阅读说明：本技术 一种水性环氧树脂固化剂及其制备方法 (Water-based epoxy resin curing agent and preparation method thereof ) 是由 张英强 赵鹏 李烨 于 2021-01-11 设计创作，主要内容包括：本发明公开了一种水性环氧树脂用固化剂,其特征在于,为含有氨基甲酸酯单元和脲单元的醇胺类固化剂。制备方法为：二异氰酸酯与聚乙二醇单甲醚反应,得到含有一端含异氰酸酯基,一端含甲氧基的氨基甲酸酯的反应产物Ⅰ,与脂肪族多元胺反应,得到含有一端含有甲氧基,一端含伯胺基的脲类的反应产物Ⅱ,与单官能度氟改性环氧活性稀释剂反应,得到含有醇胺产物的水性环氧树脂用固化剂。本发明的水性环氧树脂固化剂的制备方法,其制备路线短、反应温和,粘度小,不需要压力反应设备,因此具有制备过程简单、操作方便、反应条件温和,适于工业化生产。本发明具有能够有效改善水性环氧树脂固化膜耐水效果以及提升膜固化膜表面性能的特点。(The invention discloses a curing agent for waterborne epoxy resin, which is characterized by being an alcamine curing agent containing a carbamate unit and a urea unit. The preparation method comprises the following steps: reacting diisocyanate with polyethylene glycol monomethyl ether to obtain a reaction product I containing carbamate with one end containing isocyanate group and one end containing methoxyl group, reacting with aliphatic polyamine to obtain a reaction product II containing urea with one end containing methoxyl group and one end containing primary amine group, and reacting with a monofunctional fluorine modified epoxy active diluent to obtain the curing agent for the waterborne epoxy resin containing alcohol amine product. The preparation method of the waterborne epoxy resin curing agent has the advantages of short preparation route, mild reaction, low viscosity and no need of pressure reaction equipment, so the preparation method has the advantages of simple preparation process, convenient operation and mild reaction conditions, and is suitable for industrial production. The invention has the characteristics of effectively improving the water-resistant effect of the water-based epoxy resin cured film and improving the surface performance of the film cured film.)

1. The curing agent for the water-based epoxy resin is characterized by being an alcohol amine curing agent containing a carbamate unit and a urea unit, and the raw materials of the curing agent comprise diisocyanate, polyethylene glycol monomethyl ether, aliphatic polyamine and a monofunctional fluorine modified epoxy active diluent, wherein the structural formula of the polyethylene glycol monomethyl ether is CH₃O(C₂H₄O)_nH, n is more than or equal to 1 and less than or equal to 100; the aliphatic polyamine contains more than two primary amine groups; the monofunctional fluorine-modified epoxy reactive diluent is an epoxy compound which is modified by fluorine groups and contains an epoxy group.

2. The curing agent for the water-based epoxy resin as claimed in claim 1, wherein the raw materials comprise 10-100 parts by weight of diisocyanate, 30-330 parts by weight of polyethylene glycol monomethyl ether, 10-100 parts by weight of aliphatic polyamine, 45-500 parts by weight of monofunctional fluorine-modified epoxy reactive diluent and 100-1000 parts by weight of deionized water.

3. The curing agent for water-based epoxy resin according to claim 1, wherein the diisocyanate is any one or more of toluene diisocyanate, isophorone diisocyanate, diphenylmethane diisocyanate, dicyclohexylmethane diisocyanate and lysine diisocyanate.

4. The curing agent for water-based epoxy resins according to claim 1, wherein the molecular weight M of the polyethylene glycol monomethyl ether is in the range of 200. ltoreq. M.ltoreq.5500.

5. The curing agent for waterborne epoxy resin according to claim 1, wherein the monofunctional fluorine-modified epoxy reactive diluent comprises the following components in parts by weight:

the preparation method of the monofunctional fluorine modified epoxy reactive diluent comprises the following steps: reacting isophorone diisocyanate with hexafluoroisopropanol to obtain an intermediate product A of carbamate of which one end contains an isocyanate group and the other end contains a C-F bond; and reacting the residual isocyanate group contained in the intermediate product A with epoxy propanol to obtain a reaction product B with one end of the molecule containing an epoxy group and one end containing a C-F bond.

6. The curing agent for water-based epoxy resin according to claim 1, wherein the aliphatic polyamine has a structural formula of H₂N-R-NH₂Wherein R is ((CH)₂)₂NH)_n(CH₂)₂And n is 1, 2, 3 or 4.

7. The curing agent for water-based epoxy resin according to claim 6, wherein the aliphatic polyamine is at least one of diethylenetriamine, triethylenetetramine and tetraethylenepentamine.

8. The method for preparing the curing agent for water-based epoxy resin according to any one of claims 1 to 7, comprising the steps of:

step 1): reacting diisocyanate with polyethylene glycol monomethyl ether to obtain a reaction product I containing carbamate with one end containing isocyanate group and one end containing methoxyl group;

step 2): reacting the residual isocyanate group contained in the reaction product I with aliphatic polyamine to obtain a reaction product II of urea with one end containing methoxyl and one end containing primary amino;

step 3): and reacting the primary amine group contained in the reaction product II with a monofunctional fluorine modified epoxy active diluent to obtain the aqueous epoxy resin curing agent containing the alcohol amine product.

9. The method for preparing the curing agent for water-based epoxy resin according to claim 8, wherein the reaction temperature in the step 1) is 30 to 50 ℃; the reaction temperature in the step 2) and the step 3) is 50-80 ℃; and 3) before the reaction product II reacts with the monofunctional fluorine modified epoxy reactive diluent to obtain the curing agent for the modified waterborne epoxy resin, adding deionized water.

10. The method for preparing the curing agent for the water-based epoxy resin according to claim 8, wherein the molar ratio of the methoxypolyethylene glycol to the diisocyanate in the step 1) is 1 (1-2); in the step 2), the molar ratio of the isocyanate group of the reaction product I to the primary amino group of the aliphatic polyamine is 1 (1-2); in the step 3), the molar ratio of the primary amine group of the reaction product II to the epoxy group of the monofunctional fluorine modified epoxy reactive diluent is 1 (1-2).

Technical Field

The invention relates to a waterborne epoxy resin curing agent, belonging to the technical field of high polymer materials.

Background

The epoxy resin contains two or more epoxy groups in a molecular structure, and is widely applied to two-component epoxy coating due to excellent properties of substrate adhesion, heat resistance, corrosion resistance and the like. The solvent type epoxy coating contains organic volatile matters such as formaldehyde, toluene and the like, which seriously endanger the ecological environment and human health, so the development of the water-based epoxy coating which replaces organic solvent with water is a necessary trend in the development of the current coating industry. The waterborne epoxy curing agent is an important component of the waterborne epoxy coating and plays a decisive role in the final performance of the coating.

The waterborne epoxy curing agents in the market at present are mainly divided into two categories, namely ionic waterborne epoxy curing agents and nonionic waterborne epoxy curing agents. Wherein, the synthesis of the nonionic waterborne epoxy curing agent is reported, and Chinese patent CN104479110A discloses a preparation method of the nonionic waterborne epoxy curing agent, which comprises the following steps: adding 10-30 parts of diisocyanate, 10-45 parts of epoxy resin and 0.6-6 parts of catalyst into a reaction kettle according to the weight part ratio, heating for reaction, then adding 40-120 parts of polyether polyol, heating for reaction, adding 20-80 parts of amine for reaction, finally adding 5-25 parts of monoepoxy compound for reaction, and dispersing with 50-300 parts of water to obtain the synthesis and performance of the nonionic self-emulsifying epoxy emulsion. The polyether chain segment, the epoxy resin chain segment and the polyurethane structure are introduced into the structure of the waterborne curing agent, so that the waterborne epoxy curing agent with better flexibility is prepared. However, in such a method, a hydrophilic polyether structure is introduced into the main chain of the curing agent, and although the problem of water dispersibility is solved, the water resistance of a cured product is greatly affected, and the water resistance and the surface performance of a coating film are greatly affected.

Disclosure of Invention

The technical problem to be solved by the invention is as follows: the defects of poor water resistance and poor surface performance exist in the preparation of the water-based epoxy curing agent in the prior art, the water-based epoxy curing agent emulsion which is easy to prepare, good in surface performance and excellent in water resistance is provided, and the convenient water-based epoxy resin curing agent and the preparation method thereof are provided.

In order to solve the technical problems, the invention provides a curing agent for water-based epoxy resin, which is characterized in that the curing agent is an alcamine curing agent containing a carbamate unit and a urea unit, and the raw materials of the curing agent comprise diisocyanate, polyethylene glycol monomethyl ether, aliphatic polyamine and a monofunctional fluorine modified epoxy active diluent, wherein the structural formula of the polyethylene glycol monomethyl ether is CH₃O(C₂H₄O)_nH, n is more than or equal to 1 and less than or equal to 100; the aliphatic polyamine contains more than two primary amine groups; the monofunctional fluorine-modified epoxyThe reactive diluent is an epoxy compound which is modified by fluorine groups and contains an epoxy group; wherein the carbamate unit is a unit obtained by reacting diisocyanate and polyethylene glycol monomethyl ether, one end of the carbamate unit contains a methoxyl group, and the other end of the carbamate unit is connected with a urea group of a urea unit containing alcohol amine; one end of the urea unit is an alkyl-substituted alcohol amine group, and the aliphatic polyamine and the monofunctional fluorine-modified epoxy reactive diluent are respectively used as raw materials for providing amino and hydroxyl of the alcohol amine group.

Preferably, the raw materials comprise, by weight, 10-100 parts of diisocyanate, 30-330 parts of polyethylene glycol monomethyl ether, 10-100 parts of aliphatic polyamine, 45-500 parts of monofunctional fluorine modified epoxy reactive diluent and 100-1000 parts of deionized water.

Preferably, the diisocyanate is any one or more of toluene diisocyanate, isophorone diisocyanate, diphenylmethane diisocyanate, dicyclohexylmethane diisocyanate and lysine diisocyanate, and is preferably isophorone diisocyanate.

Preferably, the molecular weight M of the polyethylene glycol monomethyl ether is in the range of 200. ltoreq. M.ltoreq.5500, preferably 750. ltoreq. M.ltoreq.1200.

Preferably, the monofunctional fluorine-modified epoxy reactive diluent comprises the following components in parts by weight:

the preparation method of the monofunctional fluorine modified epoxy reactive diluent comprises the following steps: reacting isophorone diisocyanate with hexafluoroisopropanol to obtain an intermediate product A of carbamate of which one end contains an isocyanate group and the other end contains a C-F bond; and reacting the residual isocyanate group contained in the intermediate product A with epoxy propanol to obtain a reaction product B with one end of the molecule containing an epoxy group and one end containing a C-F bond. The reaction process is as follows:

preferably, the structural formula of the aliphatic polyamine is H₂N-R-NH₂Wherein R is ((CH)₂)₂NH)_n(CH₂)₂And n is 1, 2, 3 or 4.

More preferably, the aliphatic polyamine is at least one of diethylenetriamine, triethylene tetramine and tetraethylene pentamine, and is preferably tetraethylene pentamine.

The invention also provides a preparation method of the curing agent for the waterborne epoxy resin, which is characterized by comprising the following steps:

step 1): reacting diisocyanate with polyethylene glycol monomethyl ether to obtain a reaction product I containing carbamate with one end containing isocyanate group and one end containing methoxyl group;

step 2): reacting the residual isocyanate group contained in the reaction product I with aliphatic polyamine to obtain a reaction product II of urea with one end containing methoxyl and one end containing primary amino;

step 3): and reacting the primary amine group contained in the reaction product II with a monofunctional fluorine modified epoxy active diluent to obtain the aqueous epoxy resin curing agent containing the alcohol amine product.

When the diisocyanate is isophorone diisocyanate, the reaction equation is as follows:

wherein R is_fThe portion remaining after removal of the epoxy group for reaction product B.

Preferably, the temperature of the reaction in step 1) is 30-50 ℃, preferably 30-40 ℃; the temperature of the reaction in the step 2) and the step 3) is 50-80 ℃, preferably 50-70 ℃.

Preferably, the molar ratio of the polyethylene glycol monomethyl ether to the diisocyanate in the step 1) is 1 (1-2), preferably 1 (1-1.5), and more preferably 1 (1-1.3); further 1 (1-1.2); in the step 2), the molar ratio of the isocyanate group of the reaction product I to the primary amine group of the aliphatic polyamine is 1 (1-2), preferably 1 (1-1.5), more preferably 1 (1-1.3), and further 1 (1-1.2); in the step 3), the molar ratio of the primary amine group of the reaction product II to the epoxy group of the monofunctional fluorine-modified epoxy reactive diluent is 1 (1-2), preferably 1 (1-1.5), more preferably 1 (1-1.3), and further 1 (1-1.2).

Preferably, the method further comprises a process of adding deionized water before the curing agent for the modified waterborne epoxy resin is obtained after the reaction product II in the step 3) reacts with the monofunctional fluorine modified epoxy reactive diluent.

Firstly, isophorone diisocyanate and hexafluoroisopropanol which are accurately proportioned are adopted, hexafluoroisopropanol is reacted with one isocyanate of isophorone diisocyanate by utilizing hydroxyl, is connected into an isophorone diisocyanate structure, and then is accurately reacted with epoxy propanol to prepare the monofunctional fluorine modified epoxy reactive diluent. The method comprises the following steps of adopting isophorone diisocyanate and polyethylene glycol monomethyl ether which are accurately matched, enabling water dispersible polyethylene glycol monomethyl ether to react with one isocyanate of isophorone diisocyanate by utilizing hydroxyl, connecting the water dispersible polyethylene glycol monomethyl ether into an isophorone diisocyanate structure, then adding aliphatic polyamine according to the accurate stoichiometric ratio, and sealing about 50% of primary amine hydrogen, wherein one end of the compound B contains methoxyl and the other end of the compound B contains primary amine; then, the monofunctional fluorine modified epoxy active diluent is subjected to stoichiometric reaction with the primary amino group of the compound B and is added to achieve proper hydrophilic-lipophilic balance, and the sealant type water-based epoxy curing agent is generated. The curing agent for the water-based epoxy resin can be widely applied to the technical field of coating protection of airplanes, ships, buildings, traffic and various mechanical equipment, and can meet the use requirement of the water-based epoxy resin.

Compared with the prior art, the invention has the beneficial effects that:

1. the water-based epoxy resin curing agent has better hydrophilic and oleophilic properties, better dispersion and emulsification properties, higher storage stability and film forming property, a certain number of C-F bonds in a curing film, and better surface property and water resistance of the curing film.

2. The preparation method of the invention has mild reaction, does not need pressure reaction equipment, has simple preparation process and convenient operation, is suitable for industrial production, and can be widely used for preparing protective coatings of airplanes, ships, buildings, traffic and various mechanical equipment.

Detailed Description

In order to make the invention more comprehensible, preferred embodiments are described in detail below.

The preparation method of the monofunctional fluorine modified epoxy reactive diluent comprises the following steps:

the monofunctional fluorine modified epoxy reactive diluent is characterized by comprising the following components in parts by weight:

a stirrer and a thermometer are arranged on a 250mL four-mouth flask and connected with the stirrer; 50g of isophorone diisocyanate is put into a flask, 40g of hexafluoroisopropanol is poured into a constant pressure funnel, and 0.02g of catalyst is dripped into a four-neck flask; introduction of N₂Controlling the reaction temperature to be 35 ℃, uniformly dripping hexafluoroisopropanol into IPDI at the speed of 1 drop/second, and reacting for 2 hours after dripping is finished; weighing 20g of epoxy propanol, pouring into a 250mL four-neck flask, and adjusting the temperature of a water bath to 50 ℃; and finishing the reaction after 2 hours to obtain the monofunctional fluorine modified epoxy reactive diluent.

Examples 1-3 all employed the monofunctional fluorine-modified epoxy reactive diluent prepared as described above.

The water-based epoxy resin curing agent comprises the following preparation raw materials in parts by weight:

the aliphatic polyamine is one or a mixture of more than two of diethylenetriamine, triethylene tetramine and tetraethylene pentamine;

the reagents and instruments used in the examples are shown in Table 1.

TABLE 1 reagents and apparatus used in the examples

Reagent/instrument	Purity/type	Manufacturer of the product
			Isophorone diisocyanate	CP	Wuhan Fuxin Yuanjin Tech Co Ltd
Polyethylene glycol monomethyl ether MPEG1000	CP/MPEG1000	Jiangsu Hai'an petrochemical plant
			N-butyl glycidyl ether	CP	SHANGHAI ALADDIN BIOCHEMICAL TECHNOLOGY Co.,Ltd.
Hexafluoroisopropanol	CP	SHANGHAI ALADDIN BIOCHEMICAL TECHNOLOGY Co.,Ltd.
			C12-14Alkyl glycidyl ethers of	CP	SHANGHAI ALADDIN BIOCHEMICAL TECHNOLOGY Co.,Ltd.
Tetraethylenepentamine	Industrial grade	Zhejiang Fenghua practice Co., Ltd
			Triethylene tetramine	Industrial grade	Zhejiang Fenghua practice Co., Ltd
Epoxypropanol	CP	SHANGHAI TITAN TECHNOLOGY Co.,Ltd.
			Contact angle measuring instrument	SDC-200S type	Dongguan Cheng Ding precision instruments Co Ltd

Example 1

A preparation method of a water-based epoxy resin curing agent comprises the following steps:

step 1: adding 10g of isophorone diisocyanate (IPDI) into a 500mL four-neck flask with a thermometer and a condenser, heating to 30 ℃ under the protection of nitrogen, and starting a stirrer; slowly adding 45.04g of polyethylene glycol monomethyl ether MPEG1000 without water dropwise in 3 times, and reacting for 1 hour; obtaining a reaction product I of carbamate with one end containing isocyanate group and one end containing methoxyl group;

step 2: adding 8.50g of tetraethylenepentamine into a flask, slowly dropwise adding the reaction product I obtained in the step 1 into the flask, slowly raising the temperature to 50 ℃ after dropwise adding, and continuously reacting for 2 hours to obtain a reaction product II of urea with one end containing methoxy and one end containing primary amino;

and step 3: adding 34.62g of monofunctional fluorine modified epoxy reactive diluent into a flask, slowly dropwise adding the reaction product II into the flask, continuously reacting for 1h at 50 ℃, finally slowly adding 1000g of deionized water into the flask, and uniformly stirring and mixing to obtain the aqueous epoxy curing agent A1 containing the alcohol amine product.

Weighing the epoxy resin according to a certain proportion, and then adding the curing agent with the same functionality ratio. Melting and mixing at a certain temperature, and injecting into an aluminum foil mold; and then placing the mixture into a curing furnace, curing the mixture at a specified temperature, stopping heating, and naturally cooling the mixture to room temperature to obtain a cured product sample.

The contact angle of the obtained epoxy resin condensate with water is measured by adopting an OCA40 Micro surface contact angle tester of Germany Dataphysics company, 5 different smooth places on the surface of a sample are selected for measurement, the average value is taken, and the contact angle of the condensate with water reaches 98 degrees.

The water resistance of the epoxy resin cured film obtained in the above was measured according to GB/T1733-1993 paint film water resistance test method, and the results showed that no phenomena such as light loss, foaming and whitening occurred within 308 hours.

Example 2

A preparation method of a water-based epoxy resin curing agent comprises the following steps:

step 1: adding 20g of isophorone diisocyanate (IPDI) into a 1000mL four-neck flask with a thermometer and a condenser, heating to 30 ℃ under the protection of nitrogen, and starting a stirrer; slowly adding 60g of the polyethylene glycol monomethyl ether MPEG1000 without water dropwise in 3 times, and reacting for 1 hour; obtaining a reaction product I of carbamate with one end containing isocyanate group and one end containing methoxyl group;

step 2: adding 20g of tetraethylenepentamine into a flask, slowly dropwise adding the reaction product I obtained in the step 1 into the flask, slowly raising the temperature to 50 ℃ after the dropwise adding is finished, and continuously reacting for 2 hours to obtain a urea reaction product II containing a methoxyl group at one end and a primary amino group at one end;

and step 3: adding 70g of monofunctional fluorine modified epoxy reactive diluent into a flask, slowly dropwise adding the reaction product II into the flask, continuously reacting for 1h at 50 ℃, finally slowly adding 200g of deionized water into the flask, and uniformly stirring and mixing to obtain the waterborne epoxy curing agent A2 containing the alcohol amine product.

Weighing the epoxy resin according to a certain proportion, and then adding the curing agent with the same functionality ratio. Melting and mixing at a certain temperature, and injecting into an aluminum foil mold; and then placing the mixture into a curing furnace, curing the mixture at a specified temperature, stopping heating, and naturally cooling the mixture to room temperature to obtain a cured product sample.

The contact angle of the obtained epoxy resin condensate with water is measured by adopting an OCA40 Micro surface contact angle tester of Germany Dataphysics company, 5 different smooth places on the surface of a sample are selected for measurement, the average value is taken, and the contact angle of the condensate with water reaches 95 degrees.

The water resistance of the epoxy resin cured film obtained in the above was measured according to GB/T1733-1993 paint film water resistance test method, and the result showed that no phenomena such as light loss, foaming and whitening occurred within 296 hours.

Example 3

A preparation method of a water-based epoxy resin curing agent comprises the following steps:

step 1: adding 100g of isophorone diisocyanate (IPDI) into a 2500mL four-neck flask with a thermometer and a condenser, heating to 30 ℃ under the protection of nitrogen, and starting a stirrer; slowly adding the polyethylene glycol monomethyl ether MPEG1000 without water in a dropwise manner for 3 times, wherein the total weight is 330g, and reacting for 1 hour; obtaining a reaction product I of carbamate with one end containing isocyanate group and one end containing methoxyl group;

step 2: adding 100g of tetraethylenepentamine into a flask, slowly dropwise adding the reaction product I obtained in the step 1 into the flask, slowly raising the temperature to 50 ℃ after the dropwise adding is finished, and continuously reacting for 2 hours to obtain a urea reaction product II containing a methoxyl group at one end and a primary amino group at one end;

and step 3: adding 500g of monofunctional fluorine modified epoxy reactive diluent into a flask, slowly dropwise adding the reaction product II into the flask, continuously reacting for 1h at 50 ℃, finally slowly adding 1000g of deionized water into the flask, and uniformly stirring and mixing to obtain the waterborne epoxy curing agent A3 containing the alcohol amine product.

Weighing the epoxy resin according to a certain proportion, and then adding the curing agent with the same functionality ratio. Melting and mixing at a certain temperature, and injecting into an aluminum foil mold; and then placing the mixture into a curing furnace, curing the mixture at a specified temperature, stopping heating, and naturally cooling the mixture to room temperature to obtain a cured product sample.

The contact angle of the obtained epoxy resin condensate with water is measured by adopting an OCA40 Micro surface contact angle tester of Germany Dataphysics company, 5 different smooth places on the surface of a sample are selected for measurement, the average value is taken, and the contact angle of the condensate with water reaches 96 degrees.

The water resistance of the epoxy resin cured film obtained in the above was measured according to GB/T1733-1993 paint film water resistance test method, and the results showed that no phenomena such as light loss, foaming and whitening occurred within 300 hours.

Comparative example 1

A preparation method of a water-based epoxy resin curing agent comprises the following steps:

step 1: adding 20g of isophorone diisocyanate (IPDI) into a 500mL four-neck flask with a thermometer and a condenser, adding 90g of polyether polyol N210 (polypropylene glycol ether with the molecular weight of 1000 and the functionality of 2) which is subjected to water removal treatment, starting a stirrer under the protection of nitrogen, and reacting for 1 hour at 75 ℃; cooling to 30 ℃, adding 45.04g of polyethylene glycol monomethyl ether (MPEG 1000) with water removed slowly dropwise into the mixture for four times according to the molar ratio of hydroxyl to isocyanate of 1:2, and reacting for 1 hour; obtaining a compound A with one end containing isocyanate and one end containing methoxyl;

step 2: adding 8.51g of tetraethylenepentamine into a flask according to the ratio of the amount of the residual isocyanate groups to the amount of the primary amine substances of 1:2, slowly dropwise adding the obtained compound A into the flask, slowly raising the temperature to 50 ℃ after the dropwise adding is finished, and continuously reacting for 2 hours to obtain a compound B with one end containing methoxy and one end containing primary amine;

and step 3: according to the ratio of the amount of the remaining primary amino to epoxy material1:1 monofunctional fluorine-modified epoxy reactive diluent hexafluoroisopropanol was added to the flask: 34.62g C_12-14Slowly and dropwise adding the obtained compound B into a flask, continuously reacting for 1h at 50 ℃, finally slowly adding 200g of deionized water into the flask, and uniformly stirring and mixing to obtain the waterborne epoxy curing agent B1.

Weighing the epoxy resin according to a certain proportion, and then adding the curing agent with the same functionality ratio. Melting and mixing at a certain temperature, and injecting into an aluminum foil mold; and then placing the mixture into a curing furnace, curing the mixture at a specified temperature, stopping heating, and naturally cooling the mixture to room temperature to obtain a cured product sample.

The contact angle of the obtained epoxy resin condensate with water is measured by adopting an OCA40 Micro surface contact angle tester of Germany Dataphysics company, 5 different smooth places on the surface of a sample are selected for measurement, the average value is taken, and the contact angle of the condensate with water reaches 81 degrees.

The water resistance of the epoxy resin cured film obtained in the above was measured according to GB/T1733-1993 paint film water resistance measurement method, and the results showed that no phenomena such as light loss, foaming and whitening occurred within 245 hours.

Comparative example 2

A preparation method of a water-based epoxy resin curing agent comprises the following steps:

step 1: adding 10g of isophorone diisocyanate (IPDI) into a 500mL four-neck flask with a thermometer and a condenser, heating to 40 ℃ under the protection of nitrogen, and starting a stirrer; adding slowly dropwise the PEG-monomethyl ether MPEG1000 (total 45.04 g) with water removed for four times, and reacting for 1 hour; obtaining a reaction product I of carbamate with one end containing isocyanate group and one end containing methoxyl group;

step 2: adding 8.51g of tetraethylenepentamine into a flask, slowly dropwise adding the reaction product I obtained in the step 1 into the flask, slowly raising the temperature to 70 ℃ after dropwise adding, and continuously reacting for 2 hours to obtain a reaction product II of urea with one end containing methoxy and one end containing primary amino;

and step 3: adding monofunctional fluorine modified epoxy reactive diluent into a flaskRelease agent hexafluoroisopropanol: 34.62g C_12-14Slowly and dropwise adding the reaction product II into the flask, continuously reacting for 1h at 50 ℃, finally slowly adding 200g of deionized water into the flask, and uniformly stirring and mixing to obtain the waterborne epoxy curing agent B2.

Weighing the epoxy resin according to a certain proportion, and then adding the curing agent with the same functionality ratio. Melting and mixing at a certain temperature, and injecting into an aluminum foil mold; and then placing the mixture into a curing furnace, curing the mixture at a specified temperature, stopping heating, and naturally cooling the mixture to room temperature to obtain a cured product sample.

The contact angle of the obtained epoxy resin condensate with water is measured by adopting an OCA40 Micro surface contact angle tester of Germany Dataphysics company, 5 different smooth places on the surface of a sample are selected for measurement, the average value is taken, and the contact angle of the condensate with water reaches 80 degrees.

The water resistance of the epoxy resin cured film obtained in the above was measured according to GB/T1733-1993 paint film water resistance test method, and the result showed that no phenomena such as light loss, foaming and whitening occurred within 243 hours.

Comparative example 3

A preparation method of a water-based epoxy resin curing agent comprises the following steps:

step 1: adding 10g of isophorone diisocyanate (IPDI) into a 500mL four-neck flask with a thermometer and a condenser, heating to 40 ℃ under the protection of nitrogen, and starting a stirrer; adding slowly dropwise the PEG-monomethyl ether MPEG1000 (total 45.04 g) with water removed for four times, and reacting for 1 hour; obtaining a reaction product I of carbamate with one end containing isocyanate group and one end containing methoxyl group;

step 2: adding 10.63g of tetraethylenepentamine into a flask, slowly dropwise adding the reaction product I obtained in the step 1 into the flask, slowly raising the temperature to 70 ℃ after dropwise adding, and continuously reacting for 2 hours to obtain a reaction product II of urea with one end containing methoxy and one end containing primary amino;

and step 3: the flask was charged with monofunctional fluorine modified epoxy reactive diluent hexafluoroisopropanol: 34.62g C_12-14Alkyl of (2)And (3) slowly adding glycidyl ether into the flask, dropwise adding the reaction product II into the flask, continuously reacting for 1h at 50 ℃, finally slowly adding 250g of deionized water into the flask, and uniformly stirring and mixing to obtain the waterborne epoxy curing agent B3 containing the alcohol amine product.

Weighing the epoxy resin according to a certain proportion, and then adding the curing agent with the same functionality ratio. Melting and mixing at a certain temperature, and injecting into an aluminum foil mold; and then placing the mixture into a curing furnace, curing the mixture at a specified temperature, stopping heating, and naturally cooling the mixture to room temperature to obtain a cured product sample.

The contact angle of the epoxy resin condensate obtained above with water is measured by adopting an OCA40 Micro surface contact angle tester of Germany Datophysics company, 5 different smooth places on the surface of a sample are selected for measurement, the average value is taken, and the contact angle of the epoxy resin condensate with water reaches 79 degrees.

The water resistance of the epoxy resin cured film obtained in the above was measured according to GB/T1733-1993 paint film water resistance measurement method, and the result showed that no phenomena such as light loss, foaming and whitening occurred within 236 hours.

Comparative example 4

A preparation method of a water-based epoxy resin curing agent comprises the following steps:

step 1: adding 10g of isophorone diisocyanate (IPDI) into a 500mL four-neck flask with a thermometer and a condenser, heating to 40 ℃ under the protection of nitrogen, and starting a stirrer; adding slowly dropwise the PEG-monomethyl ether MPEG1000 (total 45.04 g) with water removed for four times, and reacting for 1 hour; obtaining a reaction product I of carbamate with one end containing isocyanate group and one end containing methoxyl group;

step 2: adding 8.51g of tetraethylenepentamine into a flask, slowly dropwise adding the reaction product I obtained in the step 1 into the flask, slowly raising the temperature to 70 ℃ after dropwise adding, and continuously reacting for 2 hours to obtain a reaction product II of urea with one end containing methoxy and one end containing primary amino;

and step 3: the flask was charged with monofunctional fluorine modified epoxy reactive diluent hexafluoroisopropanol: 10g of n-butyl glycidyl ether, slowly adding the reaction product II dropwise into the flask, continuously reacting for 1h at 90 ℃, finally slowly adding 250g of deionized water into the flask, and uniformly stirring and mixing to obtain the waterborne epoxy curing agent B4 containing the alcohol amine product.

Weighing the epoxy resin according to a certain proportion, and then adding the curing agent with the same functionality ratio. Melting and mixing at a certain temperature, and injecting into an aluminum foil mold; and then placing the mixture into a curing furnace, curing the mixture at a specified temperature, stopping heating, and naturally cooling the mixture to room temperature to obtain a cured product sample.

The contact angle of the obtained epoxy resin condensate with water is measured by adopting an OCA40 Micro surface contact angle tester of Germany Dataphysics company, 5 different smooth places on the surface of a sample are selected for measurement, the average value is taken, and the contact angle of the condensate with water reaches 76 degrees.

The water resistance of the epoxy resin cured film obtained in the above was measured according to GB/T1733-1993 paint film water resistance test method, and the result showed that no phenomena such as light loss, foaming and whitening occurred within 228 hours.

Comparative example 5

A preparation method of a water-based epoxy resin curing agent comprises the following steps:

step 1: adding 45.04g of the MPEG1000 except water into a 500mL four-neck flask with a thermometer and a condenser, heating to 40 ℃ under the protection of nitrogen, and starting a stirrer; adding 10g of isophorone diisocyanate (IPDI) according to the molar ratio of hydroxyl to isocyanate groups being 1:2, and reacting for 1 hour; obtaining a compound A with one end containing isocyanate and one end containing methoxyl;

step 2: adding 8.51g of tetraethylenepentamine into a flask according to the ratio of the amount of the residual isocyanate groups to the amount of the primary amine substances of 1:2, slowly dropwise adding the obtained compound A into the flask, slowly raising the temperature to 70 ℃ after dropwise adding, and continuously reacting for 2 hours to obtain a compound B with one end containing methoxy and one end containing primary amine;

and step 3: adding a monofunctional fluorine modified epoxy reactive diluent hexafluoroisopropanol into a flask according to the ratio of the amount of the residual primary amino to epoxy materials being 1: 5.86g of n-butyl glycidyl ether, slowly adding the obtained compound B dropwise into the flask, continuously reacting for 1h at 50 ℃, finally slowly adding 250g of deionized water into the flask, and uniformly stirring and mixing to obtain the waterborne epoxy curing agent B5.

Weighing the epoxy resin according to a certain proportion, and then adding the curing agent with the same functionality ratio. Melting and mixing at a certain temperature, and injecting into an aluminum foil mold; and then placing the mixture into a curing furnace, curing the mixture at a specified temperature, stopping heating, and naturally cooling the mixture to room temperature to obtain a cured product sample.

The contact angle of the obtained epoxy resin condensate with water is measured by adopting an OCA40 Micro surface contact angle tester of Germany Dataphysics company, 5 different smooth places on the surface of a sample are selected for measurement, the average value is taken, and the contact angle of the condensate with water reaches 85 degrees.

The water resistance of the epoxy resin cured film obtained in the above was measured according to GB/T1733-1993 paint film water resistance test method, and the results showed that no phenomena such as light loss, foaming and whitening occurred within 240 hours.

The test data for examples 1-3 and comparative examples 1-5 are shown in Table 2.

TABLE 2

		Contact angle (°)	Water resistance (h)
				Example 1	A1	98	308
Example 2	A2	95	296
				Example 3	A3	96	300
Comparative example 1	B1	81	245
				Comparative example 2	B2	80	243
Comparative example 3	B3	79	236
				Comparative example 4	B4	76	228
Comparative example 5	B5	82	240