CN113667378A - Graphene electrophoretic paint and preparation method thereof - Google Patents

Abstract

The invention discloses graphene electrophoretic paint which comprises modified epoxy resin generated by the reaction of epoxy resin, graphene oxide, surface-treated carbon nanotubes and surface-treated silicon carbide; the mass ratio of the graphene oxide to the surface-treated carbon nanotube to the surface-treated silicon carbide is 7-9:1-3: 1. The graphene electrophoretic paint provided by the invention has higher dispersion uniformity and stability, and the anticorrosive performance of the electrophoretic paint coating is good.

Description

Graphene electrophoretic paint and preparation method thereof

Technical Field

The invention relates to the technical field of electrophoretic paint, in particular to graphene electrophoretic paint and a preparation method thereof.

Background

Graphene is the thinnest anticorrosive material in the world and can be used for protecting metal substrates, and related researches on graphene anticorrosive coatings have been carried out for a while. A large number of research results show that the graphene has properties of an ultra-large radius-thickness ratio, excellent barrier property, good conductivity and the like, has a strong effect of improving the comprehensive performance of the anticorrosive paint, such as enhancing the adhesive force of a coating to a base material, improving the wear resistance and the corrosion resistance of the paint, and has the characteristics of environmental protection, safety, no secondary pollution and the like.

Since the beginning of research on cathode electrophoretic coatings, the cathode electrophoretic coatings have been widely applied to industries such as automobiles, engineering equipment, electronic instruments and the like by virtue of excellent properties of the cathode electrophoretic coatings. With the development of science and technology, some industries with higher precision requirements such as navigation and aviation have higher and higher requirements on the performance of a coating film, such as high corrosion resistance, high strength and the like, and the requirements on the coating process are also stricter and stricter, and the continuous improvement of the performance of the coating film and the optimization of the coating process are research trends of cathode electrophoretic coatings.

Disclosure of Invention

Aiming at the problems in the prior art, the invention provides graphene electrophoretic paint and a preparation method thereof. The graphene electrophoretic paint provided by the invention has higher dispersion uniformity and stability, and the anticorrosive performance of the electrophoretic paint coating is good.

The technical scheme of the invention is as follows:

the graphene electrophoretic paint comprises modified epoxy resin generated by the reaction of epoxy resin, graphene oxide, surface-treated carbon nanotubes and surface-treated silicon carbide.

Silicon carbide in the present invention refers to nano silicon carbide.

Preferably, the surface-treated carbon nanotubes are graphene oxide coated carbon nanotubes; the surface-treated silicon carbide is silicon carbide coated with graphene oxide.

Preferably, the carbon nanotubes are subjected to a pretreatment process of oxidation and silane modification before the graphene oxide coating treatment of the carbon nanotubes.

Preferably, the mass ratio of the epoxy resin, the graphene oxide, the surface-treated carbon nanotubes and the surface-treated silicon carbide is 8-15:7-9:1-3: 1.

Preferably, the sum of the mass percentages of the graphene oxide, the surface-treated carbon nanotubes and the surface-treated silicon carbide is 0.01-1% based on the mass of the graphene electrophoretic paint.

Preferably, the epoxy resin has an epoxy equivalent of 500 or less. Preferably, the modified epoxy resin has an epoxy equivalent of 4000 to 5000.

A preparation method of the graphene electrophoretic paint comprises a preparation step of modified epoxy resin, and the preparation step comprises the following steps:

(1) preparing a graphene oxide dispersion liquid;

preferably, the preparation method of the graphene oxide dispersion liquid comprises the following steps: dispersing graphene oxide in deionized water, and uniformly stirring to obtain a graphene oxide dispersion liquid;

preferably, the mass ratio of the graphene oxide to the deionized water is 7-9: 100;

preferably, the stirring speed is 200-500rpm, and the stirring time is 1-4 h;

(2) dispersing the pretreated carbon nano tubes and silicon carbide in the graphene oxide dispersion liquid obtained in the step (1), and stirring and mixing to obtain a mixed dispersion liquid of graphene oxide, surface-treated carbon nano tubes and surface-treated silicon carbide;

preferably, the preparation method of the pretreated carbon nanotubes and silicon carbide comprises the following steps:

respectively placing the carbon nano tube and the silicon carbide particles in a mixed solution of hydrogen peroxide and concentrated sulfuric acid, soaking for 4-6h at 50-70 ℃, and then drying to respectively obtain an oxidized carbon nano tube and oxidized silicon carbide;

dispersing the oxidized carbon nano tube and the oxidized silicon carbide in a silane coupling agent A151 aqueous solution, performing ultrasonic dispersion for 2-5h at the temperature of 60-100 ℃, and drying to obtain an A151 modified carbon nano tube and silicon carbide, namely the pretreated carbon nano tube and the pretreated silicon carbide;

preferably, the mass ratio of the hydrogen peroxide to the concentrated sulfuric acid is 1: 3-5; the mass concentration of the hydrogen peroxide is 30 percent; the mass concentration of the concentrated sulfuric acid is 90-98%;

preferably, the mass ratio of the oxidized carbon nanotubes to the oxidized silicon carbide is 1-3: 1;

preferably, the dosage of the A151 aqueous solution is 1-5 times of the total mass of the carbon nano tube and the silicon carbide; the mass concentration of the silane coupling agent A151 aqueous solution is 20-30%.

The pretreatment can solve the problem that the dispersion effect and the stability are influenced because the surface groups of the carbon nano tube and the nano silicon carbide are few and cannot be subjected to chemical grafting reaction with the matrix resin;

(3) mixing epoxy resin and a chain extender with the mixed dispersion liquid obtained in the step (2), and heating to obtain a dispersion liquid of the modified epoxy resin;

preferably, the chain extender is selected from one or more of bisphenol a, bismaleimide, 1, 4-butanediol and derivatives thereof;

preferably, in the step (3), a stabilizer is further included, and the stabilizer is triphenylphosphine;

preferably, the proportion of the epoxy resin, the chain extender and the stabilizer is 80-150:2-5:2-5 by weight.

Preferably, in the step (3), the specific process is as follows: adding a chain extender and a stabilizer into the epoxy resin dispersion liquid, preserving the heat for 1-4h at the temperature of 30-60 ℃, then heating to the temperature of 120-;

preferably, the epoxy resin dispersion is prepared by the following method: dispersing 80-150 parts by weight of epoxy resin in 1000 parts by weight of deionized water, and uniformly stirring to obtain epoxy resin dispersion liquid;

preferably, in the step (3), the mixed dispersion obtained in the step (2) is added by a micro syringe pump.

In some embodiments, the method of preparing the graphene electrophoretic paint is: heating 100 parts of modified epoxy resin dispersion liquid to 70-80 ℃, stirring until the modified epoxy resin is completely dissolved, dropwise adding 5-10 parts of amine modifier at a controlled temperature for amination reaction, heating to 100 ℃ and 130 ℃ after the reaction is finished, adding 5-10 parts of enclosed isocyanate curing agent and 10-15 parts of neutralizer for reaction to obtain a main emulsion, and mixing the main emulsion and the color paste to prepare the graphene electrophoretic paint.

Preferably, the amine-based modifier is any amine in the art that can be used in an electrophoretic paint, including but not limited to monoethanolamine, diethanolamine, N-dimethylethanolamine, polyamide.

Preferably, the neutralizing agent is any neutralizing agent that may be used in electrophoretic paints in the art, including but not limited to lactic acid, glacial acetic acid, formic acid.

The beneficial technical effects of the invention are as follows:

according to the invention, a combined adding mode of graphene oxide, carbon nano tubes and nano silicon carbide is adopted, and the graphene oxide and the carbon nano tubes are subjected to surface reaction with matrix resin in advance to form a composite structure, so that the dispersion uniformity and stability in the electrophoretic paint are improved, and the corrosion resistance is better improved. The graphene is of a lamellar net structure, the carbon nano tube is of a linear structure, the silicon carbide is of a point structure, and the corrosion resistance of the coating can be improved to a certain extent when the SiC material is added into the coating due to the stability of the SiC material.

The invention adopts the surface line point combination consisting of graphene, carbon nano tubes and nano silicon carbide powder, and has the main functions of: (1) a wide surface + line + point barrier network can be formed, and the composite labyrinth structure can slow down the corrosion of the substrate caused by the water and air passing through the coating; (2) the graphene and the carbon nano tube are both materials with excellent conductivity, and can conduct electrons generated by corrosion reaction on the surface of the base material to the surface of the coating to prevent further corrosion reaction.

According to the invention, graphene oxide is selected, the graphene oxide has thin (less than or equal to 20) sheet layers, and meanwhile, the surface of the graphene oxide contains rich oxygen-containing groups, so that the graphene oxide and epoxy resin can conveniently carry out chemical grafting reaction.

According to the invention, the surfaces of the carbon nano tube and the silicon carbide which are pretreated are coated with the graphene oxide, and the carbon tube and the silicon carbide participate in the chain extension reaction of the epoxy resin by utilizing the surface grafting group after the surface treatment, so that the dispersion uniformity and stability in the resin are improved, and the corrosion resistance is better improved.

Detailed Description

The present invention will be described in detail with reference to examples.

Example 1

A preparation method of graphene electrophoretic paint comprises the following steps: the raw materials are counted by weight;

(1) preparation of graphene oxide Dispersion

And dispersing 70 parts of graphene oxide in 1000 parts of deionized water, stirring at 400rpm for 2 hours, and uniformly stirring to obtain the graphene oxide dispersion liquid.

(2) Preparation of graphene oxide-coated carbon nanotubes and silicon carbide

Respectively placing the carbon nano tube and the nano silicon carbide particles in a mixed solution (the mass ratio of hydrogen peroxide to concentrated sulfuric acid is 1:5) of hydrogen peroxide (the mass concentration is 30%) and concentrated sulfuric acid (the mass concentration is 90%), soaking for 4 hours at 70 ℃, and then drying to respectively prepare an oxidized carbon nano tube and oxidized silicon carbide;

and (2) placing 30 parts of oxidized carbon nano tube and 10 parts of oxidized silicon carbide in 100 parts of A151 aqueous solution (with the mass concentration of 25%), performing ultrasonic dispersion for 2 hours at 100 ℃, and drying to obtain the A151 modified carbon nano tube and silicon carbide.

Adding the A151 modified carbon nano tube and silicon carbide into the graphene oxide dispersion liquid prepared in the step (1), and mechanically stirring for 4 hours; converting the A151 modified carbon nano tube and the silicon carbide into a graphene oxide coated carbon nano tube and silicon carbide by charge attraction to prepare a mixed dispersion of the graphene oxide, the surface treated carbon nano tube and the surface treated silicon carbide;

(3) preparation of modified epoxy resin

Fully mixing 100 parts of epoxy resin (epoxy equivalent of 300) and 1000 parts of water by mechanical stirring for 4 hours, then adding 3 parts of bisphenol A and 5 parts of triphenylphosphine, and preserving heat for 4 hours at 40 ℃;

and (3) slowly heating to 150 ℃, adding the mixed dispersion liquid obtained in the step (2) through a micro-injection pump, and carrying out chain extension reaction to obtain the dispersion liquid of the modified epoxy resin, wherein the epoxy equivalent of the modified epoxy resin is 4700.

(4) Preparation of graphene electrophoretic paint

Adding 100 parts of modified epoxy resin dispersion into a three-neck flask, heating to 80 ℃, stirring until the modified epoxy resin is completely dissolved, dropwise adding 8 parts of diethanolamine at controlled temperature for amination reaction, heating to 110 ℃ after the reaction is finished, continuously adding 5 parts of enclosed isocyanate curing agent and 10 parts of formic acid into the container for reaction to prepare main emulsion, and then mixing the main emulsion, color paste and water according to the ratio of 6:1:8 to prepare the graphene electrophoretic paint.

Example 2

A preparation method of graphene electrophoretic paint comprises the following steps: the raw materials are counted by weight;

(1) preparation of graphene oxide Dispersion

And dispersing 90 parts of graphene oxide in 1000 parts of deionized water, stirring at 500rpm for 2 hours, and uniformly stirring to obtain the graphene oxide dispersion liquid.

(2) Preparation of graphene oxide-coated carbon nanotubes and silicon carbide

Respectively placing the carbon nano tube and the nano silicon carbide particles in a mixed solution (the mass ratio of hydrogen peroxide to concentrated sulfuric acid is 1:3) of hydrogen peroxide (the mass concentration is 30%) and concentrated sulfuric acid (the mass concentration is 90%), soaking for 4 hours at 50 ℃, and then drying to respectively prepare an oxidized carbon nano tube and oxidized silicon carbide;

and (2) placing 20 parts of oxidized carbon nano tube and 10 parts of oxidized silicon carbide in 100 parts of A151 aqueous solution (with the mass concentration of 20%), performing ultrasonic dispersion for 4 hours at 80 ℃, and drying to obtain the A151 modified carbon nano tube and silicon carbide.

Adding the A151 modified carbon nano tube and silicon carbide into the graphene oxide dispersion liquid prepared in the step (1), and mechanically stirring for 4 hours; converting the A151 modified carbon nano tube and the silicon carbide into a graphene oxide coated carbon nano tube and silicon carbide by charge attraction to prepare a mixed dispersion of the graphene oxide, the surface treated carbon nano tube and the surface treated silicon carbide;

(3) preparation of modified epoxy resin

Mechanically stirring 150 parts of epoxy resin (epoxy equivalent of 300) and 1000 parts of water, fully mixing for 4 hours, then adding 5 parts of bisphenol A and 5 parts of triphenylphosphine, and preserving heat for 3 hours at 40 ℃;

and (3) slowly heating to 120 ℃, adding the mixed dispersion liquid obtained in the step (2) through a micro-injection pump, and carrying out chain extension reaction to obtain the dispersion liquid of the modified epoxy resin, wherein the epoxy equivalent of the modified epoxy resin is 4500.

(4) Preparation of graphene electrophoretic paint

Adding 100 parts of modified epoxy resin dispersion into a three-neck flask, heating to 80 ℃, stirring until the modified epoxy resin is completely dissolved, dropwise adding 8 parts of diethanolamine at controlled temperature for amination reaction, heating to 110 ℃ after the reaction is finished, continuously adding 5 parts of enclosed isocyanate curing agent and 10 parts of formic acid into the container for reaction to prepare main emulsion, and then mixing the main emulsion, color paste and water according to the ratio of 6:1:8 to prepare the graphene electrophoretic paint.

Example 3

A preparation method of graphene electrophoretic paint comprises the following steps: the raw materials are counted by weight;

(1) preparation of graphene oxide Dispersion

And dispersing 80 parts of graphene oxide in 1000 parts of deionized water, stirring at 200rpm for 4 hours, and uniformly stirring to obtain the graphene oxide dispersion liquid.

(2) Preparation of graphene oxide-coated carbon nanotubes and silicon carbide

Respectively placing carbon nano tubes and nano silicon carbide particles into a mixed solution (the mass ratio of hydrogen peroxide to concentrated sulfuric acid is 1:3) of hydrogen peroxide (the mass concentration is 30%) and concentrated sulfuric acid (the mass concentration is 98%), soaking for 6 hours at 50 ℃, and then drying to respectively prepare oxidized carbon nano tubes and oxidized silicon carbide;

and (2) placing 10 parts of oxidized carbon nano tube and 10 parts of oxidized silicon carbide in 100 parts of A151 aqueous solution (with the mass concentration of 20%), performing ultrasonic dispersion for 5 hours at the temperature of 60 ℃, and drying to obtain the A151 modified carbon nano tube and silicon carbide.

Adding the A151 modified carbon nano tube and silicon carbide into the graphene oxide dispersion liquid prepared in the step (1), and mechanically stirring for 4 hours; converting the A151 modified carbon nano tube and the silicon carbide into a graphene oxide coated carbon nano tube and silicon carbide by charge attraction to prepare a mixed dispersion of the graphene oxide, the surface treated carbon nano tube and the surface treated silicon carbide;

(3) preparation of modified epoxy resin

Mechanically stirring 80 parts of epoxy resin (epoxy equivalent of 300) and 1000 parts of water, fully mixing for 4 hours, then adding 2 parts of bisphenol A and 2 parts of triphenylphosphine, and preserving heat for 2 hours at 40 ℃;

and (3) slowly heating to 160 ℃, adding the mixed dispersion liquid obtained in the step (2) through a micro-injection pump, and carrying out chain extension reaction to obtain the dispersion liquid of the modified epoxy resin, wherein the epoxy equivalent of the modified epoxy resin is 4300.

(4) Preparation of graphene electrophoretic paint

Adding 100 parts of modified epoxy resin dispersion into a three-neck flask, heating to 80 ℃, stirring until the modified epoxy resin is completely dissolved, dropwise adding 8 parts of diethanolamine at controlled temperature for amination reaction, heating to 110 ℃ after the reaction is finished, continuously adding 5 parts of enclosed isocyanate curing agent and 10 parts of formic acid into the container for reaction to prepare main emulsion, and then mixing the main emulsion, color paste and water according to the ratio of 6:1:8 to prepare the graphene electrophoretic paint.

Comparative example 1

A preparation method of electrophoretic paint comprises the following steps: the raw materials are counted by weight;

(1) synthesis of macromolecular epoxy resin

Adding 100 parts of micromolecular basic epoxy resin (epoxy equivalent weight is 300) and 1000 parts of water into a reaction container, mechanically stirring and fully mixing for 2 hours, then adding 3 parts of bisphenol A and 5 parts of triphenylphosphine, and keeping the temperature at 40 ℃ for 2 hours; and slowly raising the temperature of the reaction vessel to 150 ℃, and carrying out chain extension reaction to obtain the macromolecular epoxy resin (epoxy equivalent 4000) dispersion liquid.

(2) Preparation of electrophoretic paints

Adding 100 parts of the epoxy resin dispersion prepared in the step (1) into a three-neck flask, heating to 80 ℃, stirring until the epoxy resin is completely dissolved, controlling the temperature, dropwise adding 8 parts of diethanolamine to carry out amination reaction, heating to 110 ℃ after the reaction is finished, and continuously adding 5 parts of closed isocyanate curing agent and 10 parts of formic acid into the container to carry out reaction to prepare main emulsion. And then mixing the main emulsion, color paste and water according to the ratio of 6:1:8 to prepare the electrophoretic paint.

Comparative example 2

A preparation method of graphene electrophoretic paint comprises the following steps: the raw materials are counted by weight;

(1) preparation of mixed dispersion liquid of graphene oxide, carbon tube and nano silicon carbide

Adding 20 parts of polyvinylpyrrolidone dispersing agent into 1000 parts of deionized water, uniformly stirring, adding 70 parts of graphene oxide powder, 30 parts of dried carbon nano tube and 10 parts of silicon carbide, and mechanically stirring for 2 hours to prepare a dispersion liquid;

(2) preparation of modified epoxy resin electrophoretic paint coating

Adding 100 parts of micromolecular basic epoxy resin (epoxy equivalent weight is 300) and 1000 parts of water into a reaction container, and mechanically stirring and fully mixing for 2 hours; and (2) adding 3 parts of bisphenol A and 5 parts of triphenylphosphine, keeping the temperature at 40 ℃ for 2 hours, heating to 150 ℃, adding the dispersion liquid prepared in the step (1) for chain extension reaction, and finally obtaining the dispersion liquid containing the macromolecular modified epoxy resin (epoxy equivalent 4000).

(3) Preparation of graphene electrophoretic paint

Adding 100 parts of the dispersion liquid prepared in the step (2) into a three-neck flask, heating to 80 ℃, stirring until epoxy resin is completely dissolved, dropwise adding 8 parts of diethanolamine at controlled temperature for amination reaction, heating to 110 ℃ after the reaction is finished, continuously adding 5 parts of closed isocyanate curing agent and 10 parts of formic acid into the container for reaction to prepare a main emulsion, and then mixing the main emulsion, color paste and water according to the ratio of 6:1:8 to prepare the graphene electrophoretic paint.

Test example:

the electrophoretic paints obtained in examples 1-3 and comparative examples 1-2 were subjected to substrate electrophoresis, respectively; the electrophoresis test piece is made of DC06 stainless steel, and the steel piece is degreased and phosphated before the experiment. Connecting the cleaned and dried steel sheet with a power supply cathode, wherein the power supply anode is a tinned steel sheet, the cathode and the anode are vertically and parallelly arranged on two sides of an electrolytic tank, the distance between the cathode and the anode is 150-200 mm, adding the prepared graphene electrophoretic paint, adjusting the electrophoretic voltage to be 100V, timing for 2min, washing the electrophoresed test piece with deionized water, and then placing the test piece in an oven for curing; the results of the performance tests of the obtained electrophoretic coating are shown in table 1. As can be seen from the data in Table 1, the electrodeposition paint of the present invention has better corrosion resistance than the comparative examples.

TABLE 1

Examples	Coating thickness/. mu.m	Adhesion/grade	Hardness of	Decay-resistant time/h
					Example 1	25	0	HB	1560
Example 2	25	0	HB	1900
					Example 3	25	0	HB	1680
Comparative example 1	25	0	HB	480
					Comparative example 2	25	2	B	600
Standard of merit	GB/T13452.2-2008	GB/T9286-1988	GB/T6739	GB/T10125-2012

Claims (10)

1. The graphene electrophoretic paint is characterized by comprising modified epoxy resin generated by the reaction of epoxy resin, graphene oxide, surface-treated carbon nanotubes and surface-treated silicon carbide.

2. The graphene electrophoretic paint according to claim 1, wherein the surface-treated carbon nanotubes are graphene oxide-coated carbon nanotubes; the surface-treated silicon carbide is silicon carbide coated by graphene oxide;

preferably, the mass ratio of the epoxy resin, the graphene oxide, the surface-treated carbon nanotubes and the surface-treated silicon carbide is 8-15:7-9:1-3: 1;

preferably, the sum of the mass percentages of the graphene oxide, the surface-treated carbon nanotubes and the surface-treated silicon carbide is 0.01-1% based on the mass of the graphene electrophoretic paint.

3. The graphene electrophoretic paint according to claim 2, wherein the carbon nanotubes are subjected to a pretreatment process of oxidation and silane modification before the graphene oxide coating process of the carbon nanotubes.

4. The graphene electrophoretic paint according to claim 1, wherein the epoxy resin has an epoxy equivalent of 500 or less;

preferably, the modified epoxy resin has an epoxy equivalent of 4000 to 5000.

5. A method for preparing the graphene electrophoretic paint according to claim 1, wherein the method comprises a step of preparing a modified epoxy resin, and the step of preparing comprises the following steps:

(1) preparing a graphene oxide dispersion liquid;

(2) dispersing the pretreated carbon nano tubes and silicon carbide in the graphene oxide dispersion liquid obtained in the step (1), and stirring and mixing to obtain a mixed dispersion liquid of graphene oxide, surface-treated carbon nano tubes and surface-treated silicon carbide;

(3) and (3) mixing the epoxy resin and the chain extender with the mixed dispersion liquid obtained in the step (2), and heating to obtain the modified epoxy resin dispersion liquid.

6. The method according to claim 5, wherein in the step (1), the graphene oxide dispersion liquid is prepared by: dispersing graphene oxide in deionized water, and uniformly stirring to obtain a graphene oxide dispersion liquid;

preferably, the mass ratio of the graphene oxide to the deionized water is 7-9: 100;

preferably, the rotation speed of the stirring is 200-500rpm, and the stirring time is 1-4 h.

7. The method according to claim 5, wherein the pretreated carbon nanotubes and silicon carbide are prepared in step (2) by:

respectively placing the carbon nano tube and the silicon carbide particles in a mixed solution of hydrogen peroxide and concentrated sulfuric acid, soaking for 4-6h at 50-70 ℃, and then drying to respectively obtain an oxidized carbon nano tube and oxidized silicon carbide;

dispersing the oxidized carbon nano tube and the oxidized silicon carbide in a silane coupling agent A151 aqueous solution, performing ultrasonic dispersion for 2-5h at the temperature of 60-100 ℃, and drying to obtain an A151 modified carbon nano tube and silicon carbide;

preferably, the mass ratio of the hydrogen peroxide to the concentrated sulfuric acid is 1: 3-5; the mass concentration of the hydrogen peroxide is 30 percent; the mass concentration of the concentrated sulfuric acid is 90-98%;

preferably, the mass ratio of the oxidized carbon nanotubes to the oxidized silicon carbide is 1-3: 1;

preferably, the dosage of the A151 aqueous solution is 1-5 times of the total mass of the carbon nano tube and the silicon carbide; the mass concentration of the silane coupling agent A151 aqueous solution is 20-30%.

8. The method according to claim 5, wherein in the step (3), the chain extender is one or more selected from the group consisting of bisphenol A, bismaleimide, 1, 4-butanediol, and derivatives thereof.

9. The method according to claim 5, wherein in the step (3), a stabilizer is further included, and the stabilizer is triphenylphosphine;

preferably, the proportion of the epoxy resin, the chain extender and the stabilizer is 80-150:2-5:2-5 by weight.

10. The preparation method according to claim 5, wherein in the step (3), the specific process is as follows: adding a chain extender and a stabilizer into the epoxy resin dispersion liquid, preserving the heat for 1-4h at the temperature of 30-60 ℃, then heating to the temperature of 120-;

preferably, the epoxy resin dispersion is prepared by the following method: dispersing 80-150 parts by weight of epoxy resin in 1000 parts by weight of deionized water, and uniformly stirring to obtain epoxy resin dispersion liquid;

preferably, the mixed dispersion obtained in step (2) is added by a micro-syringe pump.