in that, In step (3), the mass ratio of the silane polyetheramine benzoxazine intermediate, epoxy resin, and 4,4-diaminodiphenyl sulfone is 0.2-0.6:1:0.8-1.2.

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