A method for curing an epoxy resin coating modified with an amino-terminated, ether-containing hyperbranched polyamide

Abstract

The application relates to the technical field of coatings and discloses a curing method of an amino-terminated ether-containing hyperbranched polyamide modified epoxy resin coating, which comprises the following components: 100 parts of a water-based epoxy resin emulsion, 5-20 parts of titanium white powder, 1-2.5 parts of a dispersing agent, 0.05-0.2 parts of a defoaming agent; 50-70 parts of an amino-terminated ether-containing hyperbranched polyamide; the amino-terminated ether-containing hyperbranched polyamide contains active amino groups, so that the amino-terminated ether-containing hyperbranched polyamide can be used as a curing agent to carry out a cross-linking and curing reaction with the epoxy resin; the hyperbranched polyamide has a three-dimensional branched network structure, forms a spatially cross-linked interpenetrating network system with the epoxy resin, and contains flexible ether-containing chain segments and alkyl chain segments, so that a good toughening effect is achieved, the impact resistance and impact strength of the epoxy resin coating and the cast body thereof are improved, and meanwhile, the hardness and tensile strength are maintained.

Description

[0001] The present application is a divisional application of the application with application number 2025100147254, titled "An epoxy resin coating modified by an amino-terminated ether-containing hyperbranched polyamide" and filed on January 6, 2025. TECHNICAL FIELD

[0002] The present application relates to the technical field of coatings, in particular to a curing method of an amino-terminated ether-containing hyperbranched polyamide modified epoxy resin coating. BACKGROUND

[0003] In recent years, the development of new epoxy resin materials by toughening modification of waterborne epoxy resin is a research hotspot. The curing agent of epoxy resin contains curing hydrogen, which can cross-link and cure with epoxy resin, and has many influences on the performance of the cured coating. At present, the curing agents of epoxy resin mainly include amine curing agents, carboxylic acid curing agents, imidazole curing agents, etc. Among them, the polymeric curing agents such as polyamide and polyetheramine have good modification effect on epoxy resin.

[0004] Patent CN113461960B discloses that a hyperbranched epoxy polymer is synthesized from epoxy resin, trimethylolpropane and a catalyst; a single-terminated polyamine is prepared from n-butyl glycidyl ether and a polyamine; and finally, the modified waterborne epoxy curing agent is synthesized from the hyperbranched epoxy polymer, epoxy resin and single-terminated polyamine, which contains a hyperbranched structure, so that the cured coating film has good water resistance, high hardness and impact resistance. Therefore, using hyperbranched polymer as the curing agent of epoxy resin is an effective method to improve the performance of epoxy resin. SUMMARY

[0005] The technical problem solved by the present application is to provide a curing method of an amino-terminated ether-containing hyperbranched polyamide modified epoxy resin coating, which solves the problems of low strength and poor impact resistance of the epoxy resin coating.

[0006] TECHNICAL SOLUTION

[0007] A curing method of an amino-terminated ether-containing hyperbranched polyamide modified epoxy resin coating, comprising the following raw materials by weight fraction: component A: 100 parts of waterborne epoxy resin emulsion, 5-20 parts of titanium white, 1-2.5 parts of dispersing agent, 0.05-0.2 parts of defoaming agent; component B: 50-70 parts of amino-terminated ether-containing hyperbranched polyamide.

[0008] The amino-terminated ether-containing hyperbranched polyamide is prepared according to the following method:

[0009] The structural formula is The ether-containing acrylic ester monomer, ethylenediamine are added into N,N-dimethylformamide, and reacted at a temperature of 110-140 DEG C for 10-18 h, cooled, the solution is poured into methanol for precipitation, after filtration, washed with ethanol, dried at 60-70 DEG C, to obtain the terminal amino ether-containing hyperbranched polyamide;

[0010] The A component and the B component are mixed uniformly, first cured at 60-80 DEG C for 1-2 h, then cured at 100-110 DEG C for 2-4 h, and finally cured at 120-140 DEG C for 2-4 h, to obtain an epoxy resin coating.

[0011] Further, the ratio of the acrylic ester monomer and the ethylenediamine is 1 mol:(4.5-5) mol.

[0012] Further, the ether-containing acrylic ester monomer is prepared as follows:

[0013] S1, methanol is added to methyl acrylate, 1-amino-3,6,9-trioxa-11-undecanol, and nitrogen atmosphere, refluxed at 55-70 DEG C for 24-36 h, cooled, reduced pressure concentration, washed with n-hexane, and dried at 40-50 DEG C, to obtain an intermediate A.

[0014] S2, the intermediate A, hexamethylene diisocyanate, and nitrogen atmosphere are added to any one of tetrahydrofuran, 1,4-dioxane or toluene, and refluxed at a temperature of 70-100 DEG C for 3-5 h, cooled, reduced pressure concentration, washed with n-hexane, and dried at 40-50 DEG C, to obtain the ether-containing acrylic ester monomer.

[0015] Further, the ratio of the methyl acrylate and the 1-amino-3,6,9-trioxa-11-undecanol is (2.4-3.2) mol:1 mol.

[0016] Further, in S3, the molar ratio of the intermediate A and the hexamethylene diisocyanate is (2.2-2.5) mol:1 mol.

[0017] Technical effects are: the terminal amino ether-containing hyperbranched polyamide prepared by the application contains hydrophilic polyether, amide bond and amino group, so that the hyperbranched polyamide has good hydrophilicity and water solubility, and can be well dispersed in the water-based epoxy resin coating matrix.

[0018] Compared with the traditional polyamide curing agent 651, the terminal amino ether-containing hyperbranched polyamide of the application contains active terminal amino groups, which makes it cross-linking curing reaction with epoxy resin as a curing agent. The hyperbranched polyamide has a three-dimensional branched network structure, forms a spatially cross-linked interpenetrating network system with the epoxy resin, and contains flexible ether-containing segments and alkyl segments, which has a good toughening effect, improves the impact resistance and impact strength of the epoxy resin coating and its cast body, while maintaining high hardness and tensile strength. BRIEF DESCRIPTION OF DRAWINGS

[0019] Figure 1 is a preparation reaction route of intermediate A.

[0020] Figure 2 is a preparation reaction route of ether-containing acrylate monomer.

[0021] Figure 3 is a preparation reaction route of terminal amino ether-containing hyperbranched polyamide. DETAILED DESCRIPTION

[0022] Example 1

[0023] 32 mmol of methyl acrylate, 10 mmol of 1-amino-3,6,9-trioxa-11-undecanol, under nitrogen atmosphere, reflux at 55 ℃ for 30 h, cool, concentrate under reduced pressure, wash with n-hexane, dry at 40 ℃, to obtain intermediate A.

[0024] 11 mmol of intermediate A, 5 mmol of hexamethylene diisocyanate, under nitrogen atmosphere, reflux at 70 ℃ for 5 h, cool, concentrate under reduced pressure, wash with n-hexane, dry at 40 ℃, to obtain ether-containing acrylate monomer.

[0025] 5 mmol of ether-containing acrylate monomer, 22.5 mmol of ethylenediamine, are added to 20 mL of N,N-dimethylformamide, and reacted at a temperature of 120 ℃ for 12 h, cool, pour the solution into methanol for precipitation, filter and wash with ethanol, dry at 60 ℃, to obtain terminal amino ether-containing hyperbranched polyamide.

[0026] A component: 100 parts of water-based epoxy resin emulsion, 10 parts of titanium white, 1.5 parts of dispersant LW-110, 0.1 parts of defoamer 902w; B component: 50 parts of terminal amino ether-containing hyperbranched polyamide, are mixed uniformly, first cured at 80 ℃ for 2 h, then cured at 110 ℃ for 3 h, and finally cured at 120 ℃ for 2 h, to obtain an epoxy resin coating.

[0027] Example 2

[0028] To the methanol, 24 mmol of methyl acrylate, 10 mmol of 1-amino-3,6,9-trioxa-11-undecanol, nitrogen atmosphere, 70 ℃ reflux for 24 h, cooling, reduced pressure concentration, n-hexane washing, 45 ℃ drying, to obtain intermediate A.

[0029] To the toluene solvent, 12.5 mmol of intermediate A, 5 mmol of hexamethylene diisocyanate, nitrogen atmosphere, 100 ℃ temperature reflux reaction for 4 h, cooling, reduced pressure concentration, n-hexane washing, 45 ℃ drying, to obtain ether-containing acrylate monomer.

[0030] 5 mmol of ether-containing acrylate monomer, 25 mmol of ethylenediamine was added to 15 mL of N,N-dimethylformamide, reacted at a temperature of 130 ℃ for 12 h, cooled, the solution was poured into methanol for precipitation, washed with ethanol after filtration, and dried at 70 ℃ to obtain an amino-terminated ether-containing hyperbranched polyamide.

[0031] The A component: 100 parts of water-based epoxy resin emulsion, 10 parts of titanium white, 1.5 parts of dispersant LW-110, 0.1 parts of defoamer 902w; B component: 55 parts of amino-terminated ether-containing hyperbranched polyamide, mixed uniformly, first cured at 60 ℃ for 3 h, then cured at 100 ℃ for 4 h, and finally cured at 140 ℃ for 2 h, to obtain an epoxy resin coating.

[0032] Example 3

[0033] To the methanol, 28 mmol of methyl acrylate, 10 mmol of 1-amino-3,6,9-trioxa-11-undecanol, nitrogen atmosphere, 60 ℃ reflux for 24 h, cooling, reduced pressure concentration, n-hexane washing, 40 ℃ drying, to obtain intermediate A.

[0034] To the tetrahydrofuran solvent, 12 mmol of intermediate A, 5 mmol of hexamethylene diisocyanate, nitrogen atmosphere, 70 ℃ temperature reflux reaction for 4 h, cooling, reduced pressure concentration, n-hexane washing, 40 ℃ drying, to obtain ether-containing acrylate monomer.

[0035] 5 mmol of ether-containing acrylate monomer, 23 mmol of ethylenediamine was added to 20 mL of N,N-dimethylformamide, reacted at a temperature of 140 ℃ for 10 h, cooled, the solution was poured into methanol for precipitation, washed with ethanol after filtration, and dried at 70 ℃ to obtain an amino-terminated ether-containing hyperbranched polyamide.

[0036] A component: 100 parts of water-based epoxy resin emulsion, 10 parts of titanium white, 1.5 parts of dispersant LW-110, 0.1 parts of defoamer 902w; B component: 60 parts of amino-terminated ether-containing hyperbranched polyamide, mixed uniformly, first cured at 70°C for 1 h, then cured at 110°C for 2 h, and finally cured at 140°C for 4 h to obtain an epoxy resin coating.

[0037] Example 4

[0038] Add 24 mmol of methyl acrylate, 10 mmol of 1-amino-3,6,9-trioxa-11-undecanol, and nitrogen atmosphere to methanol, reflux at 55°C for 36 h, cool, concentrate under reduced pressure, wash with n-hexane, and dry at 40°C to obtain intermediate A.

[0039] Add 12.5 mmol of intermediate A, 5 mmol of hexamethylene diisocyanate, and nitrogen atmosphere to 1,4-dioxane solvent, reflux at a temperature of 90°C for 4 h, cool, concentrate under reduced pressure, wash with n-hexane, and dry at 40°C to obtain ether-containing acrylate monomer.

[0040] Add 5 mmol of ether-containing acrylate monomer and 22.5 mmol of ethylenediamine to 20 mL of N,N-dimethylformamide, react at a temperature of 120°C for 10 h, cool, pour the solution into methanol for precipitation, wash with ethanol after filtration, and dry at 70°C to obtain amino-terminated ether-containing hyperbranched polyamide.

[0041] A component: 100 parts of water-based epoxy resin emulsion, 10 parts of titanium white, 1.5 parts of dispersant LW-110, 0.1 parts of defoamer 902w; B component: 65 parts of amino-terminated ether-containing hyperbranched polyamide, mixed uniformly, first cured at 60°C for 2 h, then cured at 110°C for 2 h, and finally cured at 130°C for 4 h to obtain an epoxy resin coating.

[0042] Example 5

[0043] Add 24 mmol of methyl acrylate, 10 mmol of 1-amino-3,6,9-trioxa-11-undecanol, and nitrogen atmosphere to methanol, reflux at 60°C for 36 h, cool, concentrate under reduced pressure, wash with n-hexane, and dry at 50°C to obtain intermediate A.

[0044] Add 12 mmol of intermediate A, 5 mmol of hexamethylene diisocyanate, and nitrogen atmosphere to toluene solvent, reflux at a temperature of 100°C for 4 h, cool, concentrate under reduced pressure, wash with n-hexane, and dry at 50°C to obtain ether-containing acrylate monomer.

[0045] 5 mmol ether-containing acrylate monomer, 25 mmol ethylenediamine were added to 15 mL of N, N-dimethylformamide, reacted at a temperature of 140 ℃ for 10 h, cooled, the solution was poured into methanol for precipitation, washed with ethanol after filtration, dried at 60 ℃ to obtain an amino-terminated ether-containing hyperbranched polyamide.

[0046] The A component: 100 parts of water-based epoxy resin emulsion, 10 parts of titanium white, 1.5 parts of dispersant LW-110, 0.1 parts of defoamer 902w; B component: 70 parts of amino-terminated ether-containing hyperbranched polyamide, were mixed uniformly, first cured at 70 ℃ for 2 h, then cured at 100 ℃ for 4 h, and finally cured at 140 ℃ for 3 h to obtain an epoxy resin coating.

[0047] Comparative Example 1

[0048] The A component: 100 parts of water-based epoxy resin emulsion, 10 parts of titanium white, 1.5 parts of dispersant LW-110, 0.1 parts of defoamer 902w; B component: 50 parts of polyamide curing agent 651, were mixed uniformly, first cured at 80 ℃ for 2 h, then cured at 110 ℃ for 3 h, and finally cured at 120 ℃ for 2 h to obtain an epoxy resin coating.

[0049] The amino-terminated ether-containing hyperbranched polyamide was added to distilled water and stirred thoroughly to prepare solutions with different mass fractions. The solutions were left to stand for 48 h, and the state of the solutions was observed.

[0050]

[0051] The amino-terminated ether-containing hyperbranched polyamide has good hydrophilicity and water solubility, and can be uniformly and stably dispersed in an aqueous medium.

[0052] The performance of the epoxy resin coating was tested as follows:

[0053] The pencil hardness was tested according to the standard GB / T 6739-2006.

[0054] The adhesion was tested according to the standard GB / T 9286-2021.

[0055] The impact resistance was tested according to the standard GB / T 1732-2020.

[0056]

[0057] The A component: water-based epoxy resin emulsion, titanium white, dispersant LW-110, defoamer 902w; B component: polyamide curing agent 651, were mixed uniformly, poured into a mold for casting and molding, and then heat-cured. The impact strength and tensile strength were tested according to the methods of GB / T2571-1995 and GB / T2567-2008.

[0058]

[0059] Compared with polyamide curing agent 651, the impact strength of the epoxy resin reaches 21.4-32.0 kJ / m 2 , and the tensile strength reaches 58.6-69.7 MPa.

Claims

1. A curing method for an amino-terminated, ether-containing, hyperbranched polyamide-modified epoxy resin coating, characterized in that, The raw materials include the following parts by weight: Component A: 100 parts waterborne epoxy resin emulsion, 5-20 parts titanium dioxide, 1-2.5 parts dispersant, 0.05-0.2 parts defoamer; Component B: 50-70 parts amino-terminated ether-containing hyperbranched polyamide; The amino-terminated ether-containing hyperbranched polyamide is prepared according to the following method: The structural formula is Ether-containing acrylate monomers and ethylenediamine are added to N,N-dimethylformamide for reaction to obtain amino-terminated ether-containing hyperbranched polyamide; Mix components A and B evenly, first cure at 60-80℃ for 1-2 h, then cure at 100-110℃ for 2-4 h, and finally cure at 120-140℃ for 2-4 h to obtain an epoxy resin coating. The ether-containing acrylate monomer is prepared according to the following method: S1. Add methyl acrylate and 1-amino-3,6,9-triox-11-undecyl alcohol to methanol and reflux at 55-70°C for 24-36 h under a nitrogen atmosphere to obtain intermediate A. S2. Add intermediate A and hexamethylene diisocyanate to the solvent and react under a nitrogen atmosphere to obtain an ether-containing acrylate monomer.

2. The curing method for the amino-terminated ether-containing hyperbranched polyamide-modified epoxy resin coating according to claim 1, characterized in that, The ratio of the ether-containing acrylate monomer to ethylenediamine is 1 mol: (4.5-5) mol.

3. The curing method for the amino-terminated ether-containing hyperbranched polyamide-modified epoxy resin coating according to claim 1, characterized in that, The reaction of ether-containing acrylate monomers with ethylenediamine is carried out at a temperature of 110-140 °C for 10-18 h.

4. The curing method for the amino-terminated ether-containing hyperbranched polyamide-modified epoxy resin coating according to claim 1, characterized in that, The ratio of methyl acrylate to 1-amino-3,6,9-triox-11-undecanol is (2.4-3.2) mol: 1 mol.

5. The curing method for the amino-terminated ether-containing hyperbranched polyamide-modified epoxy resin coating according to claim 1, characterized in that, The solvent in S2 includes tetrahydrofuran, 1,4-dioxane, or toluene.

6. The curing method for the amino-terminated ether-containing hyperbranched polyamide-modified epoxy resin coating according to claim 1, characterized in that, In S2, the molar ratio of intermediate A to hexamethylene diisocyanate is (2.2-2.5) mol: 1 mol.

7. The curing method for the amino-terminated ether-containing hyperbranched polyamide-modified epoxy resin coating according to claim 1, characterized in that, The S2 reaction was refluxed at a temperature of 70-100 °C for 3-5 h.

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