Water-borne epoxy resin and preparation method thereof

Abstract

The invention discloses waterborne epoxy resin and a preparation method thereof, and belongs to the technical field of paints.The preparation method comprises the steps that hydroxyl-terminated polybutadiene and trimellitic anhydride are subjected to a reaction at the temperature of 165-170 DEG C, and an intermediate product M1 is obtained; reacting the intermediate product M1, epoxy resin, ethylene glycol butyl ether, triphenylphosphine and an organic solvent at the temperature of 110-120 DEG C to obtain an intermediate product M2; carrying out a neutralization reaction on the intermediate product M2 and N, N-dimethylethanolamine at the temperature of 85-95 DEG C to obtain an intermediate product M3; and mixing the intermediate product M3 with deionized water to obtain the waterborne epoxy resin. The hydroxyl-terminated polybutadiene with excellent water resistance, acid and alkali resistance, corrosion resistance, insulativity, flexibility and the like is grafted to the epoxy resin through design to prepare the water-borne epoxy resin; the water-based epoxy resin can be applied to water-based self-drying industrial anti-corrosion paint, and has the characteristics of wide universality, room-temperature self-drying, good salt spray resistance, good acid and alkali resistance, good water resistance and the like.

Description

Technical Field

[0001] The invention relates to the technical field of coatings, in particular to a waterborne epoxy resin and a preparation method thereof. Background Art

[0002] After years of development, the development and application of waterborne epoxy resins in China have entered a relatively hot stage. The preparation technology of ordinary waterborne epoxy resins has become increasingly mature, and waterborne epoxy products are also ubiquitous on the market. Ordinary application scenarios are generally available, but for application scenarios that really require salt spray resistance, especially due to the difficulty in substrate treatment and the short activation period of two-component construction, a single-component self-drying or baking drying system must be used. How can the water resistance and salt spray resistance be stably and significantly improved? In response to the needs of this application scenario, there is no suitable solution from market products to publicly available literature, so the current waterborne anti-corrosion industrial coating resins, especially single-component self-drying or baking paint resins, have entered a technical bottleneck period for performance improvement.

[0003] Specifically, existing epoxy resins have at least the following problems:

[0004] 1. The versatility is not wide enough, especially the substrate has a great impact, which is greatly affected by the molecular weight of the epoxy resin and the hydrophilicity / hydrophobicity of the resin chain segment. At present, the molecular weight of domestic water-based epoxy resins is relatively small, and the water resistance of the main resin chain segment is relatively poor.

[0005] 2. The hydrophilic segments of waterborne epoxy resins are mainly provided by non-ionic polyoxyethylene segments, and the hydrophilicity and water absorption of polyoxyethylene segments are very strong, resulting in the salt spray resistance of the coating being unstable or difficult to improve.

[0006] 3. At present, the main method for emulsifying epoxy resin in China is external emulsification, that is, by grafting hydrophilic polyoxyethylene segments with epoxy resin, an emulsifier with one end hydrophilic and the other end lipophilic is formed. This method is used to emulsify epoxy resin. The shortcomings are: the structure of the emulsifier is inconsistent with the hydrophilic and lipophilic properties, resulting in a small molecular weight of the emulsified epoxy resin, a large particle size of the formed water-based epoxy emulsion, and poor storage stability, which also makes it difficult to improve the salt spray resistance of the coating. Summary of the invention

[0007] The object of the present invention is to provide a method for preparing a waterborne epoxy resin to solve the problems raised in the above background technology.

[0008] To achieve the above objectives, the embodiments of the present invention provide the following technical solutions:

[0009] A method for preparing a waterborne epoxy resin comprises the following steps:

[0010] The hydroxy-terminated polybutadiene and trimellitic anhydride are reacted at a temperature of 165°C to 170°C to obtain an intermediate product M1;

[0011] The intermediate product M1, epoxy resin, ethylene glycol butyl ether, triphenylphosphine and an organic solvent are reacted at a temperature of 110-120° C. to obtain an intermediate product M2;

[0012] At a temperature of 85-95° C., the intermediate product M2 is subjected to a neutralization reaction with N,N-dimethylethanolamine to obtain an intermediate product M3;

[0013] The intermediate product M3 is mixed with deionized water to obtain a water-based epoxy resin.

[0014] Preferably, the synthetic raw materials of the water-based epoxy resin include, by weight: 100 parts of hydroxy-terminated polybutadiene, 5-15 parts of trimellitic anhydride, 5-10 parts of organic solvent, 5-65 parts of epoxy resin, 10-30 parts of ethylene glycol monobutyl ether, 0.2-0.4 parts of triphenylphosphine, 5-20 parts of N,N-dimethylethanolamine, and 120-210 parts of deionized water.

[0015] Preferably, the synthetic raw materials of the water-based epoxy resin include, by weight: 100 parts of hydroxy-terminated polybutadiene, 9.6-14.5 parts of trimellitic anhydride, 5-10 parts of organic solvent, 12.5-41.7 parts of epoxy resin, 15-25 parts of ethylene glycol monobutyl ether, 0.2-0.4 parts of triphenylphosphine, 6.6-10 parts of N,N-dimethylethanolamine, and 150-180 parts of deionized water.

[0016] Preferably, the organic solvent is 100# solvent oil.

[0017] Preferably, the epoxy resin is bisphenol A epoxy resin.

[0018] Preferably, the epoxy equivalent of the epoxy resin is 196-3500.

[0019] Another object of an embodiment of the present invention is to provide a water-based epoxy resin prepared by the above preparation method.

[0020] The invention provides a method for preparing a water-based epoxy resin. The method comprises the following steps: grafting terminal hydroxyl polybutadiene having excellent water resistance, acid and alkali resistance, corrosion resistance, insulation, flexibility and the like onto an epoxy resin by design, and creatively reacting the terminal hydroxyl polybutadiene with trimellitic anhydride firstly, and then grafting the reactant with the epoxy resin to obtain the water-based epoxy resin. The water-based epoxy resin can be applied to water-based self-drying (baking varnish) industrial anticorrosive paint, and has the characteristics of wide versatility, room temperature self-drying (medium and high temperature baking varnish), good salt spray resistance, good acid and alkali resistance, good water resistance and the like. DETAILED DESCRIPTION

[0021] The following will be combined with the embodiments of the present invention to clearly and completely describe the technical solutions in the embodiments of the present invention. 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 making creative work are within the scope of protection of the present invention.

[0022] In one embodiment of the present invention, a method for preparing a waterborne epoxy resin is provided, comprising the following steps:

[0023] S1, reacting hydroxy-terminated polybutadiene with trimellitic anhydride at a temperature of 165° C. to 170° C. to obtain an intermediate product M1;

[0024] S2, reacting the intermediate product M1, epoxy resin, ethylene glycol butyl ether, triphenylphosphine and an organic solvent at a temperature of 110-120° C. to obtain an intermediate product M2;

[0025] S3, neutralizing the intermediate product M2 with N,N-dimethylethanolamine at a temperature of 85-95° C. to obtain an intermediate product M3;

[0026] S4, mixing the intermediate product M3 and deionized water to obtain a water-based epoxy resin.

[0027] Specifically, the synthetic route involved in the above preparation method is as follows:

[0028]

[0029]

[0030] In a preferred embodiment of the present invention, the synthetic raw materials of the water-based epoxy resin include, by weight: 100 parts of hydroxy-terminated polybutadiene, 5-15 parts of trimellitic anhydride, 5-10 parts of organic solvent, 5-65 parts of epoxy resin, 10-30 parts of ethylene glycol monobutyl ether, 0.2-0.4 parts of triphenylphosphine, 5-20 parts of N,N-dimethylethanolamine, and 120-210 parts of deionized water.

[0031] In a preferred embodiment of the present invention, the synthetic raw materials of the water-based epoxy resin include, by weight: 100 parts of hydroxy-terminated polybutadiene, 9.6-14.5 parts of trimellitic anhydride, 5-10 parts of organic solvent, 12.5-41.7 parts of epoxy resin, 15-25 parts of ethylene glycol monobutyl ether, 0.2-0.4 parts of triphenylphosphine, 6.6-10 parts of N,N-dimethylethanolamine, and 150-180 parts of deionized water.

[0032] In a preferred embodiment of the present invention, the organic solvent is 100# solvent oil.

[0033] In a preferred embodiment of the present invention, the epoxy resin is bisphenol A type epoxy resin.

[0034] In a preferred embodiment of the present invention, the epoxy equivalent of the epoxy resin is 196-3500.

[0035] It should be noted that the raw materials used above are all commercially available products, for example, trimellitic anhydride is commercially available trimellitic anhydride; epoxy resin is commercially available E51, E20, E12, E06 epoxy resin, etc., but not limited thereto.

[0036] The modified epoxy resin intermediate product M3 prepared by the present invention has the following structural formula. It can also be used as an emulsifier to directly emulsify epoxy resin. As an external emulsifier, it is simple to use.

[0037]

[0038] In addition, since the terminal hydroxyl polybutadiene and epoxy resin segments are introduced into the waterborne epoxy resin molecular segments prepared in the embodiment of the present invention, the resin itself has excellent room temperature self-drying (baking) performance, corrosion resistance, water resistance, and wet adhesion. The technical solution provided in the embodiment of the present invention can adjust the amount of epoxy resin according to specific performance requirements to meet the terminal application requirements.

[0039] The following embodiments are some specific implementation cases of the present invention in practical applications, but are not limited thereto.

[0040] Embodiment 1: This embodiment provides a method for preparing a waterborne epoxy resin, which comprises the following steps:

[0041] S1, 100g of hydroxy-terminated polybutadiene (commercially available specifications: hydroxyl value of 0.755mmol / g) and 14.5g of trimellitic anhydride were mixed and reacted at a temperature of 165°C-170°C for 1 hour. After the acid value was tested to be about 74±1mgKOH / g and qualified, the temperature was lowered to 110°C to obtain an intermediate product M1;

[0042] S2, continue to add 7.4g of E51 epoxy resin, 15g of ethylene glycol butyl ether, 0.3g of triphenylphosphine, and 5g of 100# solvent oil to the above system, mix with the intermediate product M1, and keep warm at a temperature of 110-120°C for 2 hours. After the acid value is tested to be 44.5±1mgKOH / g, the intermediate product M2 is obtained;

[0043] S3, cooling the above system to 85-95°C, then adding 10 g of N,N-dimethylethanolamine and conducting a neutralization reaction with the intermediate product M2 for 20 minutes to obtain an intermediate product M3;

[0044] S4. Under high-speed dispersion, slowly add 150 g of deionized water and mix with the intermediate product M3 to obtain a water-based epoxy resin.

[0045] Embodiment 2: This embodiment provides a method for preparing a waterborne epoxy resin, which comprises the following steps:

[0046] S1, 100g of hydroxy-terminated polybutadiene (commercially available specifications: hydroxyl value of 0.755mmol / g) and 14.5g of trimellitic anhydride were mixed and reacted at a temperature of 165°C-170°C for 1 hour. After the acid value was tested to be about 74±1mgKOH / g and qualified, the temperature was lowered to 110°C to obtain an intermediate product M1;

[0047] S2, continue to add 18.9g of E20 epoxy resin, 20g of ethylene glycol butyl ether, 0.3g of triphenylphosphine, 5g of 100# solvent oil to the above system, mix with the intermediate product M1, and keep warm at a temperature of 110-120°C for 2 hours. After the acid value is tested to be 40±1mgKOH / g and qualified, the intermediate product M2 is obtained;

[0048] S3, cooling the above system to 90° C., then adding 10 g of N,N-dimethylethanolamine and conducting a neutralization reaction with the intermediate product M2 for 20 minutes to obtain an intermediate product M3;

[0049] S4. Under high-speed dispersion, slowly add 160 g of deionized water and mix with the intermediate product M3 to obtain a water-based epoxy resin.

[0050] Embodiment 3: This embodiment provides a method for preparing a waterborne epoxy resin, which comprises the following steps:

[0051] S1, 100g of hydroxy-terminated polybutadiene (commercially available specifications: hydroxyl value of 0.755mmol / g) and 14.5g of trimellitic anhydride were mixed and reacted at a temperature of 165°C-170°C for 1 hour. After the acid value was tested to be about 74±1mgKOH / g and qualified, the temperature was lowered to 110°C to obtain an intermediate product M1;

[0052] S2, continue to add 31.5g of E12 epoxy resin, 25g of ethylene glycol butyl ether, 0.3g of triphenylphosphine, 10g of 100# solvent oil to the above system, mix with the intermediate product M1, and keep warm at a temperature of 110-120°C for 2 hours. After the acid value is tested to be 35±1mgKOH / g, the intermediate product M2 is obtained;

[0053] S3, cooling the above system to 90° C., then adding 10 g of N,N-dimethylethanolamine and conducting a neutralization reaction with the intermediate product M2 for 20 minutes to obtain an intermediate product M3;

[0054] S4. Under high-speed dispersion, slowly add 175 g of deionized water and mix with the intermediate product M3 to obtain a water-based epoxy resin.

[0055] Embodiment 4: This embodiment provides a method for preparing a waterborne epoxy resin, which comprises the following steps:

[0056] S1, 100g of hydroxy-terminated polybutadiene (commercially available specifications: hydroxyl value of 0.755mmol / g) and 14.5g of trimellitic anhydride were mixed and reacted at a temperature of 165°C-170°C for 1 hour. After the acid value was tested to be about 74±1mgKOH / g and qualified, the temperature was lowered to 110°C to obtain an intermediate product M1;

[0057] S2, continue to add 62.9g of E06 epoxy resin, 30g of ethylene glycol butyl ether, 0.3g of triphenylphosphine, 10g of 100# solvent oil to the above system, mix with the intermediate product M1, and keep warm at a temperature of 110-120°C for 2 hours. After the acid value is tested to be 30±1mgKOH / g and qualified, the intermediate product M2 is obtained;

[0058] S3, cooling the above system to 90° C., then adding 10 g of N,N-dimethylethanolamine and conducting a neutralization reaction with the intermediate product M2 for 20 minutes to obtain an intermediate product M3;

[0059] S4. Under high-speed dispersion, slowly add 210 g of deionized water and mix with the intermediate product M3 to obtain a water-based epoxy resin.

[0060] Embodiment 5: This embodiment provides a method for preparing a waterborne epoxy resin, which comprises the following steps:

[0061] S1, 100g of hydroxy-terminated polybutadiene (commercially available specifications: hydroxyl value of 0.5mmol / g) and 9.6g of trimellitic anhydride were mixed and reacted at a temperature of 165°C-170°C for 1 hour. After the acid value was tested to be about 51±1mgKOH / g and qualified, the temperature was lowered to 110°C to obtain an intermediate product M1;

[0062] S2, continue to add 4.9g of E51 epoxy resin, 15g of ethylene glycol butyl ether, 0.3g of triphenylphosphine, and 5g of 100# solvent oil to the above system, mix with the intermediate product M1, and keep warm at a temperature of 110-120°C for 2 hours. After the acid value is tested to be 31±1mgKOH / g and qualified, the intermediate product M2 is obtained;

[0063] S3, cooling the above system to 90° C., then adding 6.6 g of N,N-dimethylethanolamine to the intermediate product M2 for a neutralization reaction for 20 minutes to obtain an intermediate product M3;

[0064] S4. Under high-speed dispersion, slowly add 150 g of deionized water and mix with the intermediate product M3 to obtain a water-based epoxy resin.

[0065] Embodiment 6: This embodiment provides a method for preparing a waterborne epoxy resin, which comprises the following steps:

[0066] S1, 100g of hydroxy-terminated polybutadiene (commercially available specifications: hydroxyl value of 0.5mmol / g) and 9.6g of trimellitic anhydride were mixed and reacted at a temperature of 165°C-170°C for 1 hour. After the acid value was tested to be about 51±1mgKOH / g and qualified, the temperature was lowered to 110°C to obtain an intermediate product M1;

[0067] S2, continue to add 12.5g of E20 epoxy resin, 20g of ethylene glycol butyl ether, 0.3g of triphenylphosphine, and 5g of 100# solvent oil to the above system, mix with the intermediate product M1, and keep warm at a temperature of 110-120°C for 2 hours. After the acid value is tested to be 29±1mgKOH / g, the intermediate product M2 is obtained;

[0068] S3, cooling the above system to 90° C., then adding 6.6 g of N,N-dimethylethanolamine to the intermediate product M2 for a neutralization reaction for 20 minutes to obtain an intermediate product M3;

[0069] S4. Under high-speed dispersion, slowly add 150 g of deionized water and mix with the intermediate product M3 to obtain a water-based epoxy resin.

[0070] Embodiment 7: This embodiment provides a method for preparing a waterborne epoxy resin, which comprises the following steps:

[0071] S1, 100g of hydroxy-terminated polybutadiene (commercially available specifications: hydroxyl value of 0.5mmol / g) and 9.6g of trimellitic anhydride were mixed and reacted at a temperature of 165°C-170°C for 1 hour. After the acid value was tested to be about 51±1mgKOH / g and qualified, the temperature was lowered to 110°C to obtain an intermediate product M1;

[0072] S2, continue to add 20.8g of E12 epoxy resin, 25g of ethylene glycol butyl ether, 0.3g of triphenylphosphine, and 10g of 100# solvent oil to the above system, mix with the intermediate product M1, and keep warm at a temperature of 110-120°C for 2 hours. After the acid value is tested to be 25±1mgKOH / g, the intermediate product M2 is obtained;

[0073] S3, cooling the above system to 90° C., then adding 6.6 g of N,N-dimethylethanolamine to the intermediate product M2 for a neutralization reaction for 20 minutes to obtain an intermediate product M3;

[0074] S4. Under high-speed dispersion, slowly add 155 g of deionized water and mix with the intermediate product M3 to obtain a water-based epoxy resin.

[0075] Embodiment 8: This embodiment provides a method for preparing a waterborne epoxy resin, which comprises the following steps:

[0076] S1, 100g of hydroxy-terminated polybutadiene (commercially available specifications: hydroxyl value of 0.755mmol / g) and 14.5g of trimellitic anhydride were mixed and reacted at a temperature of 165°C-170°C for 1 hour. After the acid value was tested to be about 74±1mgKOH / g and qualified, the temperature was lowered to 110°C to obtain an intermediate product M1;

[0077] S2, continue to add 41.7g of E06 epoxy resin, 30g of ethylene glycol butyl ether, 0.3g of triphenylphosphine, 10g of 100# solvent oil to the above system, mix with the intermediate product M1, and keep warm at a temperature of 110-120°C for 2 hours. After the acid value is tested to be 22±1mgKOH / g, the intermediate product M2 is obtained;

[0078] S3, cooling the above system to 90° C., then adding 6.6 g of N,N-dimethylethanolamine to the intermediate product M2 for a neutralization reaction for 20 minutes to obtain an intermediate product M3;

[0079] S4. Under high-speed dispersion, slowly add 180 g of deionized water and mix with the intermediate product M3 to obtain a water-based epoxy resin.

[0080] Comparative Example 1: This comparative example provides a water-based epoxy resin, which is prepared by the preparation method disclosed in the patent application number 202011129671.X.

[0081] Comparative Example 2: This comparative example provides a water-based epoxy resin, which is prepared by the preparation method disclosed in patent application number 201910827751.3.

[0082] The performance of the waterborne epoxy resins prepared in the above Examples 1-8 and Comparative Examples 1-2 was tested, and the specific test results are shown in Table 1 below:

[0083] Table 1

[0084]

[0085] From the comparison results in the above table, it can be seen that the water-based epoxy resins prepared in Examples 3 and 4 of the present invention can achieve self-drying at room temperature and rapid baking at low temperature, and the products have good dry and wet adhesion. Compared with the comparative example, the anti-corrosion performance of the products is obviously more versatile in substrate treatment and has more stable performance.

[0086] Based on the above-mentioned ideal embodiments of the present invention, the relevant staff can make various changes and modifications without departing from the technical concept of the present invention through the above-mentioned description. The technical scope of the present invention is not limited to the contents of the specification.

Claims

1. A method for preparing a waterborne epoxy resin, characterized in that: The following steps are involved: The hydroxy-terminated polybutadiene and trimellitic anhydride are reacted at a temperature of 165°C to 170°C to obtain an intermediate product M1; The intermediate product M1, epoxy resin, ethylene glycol butyl ether, triphenylphosphine and an organic solvent are reacted at a temperature of 110-120° C. to obtain an intermediate product M2; At a temperature of 85-95° C., the intermediate product M2 is subjected to a neutralization reaction with N,N-dimethylethanolamine to obtain an intermediate product M3; The intermediate product M3 is mixed with deionized water to obtain a water-based epoxy resin.

2. The method for preparing a waterborne epoxy resin according to claim 1, characterized in that: The synthetic raw materials of the waterborne epoxy resin include, by weight: 100 parts of hydroxy-terminated polybutadiene, 5-15 parts of trimellitic anhydride, 5-10 parts of organic solvent, 5-65 parts of epoxy resin, 10-30 parts of ethylene glycol monobutyl ether, 0.2-0.4 parts of triphenylphosphine, 5-20 parts of N,N-dimethylethanolamine, and 120-210 parts of deionized water.

3. The method for preparing a waterborne epoxy resin according to claim 2, characterized in that: The synthetic raw materials of the waterborne epoxy resin include, by weight: 100 parts of hydroxy-terminated polybutadiene, 9.6-14.5 parts of trimellitic anhydride, 5-10 parts of organic solvent, 12.5-41.7 parts of epoxy resin, 15-25 parts of ethylene glycol monobutyl ether, 0.2-0.4 parts of triphenylphosphine, 6.6-10 parts of N,N-dimethylethanolamine, and 150-180 parts of deionized water.

4. The method for preparing a waterborne epoxy resin according to any one of claims 1 to 3, characterized in that: The organic solvent is 100# solvent oil.

5. The method for preparing a waterborne epoxy resin according to any one of claims 1 to 3, characterized in that: The epoxy resin is bisphenol A type epoxy resin.

6. The method for preparing a waterborne epoxy resin according to claim 5, characterized in that: The epoxy equivalent of the epoxy resin is 196-3500.

7. A water-based epoxy resin prepared by the preparation method according to any one of claims 1 to 6.

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