CN118599394A - A two-component epoxy primer with ultra-long activation period and its preparation method and application - Google Patents

Abstract

The invention provides a double-component epoxy primer with an ultra-long activation period, and a preparation method and application thereof, and belongs to the technical field of epoxy coatings. The double-component epoxy primer with the ultra-long activation period comprises a component A and a component B which are packaged separately; the mass ratio of the two is 1.5-2.5: 1, a step of; the component B comprises 3986 curing agent, propylene glycol methyl ether and water; the component A comprises the following components in parts by mass: 35-55 parts of JT-WBE522 aqueous epoxy emulsion; 1-3 parts of dispersing agent; 0.3 to 0.5 part of defoaming agent; 5-10 parts of titanium dioxide; 5-15 parts of mica powder; 10-15 parts of wollastonite; 5-10 parts of talcum powder; 0.1 to 0.5 part of carbon black; 0.2 to 0.5 part of silane coupling agent; 0.5 to 1 part of flash rust prevention auxiliary agent; 0.2 to 0.5 part of thickener; 0.1 to 0.3 part of wetting agent; 3-10 parts of cosolvent; 10-20 parts of water. The double-component epoxy primer has an ultra-long activation period.

Description

A two-component epoxy primer with ultra-long activation period and its preparation method and application

Technical Field

The invention relates to the technical field of epoxy coatings, and in particular to a two-component epoxy primer with an ultra-long activation period, and a preparation method and application thereof.

Background Art

Epoxy primer can give the coating good adhesion, and has excellent chemical stability and mechanical properties, and is widely used. In the prior art, the activation period of epoxy primers is mostly 4 to 6 hours, and the activation period of some types of epoxy primers can reach about 8 hours. When using certain processes to apply epoxy primers, it is required to have a longer activation period. For example, in the transformer coating process, the activation period of epoxy primers is usually required to be at least 12 hours. This is mainly because the current actual production is generally a three-shift work environment, and at least 1 hour is required to be reserved for handover. If the activation period of the epoxy primer is short, it cannot meet the actual application and affect the smooth progress of production.

Summary of the invention

The purpose of the present invention is to provide a two-component epoxy primer with an ultra-long activation period, a preparation method and an application thereof. The two-component epoxy primer provided by the present invention has an ultra-long activation period.

In order to achieve the above-mentioned object of the invention, the present invention provides the following technical solutions:

The present invention provides a two-component epoxy primer with an ultra-long activation period, comprising a separately packaged component A and a component B; the mass ratio of the component A to the component B is 1.5-2.5:1;

The B component includes 3986 curing agent, propylene glycol methyl ether and water;

The component A includes the following components in parts by mass: 35 to 55 parts of JT-WBE522 water-based epoxy emulsion; 1 to 3 parts of dispersant; 0.3 to 0.5 parts of defoamer; 5 to 10 parts of titanium dioxide; 5 to 15 parts of mica powder; 10 to 15 parts of wollastonite; 5 to 10 parts of talc; 0.1 to 0.5 parts of carbon black; 0.2 to 0.5 parts of silane coupling agent; 0.5 to 1 part of anti-flash rust additive; 0.2 to 0.5 parts of thickener; 0.1 to 0.3 parts of wetting agent; 3 to 10 parts of cosolvent; and 10 to 20 parts of water.

Preferably, the mass ratio of 3986 curing agent, propylene glycol methyl ether and water in the B component is 20:4-6:18-22.

Preferably, the dispersant is BYK190 dispersant, and the defoamer is BYK-028 defoamer.

Preferably, the titanium dioxide is R996 rutile titanium dioxide; the mica powder is GA-4 mica powder; and the carbon black is MA-100 carbon black.

Preferably, the silane coupling agent is MP-200 silane coupling agent; and the anti-flash rust agent is Raybo 60 anti-flash rust agent.

Preferably, the thickener is 0620 thickener; the wetting agent is 4100 wetting agent; and the cosolvent is dipropylene glycol butyl ether and/or dipropylene glycol methyl ether.

Preferably, the fineness of component A is ≤30 μm, and the solid content is ≥46 wt %; and the solid content of component B is ≥20 wt %.

The present invention provides a method for preparing the ultra-long active period two-component epoxy primer according to the above technical solution, comprising the following steps:

Mix water, dispersant, mica powder, titanium dioxide, wollastonite, talc, carbon black and part of the defoamer and grind them to obtain a grinding slurry; mix the grinding slurry, JT-WBE522 water-based epoxy emulsion, cosolvent, thickener, wetting agent, silane coupling agent, anti-flash rust additive and the remaining defoamer to obtain the A component;

The 3986 curing agent, propylene glycol methyl ether and water are mixed to obtain the B component.

Preferably, the grinding temperature is ≤50°C, the pressure is ≤0.2MPa; and the fineness of the grinding slurry is ≤20μm.

The present invention provides the use of the ultra-long activation period two-component epoxy primer described in the above technical solution or the ultra-long activation period two-component epoxy primer prepared by the preparation method described in the above technical solution in transformer spray coating.

The invention provides a super-long active period two-component epoxy primer, comprising separately packaged component A and component B; the mass ratio of the component A to the component B is 1.5-2.5:1; the component B comprises a 3986 curing agent, propylene glycol methyl ether and water; the component A comprises the following components in parts by mass: 35-55 parts of JT-WBE522 water-based epoxy emulsion; 1-3 parts of a dispersant; 0.3-0.5 parts of a defoamer; 5-10 parts of titanium dioxide; 5-15 parts of mica powder; 10-15 parts of wollastonite; 5-10 parts of talc; 0.1-0.5 parts of carbon black; 0.2-0.5 parts of a silane coupling agent; 0.5-1 parts of an anti-flash rust additive; 0.2-0.5 parts of a thickener; 0.1-0.3 parts of a wetting agent; 3-10 parts of a cosolvent; and 10-20 parts of water. The present invention utilizes JT-WBE522 waterborne epoxy emulsion and 3986 curing agent as the main components of component A and component B respectively, and the two are compounded and under the comprehensive effect of other components, the obtained two-component epoxy primer is guaranteed to have an ultra-long activation period. In addition, the two-component epoxy primer in the present invention also has good salt spray resistance. The results of the embodiment show that the activation period of the two-component epoxy primer provided by the present invention can reach 24 hours, and the salt spray resistance can reach 800 hours.

DETAILED DESCRIPTION

The present invention provides a two-component epoxy primer with an ultra-long activation period, comprising a separately packaged component A and a component B; the mass ratio of the component A to the component B is 1.5-2.5:1;

The B component includes 3986 curing agent, propylene glycol methyl ether and water;

The component A includes the following components in parts by mass: 35 to 55 parts of JT-WBE522 water-based epoxy emulsion; 1 to 3 parts of dispersant; 0.3 to 0.5 parts of defoamer; 5 to 10 parts of titanium dioxide; 5 to 15 parts of mica powder; 10 to 15 parts of wollastonite; 5 to 10 parts of talc; 0.1 to 0.5 parts of carbon black; 0.2 to 0.5 parts of silane coupling agent; 0.5 to 1 part of anti-flash rust additive; 0.2 to 0.5 parts of thickener; 0.1 to 0.3 parts of wetting agent; 3 to 10 parts of cosolvent; and 10 to 20 parts of water.

In the present invention, unless otherwise specified, the raw materials used are commercially available products well known to those skilled in the art.

The ultra-long active period two-component epoxy primer of the present invention comprises separately packaged component A and component B; the mass ratio of component A to component B is 1.5-2.5:1, preferably 1.8-2.2:1, and more preferably 2:1.

The B component of the present invention includes 3986 curing agent, propylene glycol methyl ether (PM) and water; the mass ratio of 3986 curing agent, propylene glycol methyl ether and water in the B component is preferably 20:4-6:18-22, more preferably 20:5:20.

In parts by mass, the component A of the present invention includes 35 to 55 parts of JT-WBE522 water-based epoxy emulsion, specifically 35 parts, 38 parts, 40 parts, 42 parts, 45 parts, 48 parts, 50 parts, 53 parts or 55 parts.

Based on the mass fraction of the JT-WBE522 waterborne epoxy emulsion, the component A of the present invention includes 1 to 3 parts of dispersant, preferably 1.5 to 2.5 parts, and more preferably 2 parts. The dispersant of the present invention is preferably BYK190 dispersant. The present invention preferably uses the above-mentioned type of dispersant, which is conducive to maintaining a good dispersion effect of each component.

Based on the mass fraction of the JT-WBE522 waterborne epoxy emulsion, the component A of the present invention includes 0.3 to 0.5 parts of defoamer, preferably 0.3 to 0.4 parts. The defoamer of the present invention is preferably BYK-028 defoamer. The present invention preferably uses the above-mentioned type of defoamer, which has a better defoaming effect.

Based on the mass fraction of the JT-WBE522 waterborne epoxy emulsion, the component A of the present invention includes 5 to 10 parts of titanium dioxide, preferably 5 to 8 parts, and more preferably 5 to 6 parts. The titanium dioxide of the present invention is preferably R996 rutile titanium dioxide; the particle size of the titanium dioxide is preferably 0.1 to 0.45 μm. The present invention preferably uses the above-mentioned type of titanium dioxide, which has a small particle size and is conducive to dispersion and grinding.

Based on the mass fraction of the JT-WBE522 waterborne epoxy emulsion, the component A of the present invention includes 5 to 15 parts of mica powder, preferably 8 to 12 parts, and more preferably 9 to 10 parts. The mica powder of the present invention is preferably GA-4 mica powder; the particle size of the mica powder is preferably 5 to 10 μm. The present invention preferably uses the above-mentioned type of mica powder, which has a small particle size and better salt spray resistance, which is beneficial to improving the salt spray resistance of the coating.

Based on the mass fraction of the JT-WBE522 water-based epoxy emulsion, the component A of the present invention includes 10 to 15 parts of wollastonite, preferably 10 to 13 parts, and more preferably 10 to 11 parts. The particle size of the wollastonite of the present invention is preferably 1250 mesh. The present invention preferably uses the above-mentioned type of wollastonite, whose needle-like structure is conducive to filling the gaps between the paint films to achieve better salt spray resistance.

Based on the mass fraction of the JT-WBE522 waterborne epoxy emulsion, the component A of the present invention includes 5 to 10 parts of talc, preferably 5 to 8 parts, and more preferably 5 to 6 parts. The particle size of the talc of the present invention is preferably 1250 mesh. The present invention preferably uses the above-mentioned type of talc, which is beneficial to shielding water vapor and improving the salt spray resistance of the coating.

Based on the mass fraction of the JT-WBE522 waterborne epoxy emulsion, the component A of the present invention includes 0.1 to 0.5 parts of carbon black, preferably 0.2 to 0.4 parts, and more preferably 0.3 parts. The carbon black of the present invention is preferably MA-100 carbon black; the particle size of the carbon black is preferably 10 to 100 μm. In the present invention, the carbon black is a coloring pigment and plays a role in coloring.

Based on the mass fraction of the JT-WBE522 waterborne epoxy emulsion, the component A of the present invention includes 0.2 to 0.5 parts of silane coupling agent, preferably 0.3 to 0.4 parts. The silane coupling agent of the present invention is preferably MP-200 silane coupling agent. The present invention preferably uses the above-mentioned type of silane coupling agent, which can improve the adhesion between the paint film and the substrate, and is beneficial to improve the water resistance and salt spray resistance of the coating.

Based on the mass fraction of the JT-WBE522 waterborne epoxy emulsion, the component A of the present invention includes 0.5 to 1 part of an anti-flash rust additive, preferably 0.5 to 0.8 part, and more preferably 0.5 to 0.6 part. The anti-flash rust additive of the present invention is preferably Raybo 60 anti-flash rust additive.

Based on the mass fraction of the JT-WBE522 water-based epoxy emulsion, the component A of the present invention includes 0.2 to 0.5 parts of thickener, preferably 0.2 to 0.3 parts. The thickener of the present invention is preferably 0620 thickener. The present invention preferably uses the above-mentioned thickener, which is beneficial to increase viscosity, prevent sedimentation, and prevent sagging during construction, which is beneficial to increase the thickness of the paint film.

Based on the mass fraction of the JT-WBE522 waterborne epoxy emulsion, the component A of the present invention includes 0.1 to 0.3 parts of a wetting agent, preferably 0.1 to 0.2 parts. The wetting agent of the present invention is preferably a 4100 wetting agent. The present invention preferably uses the above-mentioned types of wetting agents, which can reduce the surface tension of the paint film and help reduce the drawbacks of shrinkage cavities of the paint film.

Based on the mass fraction of the JT-WBE522 waterborne epoxy emulsion, the component A of the present invention includes 3 to 10 parts of a cosolvent, preferably 5 to 10 parts, and more preferably 8 to 10 parts. The cosolvent of the present invention is preferably dipropylene glycol butyl ether (DPNB) and/or dipropylene glycol methyl ether (DPM), more preferably dipropylene glycol butyl ether and dipropylene glycol methyl ether, and the mass ratio of dipropylene glycol butyl ether to dipropylene glycol methyl ether is preferably 6:3.5 to 4.5, more preferably 6:4. The present invention preferably uses the above-mentioned type of cosolvent, which can make the paint film form better, which is beneficial to improve the salt spray resistance of the paint film.

Based on the mass fraction of the JT-WBE522 waterborne epoxy emulsion, the component A of the present invention includes 10 to 20 parts of water, preferably 14 to 17 parts, and more preferably 15 to 16.5 parts. The water of the present invention is preferably deionized water.

In the present invention, the fineness of the component A is preferably ≤30 μm, and the solid content is preferably ≥46 wt %.

The ultra-long active period two-component epoxy primer of the present invention is specifically a gray primer.

The present invention provides a method for preparing the ultra-long active period two-component epoxy primer according to the above technical solution, comprising the following steps:

Mix water, dispersant, mica powder, titanium dioxide, wollastonite, talc, carbon black and part of the defoamer and grind them to obtain a grinding slurry; mix the grinding slurry, JT-WBE522 water-based epoxy emulsion, cosolvent, thickener, wetting agent, silane coupling agent, anti-flash rust additive and the remaining defoamer to obtain the A component;

The 3986 curing agent, propylene glycol methyl ether and water are mixed to obtain the B component.

The present invention mixes water, dispersant, mica powder, titanium dioxide, wollastonite, talc, carbon black and part of the defoamer and grinds them to obtain a grinding slurry. In the present invention, the part of the defoamer is preferably 30-35% of the total mass of the defoamer. The present invention preferably mixes dispersant, mica powder, titanium dioxide, wollastonite, talc, carbon black, part of the water and part of the defoamer and grinds them, then uses the remaining water to grind, and uses the ground and washed materials as grinding slurry for subsequent treatment. In the present invention, the part of the water is preferably 85-95% of the total mass of the water, and more preferably 88-91%. The present invention preferably adds dispersant and part of defoamer to the water in sequence under the condition of stirring speed of 300-500rpm (preferably 400rpm), then increases stirring speed to 500-700rpm (preferably 600rpm), adds mica powder, titanium dioxide, wollastonite, talcum powder and carbon black in sequence, stirs for 3-5min (preferably 4min) after adding each reagent, and then adds the next reagent, stirs for 15-25min (preferably 20min) after the last reagent is added, and then places the obtained slurry in a grinder for grinding. In the present invention, the grinding process preferably controls the grinding temperature ≤50°C and the grinding pressure ≤0.2MPa, samples are taken for detection every 20min, and grinding is terminated when the fineness is ≤20μm, the obtained slurry is put into a blending cylinder, and the remaining water is used for grinding, the obtained grinding slurry is put into the blending cylinder, and subsequent treatment is carried out in the blending cylinder.

After obtaining the grinding slurry, the present invention mixes the grinding slurry, JT-WBE522 water-based epoxy emulsion, cosolvent, thickener, wetting agent, silane coupling agent, anti-flash rust aid and remaining defoamer to obtain the A component. The present invention preferably adds JT-WBE522 water-based epoxy emulsion to the grinding slurry, stirs for 5 to 15 minutes (preferably 10 minutes) at 400 to 500 rm (preferably 450 rpm), and then sequentially adds the remaining defoamer, all wetting agents, all cosolvents, all thickeners, all silane coupling agents and all anti-flash rust aids, stirs for 3 to 5 minutes (preferably 4 minutes) after each reagent is added, and then adds the next reagent, stirs for 10 to 20 minutes (preferably 15 minutes) after the last reagent is added, and then filtered through a 100-mesh filter to obtain the A component.

The present invention mixes 3986 curing agent, propylene glycol methyl ether and water to obtain the B component. The present invention preferably adds propylene glycol methyl ether and 3986 curing agent to the water in sequence under the condition of a stirring rate of 350 to 450 rpm (preferably 400 rpm), stirs for 3 to 5 minutes (preferably 4 minutes) after adding each reagent, and then adds the next reagent, stirs for 15 to 25 minutes (preferably 20 minutes) after the last reagent is added, and then filters through a 100-mesh filter to obtain the B component.

The present invention provides the use of the ultra-long activation period two-component epoxy primer described in the above technical solution or the ultra-long activation period two-component epoxy primer prepared by the preparation method described in the above technical solution in transformer spray coating.

The technical solutions in the present invention will be described clearly and completely below in conjunction with the embodiments of the present invention. Obviously, the described embodiments are only a part of the embodiments of the present invention, not all of them. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without creative work are within the scope of protection of the present invention.

The sources of the reagents used in the following examples are shown in Table 1:

Table 1 Sources of reagents used in the examples

Reagent Type Indicator parameters source JTWBE522 epoxy emulsion / Jutu Technology (Dongguan) Co., Ltd. BYK190 dispersant / BYK Chemical Co., Ltd. BYK-028 defoamer / BYK Chemical Co., Ltd. R996 Rutile Titanium Dioxide Particle size: 0.1～0.45μm Beijing Yantai North Chemical Co., Ltd. GA-4 Mica Powder Particle size is 5-10 μm Anhui Grey New Material Technology Co., Ltd. MA-100 Carbon Black Particle size: 10～100μm Mitsubishi Chemical Corporation talcum powder 1250 mesh Haicheng Pinyang Talc Mining Co., Ltd. Wollastonite 1250 mesh Lingshou County Shifeng Mining Processing Plant 4100 Wetting Agent / Guangzhou Digao Building Materials Co., Ltd. 0620 Thickener / Detian Technology Development (Shanghai) Co., Ltd. MP-200 silane coupling agent / Guangzhou Yinuo Chemical Technology Co., Ltd. Raybo60 anti-flash rust additive / Guangzhou Chenhui Trading Co., Ltd. 3986 curing agent / Dongguan Shuangling New Materials Co., Ltd.

Embodiments 1 to 5

The formula of the two-component epoxy primer in Examples 1 to 5 is shown in Table 2, and the preparation method is as follows:

Under the condition of stirring speed of 400rpm, dispersant (denoted as 2#) and part of defoamer (denoted as 3#) were added to part of deionized water (denoted as 1#) in sequence, and the stirring speed was increased to 600rpm. Mica powder (denoted as 4#), titanium dioxide (denoted as 5#), wollastonite (denoted as 6#), talcum powder (denoted as 7#) and carbon black (denoted as 8#) were added in sequence. After adding each reagent, the mixture was stirred for 4min before adding the next reagent. After the last reagent was added, the mixture was stirred for 20min to obtain the pre-training slurry.

The pre-refined slurry is placed in a grinder for grinding, the grinding temperature is controlled to be less than 50°C and the grinding pressure is less than 0.2MPa, sampling is performed every 20 minutes, and grinding is completed when the fineness is ≤20μm. The obtained slurry is put into a blending tank, and the remaining deionized water (recorded as 9#) is used for grinding, and the obtained ground slurry is put into the blending tank;

Add JTWBE522 epoxy emulsion (recorded as 10#) to the blending cylinder, stir at 450rpm for 10min, then add the remaining defoamer (recorded as 11#), all wetting agents (recorded as 12#), all cosolvents DPNB (recorded as 13#), all cosolvents DPM (recorded as 14#), all thickeners (recorded as 15#), all silane coupling agents (recorded as 16#) and all anti-flash rust additives (recorded as 17#) in sequence, stir for 4min after adding each reagent and then add the next reagent, stir for 15min after adding the last reagent, and then filter through a 100-mesh filter to obtain component A (quality control items: appearance requires uniform surface color without particles; solid content ≥46wt%; fineness ≤30μm);

Under the condition of stirring speed of 400rpm, according to the mass ratio of 3986 curing agent, propylene glycol methyl ether (PM) and deionized water of 20:5:20, propylene glycol methyl ether and 3986 curing agent were added to deionized water in sequence. After adding each reagent, stir for 4min before adding the next reagent. After adding the last reagent, stir for 20min, and then filter through a 100-mesh filter to obtain component B (quality control items: appearance requires uniform surface color and no particles; solid content ≥20wt%).

Table 2 Formulation of two-component epoxy primer in Examples 1 to 5

Comparative Examples 1 to 5

The formula of the two-component epoxy primer in Comparative Examples 1 to 5 is shown in Table 3. The preparation method is similar to that in Example 1, the main difference being that the "JTWBE522 epoxy emulsion" in Example 1 is replaced by "United Curing Science 2092 epoxy emulsion".

Table 3 Formula of two-component epoxy primer in Comparative Examples 1 to 5

Test Example 1

The activation period and salt spray resistance of the two-component epoxy primers prepared in each embodiment and comparative example were tested, wherein the activation period was determined based on the viscosity change of the two-component epoxy primer and the change in the performance of the paint film (specifically, when the viscosity of the two-component epoxy primer doubles and the acid resistance, alkali resistance, adhesion, bending, impact, gloss and salt spray resistance of the paint film decrease, it is judged that the activation period has been reached), and the salt spray resistance was tested according to the GB/T 1771-2007 method, and the results are shown in Table 4. As can be seen from Table 4, the activation period of the two-component epoxy primers in Examples 1 to 5 is long, and the salt spray resistance can meet the requirements. Considering the cost-effectiveness, the two-component epoxy primer in Example 2 is the best formula. Although the salt spray resistance of the two-component epoxy primers in each comparative example can basically meet the requirements, the activation period is significantly lower than that of the corresponding embodiment.

Table 4 Performance test data of two-component epoxy primer in each embodiment and comparative example

Sample source Active Period Salt spray resistance Example 1 24h 500h Example 2 24h 800h Example 3 24h 600h Example 4 24h 600h Example 5 24h 500h Comparative Example 1 12h 500h Comparative Example 2 12h 500h Comparative Example 3 13h 600h Comparative Example 4 12h 500h Comparative Example 5 12h 500h

The above is only a preferred embodiment of the present invention. It should be pointed out that for ordinary technicians in this technical field, several improvements and modifications can be made without departing from the principle of the present invention. These improvements and modifications should also be regarded as the scope of protection of the present invention.

Claims (10)

1. A two-component epoxy primer with an ultra-long pot life, characterized in that it comprises a component A and a component B which are packaged separately; the mass ratio of the component A to the component B is 1.5 to 2.5:1; The B component includes 3986 curing agent, propylene glycol methyl ether and water; The component A includes the following components in parts by mass: 35 to 55 parts of JT-WBE522 water-based epoxy emulsion; 1 to 3 parts of dispersant; 0.3 to 0.5 parts of defoamer; 5 to 10 parts of titanium dioxide; 5 to 15 parts of mica powder; 10 to 15 parts of wollastonite; 5 to 10 parts of talc; 0.1 to 0.5 parts of carbon black; 0.2 to 0.5 parts of silane coupling agent; 0.5 to 1 parts of anti-flash rust additive; 0.2 to 0.5 parts of thickener; 0.1 to 0.3 parts of wetting agent; 3 to 10 parts of cosolvent; and 10 to 20 parts of water. 2. The ultra-long pot life two-component epoxy primer according to claim 1, characterized in that the mass ratio of 3986 curing agent, propylene glycol methyl ether and water in component B is 20:4-6:18-22. 3. The ultra-long pot life two-component epoxy primer according to claim 1 or 2, characterized in that the dispersant is BYK190 dispersant and the defoamer is BYK-028 defoamer. 4. The ultra-long pot life two-component epoxy primer according to claim 1 or 2, characterized in that the titanium dioxide is R996 rutile titanium dioxide; the mica powder is GA-4 mica powder; and the carbon black is MA-100 carbon black. 5. The ultra-long pot life two-component epoxy primer according to claim 1 or 2, characterized in that the silane coupling agent is MP-200 silane coupling agent; and the anti-flash rust additive is Raybo 60 anti-flash rust additive. 6. The ultra-long pot life two-component epoxy primer according to claim 1 or 2, characterized in that the thickener is 0620 thickener; the wetting agent is 4100 wetting agent; and the cosolvent is dipropylene glycol butyl ether and/or dipropylene glycol methyl ether. 7. The ultra-long pot life two-component epoxy primer according to claim 1 or 2, characterized in that the fineness of component A is ≤30 μm and the solid content is ≥46 wt%; the solid content of component B is ≥20 wt%. 8. The method for preparing the ultra-long pot life two-component epoxy primer according to any one of claims 1 to 7, characterized in that it comprises the following steps: Mix water, dispersant, mica powder, titanium dioxide, wollastonite, talc, carbon black and part of the defoamer and grind them to obtain a grinding slurry; mix the grinding slurry, JT-WBE522 water-based epoxy emulsion, cosolvent, thickener, wetting agent, silane coupling agent, anti-flash rust additive and the remaining defoamer to obtain the A component; The 3986 curing agent, propylene glycol methyl ether and water are mixed to obtain the B component. 9 . The preparation method according to claim 8 , characterized in that the grinding temperature is ≤50° C., the pressure is ≤0.2 MPa; and the fineness of the grinding slurry is ≤20 μm. 10. Use of the ultra-long active period two-component epoxy primer according to any one of claims 1 to 7 or the ultra-long active period two-component epoxy primer prepared by the preparation method according to claim 8 or 9 in transformer coating.