A water-based two-component epoxy primer for rail transit coating and preparation method thereof

Abstract

The present invention relates to a water-based two-component epoxy primer for rail transit coating and a preparation method thereof, wherein the epoxy primer is composed of component A and component B, wherein component A includes a water-based epoxy resin dispersion, a cosolvent, a dispersant, a wetting agent, ultrafine barium sulfate, titanium dioxide, ultrafine talcum powder, an anti-rust pigment, a defoamer, a rheological agent, carbon black, an anti-sagging agent and deionized water; and component B includes ethylene glycol monobutyl ether, a modified amine curing agent, an anti-flash rust agent and deionized water. The epoxy primer of the present invention has excellent adhesion to aluminum, the composite layer paint film has good adhesion, good anti-sagging performance, a wet film spraying can be μm ≥ 135 μm, the corresponding dry film thickness ≥ 55 μm, can adapt to electrostatic spraying, and has high construction efficiency. At the same time, the salt spray resistance (steel plate) of the primer reaches 720h and above, the butanone wiping resistance is excellent, and it has good anti-rust and corrosion resistance, and can be widely used in large rail transit vehicles.

Description

Technical Field

[0001] The invention belongs to the technical field of coatings, and in particular relates to a water-based two-component epoxy primer for rail transit coating and a preparation method thereof. Background Art

[0002] In recent years, as the environmental protection process of vehicle painting in the rail transit industry continues to accelerate, in order to further match the environmental protection performance requirements of rail transit vehicles, water-based coatings for vehicle painting construction have developed rapidly. Currently, they mainly include water-based epoxy primers, water-based polyurethane epoxy primers, color paints and varnishes. Due to the special operating environment of rail transit, the paint film of its vehicle painting needs to have extremely high mechanical properties, anti-corrosion properties and spray construction performance, but the current water-based primers are difficult to achieve excellent sprayability and functionality at the same time. The epoxy primers disclosed in CN111117426A and CN105949943A have fast surface drying speed, good mechanical properties, and excellent anti-corrosion properties. In particular, the neutral salt spray resistance of CN105949943A is as high as 900h, but the sprayability is insufficient and the anti-sagging performance is poor. The thickness of a wet film is usually less than 120μm, which has a certain impact on the spraying time, construction efficiency, and number of constructions during the construction process. A water-based epoxy anti-corrosion primer disclosed in CN117210090A has excellent sprayability and an anti-sagging film thickness of up to 200μm, but its anti-corrosion performance is extremely poor, and the salt spray resistance is only 300h. It is difficult to achieve long-term operation in vehicle painting in the rail transit industry, is easily damaged, and requires timely recoating, which is costly and difficult to be widely used.

[0003] Therefore, in summary, there is still a need to develop and research environmentally friendly water-based epoxy primers that have excellent spray construction performance and comprehensive anti-corrosion and mechanical properties. Summary of the invention

[0004] In view of the problems existing in the prior art, the present invention provides a water-based two-component epoxy primer for rail transit coating and a preparation method thereof. The water-based two-component epoxy primer prepared by the present invention is used on large rail transit vehicles, has high gloss, good anti-sagging property, excellent construction performance, can be adapted to electrostatic spraying, has high construction efficiency, excellent polishability, strong filling power on elastic putty, and the composite layer paint film has good adhesion.

[0005] In a first aspect, the present invention provides a water-based two-component epoxy primer for rail transit coating, wherein the epoxy primer consists of component A and component B.

[0006] Further, the component A comprises, by weight, 25 to 50 parts of aqueous epoxy resin dispersion, 1 to 5 parts of cosolvent, 0.3 to 2.0 parts of dispersant, 0.1 to 1.0 parts of wetting agent, 10 to 22 parts of superfine barium sulfate, 10 to 20 parts of titanium dioxide, 5 to 20 parts of superfine talc, 2 to 8 parts of anti-rust pigment, 0.2 to 1.0 parts of defoamer, 0.2 to 1.0 parts of rheological agent, 0.1 to 5.0 parts of carbon black, 0.1 to 2.0 parts of anti-sagging agent and 10 to 25 parts of deionized water;

[0007] The component B comprises 20 to 35 parts of ethylene glycol monobutyl ether, 40 to 60 parts of modified amine curing agent, 2 to 5 parts of anti-flash rust agent and 20 to 35 parts of deionized water.

[0008] Furthermore, the waterborne epoxy resin dispersion in component A is selected from Tongde 3EE102W, Tongde 3EE104W, Allnex BECKOPOX TM One or more of EP 384w / 53WAMP, LianGu Banco 2095;

[0009] Preferably, the aqueous epoxy resin dispersion contains BECKOPOX TM The mass ratio of EP 384w / 53WAMP, Lian Gu Banco2095, and Tongde 3EE102W is (2~5):1:(0~0.5).

[0010] Further, the dispersant is Digo 755W and / or Hemmings FX600;

[0011] The wetting agent is Digo 4100 and / or Air Chemical SURFYNOL 104BC;

[0012] Preferably, the mass ratio of Digo 4100 to Air Chemicals SURFYNOL 104BC in the wetting agent is 1:1-5.

[0013] Furthermore, the anti-rust pigment is selected from any one or more of REALCARE WS10ES of Huagao Ke, APW-Ⅱ of Guangxi Xinjing, zinc phosphate, Aolin 908-I ultrafine ferrophosphorus anti-rust powder, Aolin 908-II ultrafine ferrophosphorus anti-rust powder, and PZS-II ultrafine ferrophosphorus zinc silicon powder;

[0014] Preferably, the mass ratio of the ultrafine phosphorus iron zinc silicon powder of Huagao Ke REALCARE WS10ES, Guangxi Xinjing APW-Ⅱ, and PZS-II is 3:1 to 3:1.

[0015] Furthermore, the defoaming agent is Digo 902w and / or BASF Foamstar ST2437;

[0016] Further, the rheological agent is a mixture of Evonik AEROSIL 200 and / or Evonik AEROSIL 380 and Hemmings LT;

[0017] Preferably, the mass ratio of Evonik AEROSIL 200 and / or Evonik AEROSIL 380 to Hemmings LT in the rheological agent is 1:4-7.

[0018] Furthermore, the ultrafine barium sulfate is 1250 mesh, and the ultrafine talc is 1250 mesh.

[0019] Furthermore, the co-solvent is selected from any one or more of ethylene glycol monobutyl ether, propylene glycol methyl ether, diethylene glycol butyl ether, and dipropylene glycol butyl ether.

[0020] Furthermore, the anti-sagging agent is selected from Two or more of Gel 0620, Digo 3060, and Hemmings 105A;

[0021] Preferably, the anti-sagging agent is in a mass ratio of 3-5:1-2:1-2 A mixture of Gel 0620, Digo 3060, and Hemmings 105A.

[0022] Furthermore, the modified amine curing agent in the B component comprises a modified amine curing agent I and a modified amine curing agent II, wherein the modified amine curing agent I is selected from Huntsman 3986 and / or Huntsman Aradur38-1, modified amine curing agent II is selected from Qirun EH 3504;

[0023] Preferably, the mass ratio of the modified amine curing agent I to the modified amine curing agent II is 1:2-5.

[0024] Furthermore, the flash rust inhibitor is selected from one or more of Raybo 60, FA179, and ASCOTRAN-H10.

[0025] Furthermore, the mass ratio of component A to component B is 5 to 7:1.

[0026] In a second aspect, the present invention provides a method for preparing a water-based two-component epoxy primer for rail transit coating, which specifically comprises the following steps:

[0027] Preparation of component A:

[0028] S1. Mix the dispersant, wetting agent, defoamer, rheological agent and deionized water in the formula, stir at 200-300 r / min for 5-30 min, add ultrafine barium sulfate, titanium dioxide, ultrafine talcum powder, carbon black and anti-rust pigment, stir at 500-800 r / min for 30-60 min, and then sand grind to obtain a water-based primer slurry;

[0029] S2. Add the water-based primer slurry and the cosolvent prepared in step S1 to the water-based epoxy resin dispersion at a stirring speed of 200 to 300 r / min, and continue stirring for 20 to 30 minutes;

[0030] S3, adding an anti-sagging agent to step S2, stirring at 300-600 r / min for 20-40 min to obtain component A;

[0031] Preparation of component B:

[0032] Component B is prepared by mixing ethylene glycol monobutyl ether, modified amine curing agent, anti-flash rust agent and deionized water.

[0033] Furthermore, during the construction process, component A, component B and additional deionized water are mixed, and the mass ratio of component A, component B and additional deionized water is 6:1:0.1-0.6.

[0034] The waterborne two-component epoxy primer of the present invention uses multiple waterborne epoxy resin dispersions for composite use, has excellent adhesion, and has good salt spray resistance when matched with specific anti-rust pigments, especially when using BECKOPOX TM EP 384w / 53WAMP and LianGu Banco 2095 can achieve excellent salt spray resistance for 744 hours within a certain proportion range, and can ensure the corrosion resistance of the paint film when used in rail transit coating.

[0035] The waterborne two-component epoxy primer of the present invention uses a specific rheological agent and an anti-sagging agent in combination to achieve an excellent anti-sagging effect. Since the waterborne two-component epoxy primer of the present invention contains a large amount of powder and particles, the composite rheological agent of Evonik AEROSIL 380 and Hemmings LT is used to form a unique stable structure in the system, which can effectively improve the properties of the powder, improve the fluidity and anti-caking properties, protect the dispersed particles in the system, help control sagging, significantly improve the spraying performance of the primer, form a thick paste coating, maintain excellent leveling, prevent particle sedimentation and provide sufficient dry film thickness, so that the primer has better coating performance and stability. The composite anti-sagging agent of Gel 0620, Digo 3060 and Hemmings 105A can significantly increase the thickness of the vertical surface and effectively prevent sagging. Therefore, the present invention adopts a specific rheological agent and an anti-sagging agent to make the prepared water-based two-component epoxy primer wet film sprayed in one time μm ≥ 135μm, and the corresponding dry film thickness ≥ 55μm, which has excellent anti-sagging and good spraying performance.

[0036] In addition, the water-based two-component epoxy primer for rail transit coating of the present invention also uses a wetting agent compounded with Digo 4100 and Air Chemical SURFYNOL 104BC. Since the water-based two-component epoxy primer for rail transit coating of the present invention contains a large amount of pigment and filler particles, it is necessary to wet the mixture well to ensure better wetting of the material and particle surface, change the adsorption performance between the components in the mixture, and improve the compatibility of the mixture and the compatibility of the system. At the same time, the mixture of Digo 4100 and Air Chemical SURFYNOL 104BC can significantly improve the shrinkage effect and effectively reduce the surface tension, thereby improving the fluidity of the system and making the system more stable. The defoamer in the water-based two-component epoxy primer for rail transit coating of the present invention also uses BASF 2437, which has a faster ability to break bubbles and microbubbles, and improves the compatibility of the mixture and the compatibility of the system.

[0037] Compared with the prior art, the present invention has the following beneficial effects:

[0038] The water-based two-component epoxy primer for rail transit coating of the present invention has excellent anti-sagging performance, can adapt to electrostatic spraying, and can spray the wet film in one step to 135 μm or more, and the corresponding dry film thickness is 55 μm or more. The construction efficiency is high, and the aluminum material has excellent adhesion. The composite layer paint film has good adhesion, all within the range of 0-1 level, and has excellent impact resistance of up to 50 cm, bending performance of ≤2 mm, and good mechanical properties. At the same time, the salt spray resistance (steel plate) of the primer reaches 720 hours or more, and the butanone wiping resistance is excellent. It has good anti-rust and corrosion resistance and can be widely used in large rail transit vehicles. DETAILED DESCRIPTION

[0039] The experimental methods in the following examples of the present invention, where no specific conditions are specified, are usually carried out under conventional conditions or under conditions recommended by the manufacturers. The various commonly used chemical reagents used in the examples are all commercially available products.

[0040] Unless otherwise defined, all technical and scientific terms used in the present invention have the same meaning as those commonly understood by those skilled in the art of the present invention. The terms used in the specification of the present invention are only for the purpose of describing specific embodiments and are not intended to limit the present invention.

[0041] In order to make the purpose, technical scheme and advantages of the present invention clearer, the present invention is further described in detail below in conjunction with specific embodiments. It should be understood that these descriptions are exemplary only and are not intended to limit the scope of the present invention. In addition, in the following description, the description of known structures and technologies is omitted to avoid unnecessary confusion of the concept of the present invention.

[0042] The present invention is further described in the following examples, but the examples are not intended to limit the scope of protection of the present invention.

[0043] Example 1

[0044] The water-based two-component epoxy primer for rail transit coating in this embodiment has a specific raw material formula as shown in Table 1;

[0045] Table 1:

[0046]

[0047]

[0048] According to the composition formula in Table 1, the preparation steps of the water-based two-component epoxy primer for rail transit coating of the present invention are as follows:

[0049] Preparation of component A:

[0050] S1. Mix the formulated amount of dispersant, wetting agent (Digo 4100, Air Chemical SURFYNOL 104BC), defoamer, rheological agent (Evonik AEROSIL 380, Hemmings LT) and deionized water, stir at 300 r / min for 5 min, add the formulated amount of ultrafine barium sulfate, titanium dioxide, ultrafine talc, carbon black and anti-rust pigment (with Huagao Ke REALCARE WS10ES, Guangxi Xinjing APW-Ⅱ, PZS-II ultrafine phosphorus iron zinc silicon powder), stir at 800 r / min for 30 min, and then sand grind to a fineness of less than 20 μm to prepare a water-based primer slurry;

[0051] S2, at a stirring speed of 300r / min, add the formulated amount of waterborne epoxy resin dispersion (BECKOPOX TM EP 384w / 53WAMP, Liangu Banco 2095) were added with the water-based primer slurry prepared in step S1 and BCS, and stirring was continued for 20 minutes;

[0052] S3, adding anti-sagging agent ( Gel 0620, Digo 3060, Hemmings 105A), stirred at 350r / min for 30min to obtain component A;

[0053] Preparation of component B:

[0054] BCS, modified amine curing agent I, modified amine curing agent II, anti-flash rust agent and deionized water were added into an empty container and mixed to prepare component B.

[0055] During the construction process, mix component A, component B and deionized water in a mass ratio of 6:1:0.5.

[0056] Example 2

[0057] The water-based two-component epoxy primer for rail transit coating in this embodiment has a specific composition formula as shown in Table 2;

[0058] Table 2:

[0059]

[0060]

[0061] According to the composition formula in Table 2, the preparation steps of the water-based two-component epoxy primer for rail transit coating of the present invention are as follows:

[0062] Preparation of component A:

[0063] S1. Mix the dispersant, wetting agent (Digo 4100, Air Chemical SURFYNOL 104BC), defoamer, rheological agent (Evonik AEROSIL 380, Hemmings LT) and deionized water in the formula, stir at 300 r / min for 5 min, add ultrafine barium sulfate, titanium dioxide, ultrafine talc, carbon black and anti-rust pigment (with Huagao Technology REALCARE WS10ES, Guangxi Xinjing APW-Ⅱ, PZS-II ultrafine phosphorus iron zinc silicon powder), stir at 800 r / min for 30 min, and then sand grind to a fineness of less than 20 μm to prepare a water-based primer slurry;

[0064] S2, at a stirring speed of 300r / min, add the formulated amount of waterborne epoxy resin dispersion (BECKOPOX TM EP 384w / 53WAMP, Liangu Banco 2095) were added with the water-based primer slurry prepared in step S1 and BCS, and stirring was continued for 20 minutes;

[0065] S3, adding anti-sagging agent ( Gel 0620, Digo 3060, Hemmings 105A), stirred at 350r / min for 30min to obtain component A;

[0066] Preparation of component B:

[0067] BCS, modified amine curing agent I, modified amine curing agent II, anti-flash rust agent and deionized water were added into an empty container and mixed to prepare component B.

[0068] During the construction process, mix component A, component B and deionized water in a mass ratio of 6:1:0.5.

[0069] Example 3

[0070] The water-based two-component epoxy primer for rail transit coating in this embodiment has a specific composition formula as shown in Table 3;

[0071] Table 3:

[0072]

[0073]

[0074] According to the composition formula in Table 3, the preparation steps of the water-based two-component epoxy primer for rail transit coating of the present invention are as follows:

[0075] Preparation of component A:

[0076] S1. Mix the dispersant, wetting agent (Digo 4100, Air Chemical SURFYNOL 104BC), defoamer, rheological agent (Evonik AEROSIL 380, Hemmings LT) and deionized water in the formula, stir at 300 r / min for 5 min, add ultrafine barium sulfate, titanium dioxide, ultrafine talc, carbon black and anti-rust pigment (with Huagao Technology REALCARE WS10ES, Guangxi Xinjing APW-Ⅱ, PZS-II ultrafine phosphorus iron zinc silicon powder), stir at 800 r / min for 30 min, and then sand grind to a fineness of less than 20 μm to prepare a water-based primer slurry;

[0077] S2, at a stirring speed of 300r / min, add the formulated amount of waterborne epoxy resin dispersion (BECKOPOX TM EP 384w / 53WAMP, Liangu Banco 2095) were added with the water-based primer slurry prepared in step S1 and BCS, and stirring was continued for 20 minutes;

[0078] S3, adding anti-sagging agent ( Gel 0620, Digo 3060, Hemmings 105A), stirred at 350r / min for 30min to obtain component A;

[0079] Preparation of component B:

[0080] BCS, modified amine curing agent I, modified amine curing agent II, anti-flash rust agent and deionized water were added into an empty container and mixed to prepare component B.

[0081] During the construction process, mix component A, component B and deionized water in a mass ratio of 6:1:0.5.

[0082] Example 4

[0083] The water-based two-component epoxy primer for rail transit coating in this embodiment has a specific composition formula as shown in Table 4;

[0084] Table 4:

[0085]

[0086]

[0087] According to the composition formula in Table 4, the preparation steps of the water-based two-component epoxy primer for rail transit coating of the present invention are as follows:

[0088] Preparation of component A:

[0089] S1. Mix the dispersant, wetting agent (Digo 4100, Air Chemical SURFYNOL 104BC), defoamer, rheological agent (Evonik AEROSIL 380, Hemmings LT) and deionized water in the formula, stir at 300 r / min for 5 min, add ultrafine barium sulfate, titanium dioxide, ultrafine talc, carbon black and anti-rust pigment (with Huagao Technology REALCARE WS10ES, Guangxi Xinjing APW-Ⅱ, PZS-II ultrafine phosphorus iron zinc silicon powder), stir at 800 r / min for 30 min, and then sand grind to a fineness of less than 20 μm to prepare a water-based primer slurry;

[0090] S2, at a stirring speed of 300r / min, add the formulated amount of waterborne epoxy resin dispersion (BECKOPOX TM Add the water-based primer slurry prepared in step S1 and BCS into EP 384w / 53WAMP, Liangu Banco 2095, Tongde 3EE102W), and continue stirring for 20 minutes;

[0091] S3, adding anti-sagging agent ( Gel 0620, Digo 3060, Hemmings 105A), stirred at 350r / min for 30min to obtain component A;

[0092] Preparation of component B:

[0093] BCS, modified amine curing agent I, modified amine curing agent II, anti-flash rust agent and deionized water were added into an empty container and mixed to prepare component B.

[0094] During the construction process, mix component A, component B and deionized water in a mass ratio of 6:1:0.5.

[0095] Test Example 1: Performance test of water-based two-component epoxy primer for rail transit coating prepared in Examples 1 to 4

[0096] Part I. Test Methods

[0097] The performance test method of the water-based two-component epoxy primer for rail transit coating prepared by the present invention is specifically shown in Table 5;

[0098] Table 5 Performance test methods

[0099]

[0100] Part II: Test Results

[0101] According to the detection method given in Table 5 of the first part, the performance of the water-based two-component epoxy primer for rail transit coating prepared in Examples 1 to 4 of the present invention was tested, and the specific test results are shown in Table 6;

[0102] Table 6 Performance test results of water-based two-component epoxy primer for rail transit coating in Examples 1 to 4

[0103]

[0104]

[0105] It can be seen from the results in Table 6 that the water-based two-component epoxy primer for rail transit coating prepared in Examples 1 to 4 of the present invention has good single-layer adhesion and composite layer adhesion, both within the range of 0-1, good impact resistance up to 50cm, bending performance ≤2mm, and good solvent resistance wiping test. The wet film of the water-based two-component epoxy primer can be sprayed in one μm ≥135μm, and the corresponding dry film thickness is ≥55μm. It has excellent anti-sagging properties, salt spray resistance (steel plate) ≥720h, and has good anti-rust and corrosion properties.

[0106] Comparative Example 1

[0107] The difference between the formulation of this comparative example and Example 1 is that the components of the waterborne epoxy resin dispersion are different. In this comparative example, the waterborne two-component epoxy primer does not contain Banco 2095, but uses BECKOPOX TM EP 384w / 53WAMP was used to make up the mass, and the other ingredients and preparation method were consistent with those in Example 1.

[0108] Comparative Example 2

[0109] The difference between the formulation of this comparative example and Example 1 is that the components of the waterborne epoxy resin dispersion are different. The waterborne two-component epoxy primer in this comparative example is BECKOPOX TM The addition amount of EP 384w / 53WAMP is 40kg, the addition amount of Liangu Banco2095 is 5kg, and the other ingredients and preparation method are consistent with those in Example 1.

[0110] Comparative Example 3

[0111] The difference between the formula composition of this comparative example and Example 1 lies in the total content of rheological agent and anti-sagging agent. The total amount of rheological agent added in the water-based two-component epoxy primer of this comparative example is 1.2 kg, and the total amount of anti-sagging agent added is 0.1 kg. The remaining ingredients, proportions and preparation methods are consistent with those of Example 1.

[0112] Comparative Example 4

[0113] The difference between the formula composition of this comparative example and that of Example 1 is that the proportion of the anti-sagging agent is different. The anti-sagging agent is not added to the water-based two-component epoxy primer of this comparative example. Gel 0620, the addition amount of Digo 3060 is 0.5kg, the addition amount of Hemmings 105A is 0.5kg, and the other ingredients, proportions and preparation methods are consistent with those in Example 1.

[0114] Comparative Example 5

[0115] The difference between the formula composition of this comparative example and that of Example 1 is that the proportion of the anti-sagging agent component is different. The anti-sagging agent in the water-based two-component epoxy primer of this comparative example does not include Digo 3060 and Hemmings 105A. The addition amount of Gel 0620 is 1.0 kg, and the other ingredients, proportions and preparation methods are consistent with those in Example 1.

[0116] Comparative Example 6

[0117] The difference between the formula composition of this comparative example and Example 1 is that the modified amine curing agent component in component B is different. No modified amine curing agent II is added to component B of the water-based two-component epoxy primer of this comparative example, and modified amine curing agent I is used to make up the mass. The remaining components, proportions and preparation methods are consistent with those of Example 1.

[0118] Comparative Example 7

[0119] The difference between the formula composition of this comparative example and Example 1 is that the modified amine curing agent component in component B is different. The modified amine curing agent II (Qirun EH 3504) in component B of the water-based two-component epoxy primer of this comparative example is replaced by Qirun EH 3503, and the remaining components, proportions and preparation methods are consistent with those in Example 1.

[0120] Test Example 2: Performance test of water-based two-component epoxy primer for rail transit coating prepared in Comparative Examples 1 to 7

[0121] This test example tests the performance of the water-based two-component epoxy primer for rail transit coating prepared in Comparative Examples 1 to 7. The test method is consistent with that of Test Example 1. The test results are shown in Table 7.

[0122] Table 7: Performance test results of water-based two-component epoxy primers for rail transit coatings in Comparative Examples 1 to 7

[0123]

[0124] Comparing the results of Table 6 and Table 7, it can be seen that the water-based two-component epoxy primers for rail transit coating prepared in Examples 1 to 4 of the present invention have excellent comprehensive properties, while the water-based two-component epoxy primers for rail transit coating prepared in Comparative Examples 1 to 7 have a certain degree of decline in some performances. It can be seen from Comparative Examples 1 to 2 that the composition and content of the water-based epoxy resin dispersion greatly affect the sharp decline in the mechanical properties, adhesion, solvent resistance, anti-sagging and corrosion resistance of the epoxy primer, and the rheological agent and the anti-sagging agent jointly affect the wet film anti-sagging performance of the epoxy primer, wherein the anti-sagging agent Gel0620 has a great influence on the performance. Its content in Comparative Examples 3 to 5 significantly affects the spraying performance and film performance of the primer. In addition, it can be seen from Comparative Examples 6 to 7 that adding Qirun EH 3504 to the composite modified amine curing system used in the present invention can effectively improve the adhesion and corrosion resistance of the paint film. Therefore, it can be seen that the excellent performance of the water-based two-component epoxy primer for rail transit coating prepared by the present invention needs to be achieved within a specific composition and ratio range.

[0125] It should be noted that, in order to make the description concise, not all possible combinations of the various technical features in the above embodiments are described. The above embodiments only express several implementation methods of the present invention, and the description is relatively specific and detailed, but it cannot be understood as limiting the scope of the invention patent. It should be pointed out that for ordinary technicians in the field, without departing from the concept of the present invention, the technicians in the field can combine and combine the different embodiments and features of the different embodiments described in this specification, which all belong to the protection scope of the present invention.

Claims

1. A water-based two-component epoxy primer for rail transit coating, characterized in that: The epoxy primer is composed of component A and component B. Component A includes 25-50 parts of waterborne epoxy resin dispersion, 1-5 parts of cosolvent, 0.3-2.0 parts of dispersant, 0.1-1.0 parts of wetting agent, 10-22 parts of superfine barium sulfate, 10-20 parts of titanium dioxide, 5-20 parts of superfine talc, 2-8 parts of rust-proof pigment, 0.2-1.0 parts of defoamer, 0.2-1.0 parts of rheological agent, 0.1-5.0 parts of carbon black, 0.1-2.0 parts of anti-sagging agent and 10-25 parts of deionized water by weight. The component B comprises 20-35 parts of ethylene glycol monobutyl ether, 40-60 parts of modified amine curing agent, 2-5 parts of anti-flash rust agent, and 20-35 parts of deionized water; The waterborne epoxy resin dispersion comprises BECKOPOX TM Two or more of EP 384w / 53WAMP, LianGu Banco 2095, Tongde 3EE102W; The modified amine curing agent comprises a modified amine curing agent I and a modified amine curing agent II, wherein the modified amine curing agent I is selected from Huntsman Aradur® 3986 and / or Huntsman Aradur 38-1, and the modified amine curing agent II is selected from Qirun EH 3504; The allnex BECKOPOX TM The mass ratio of EP 384w / 53WAMP, Liangu Banco 2095, and Tongde 3EE102W is (2~5):1:(0~0.5); The rheological agent is a mixture of Evonik AEROSIL 200 and / or Evonik AEROSIL 380 and Hemmings LT; The mass ratio of Evonik AEROSIL 200 and / or Evonik AEROSIL 380 to Hemmings LT in the rheological agent is 1:4-7; the mass ratio of Borchi® Gel 0620, Digo 3060, and Hemmings 105A in the anti-sagging agent is 3-5:1-2:1-2.

2. The water-based two-component epoxy primer for rail transit coating according to claim 1, characterized in that: The mass ratio of the modified amine curing agent I to the modified amine curing agent II is 1:2-5.

3. The water-based two-component epoxy primer for rail transit coating according to claim 1, characterized in that: The dispersant in component A is Digo 755W and / or Hemmings FX600; the wetting agent is Digo 4100 and / or Air Chemical SURFYNOL 104BC; the anti-rust pigment is selected from any one or more of REALCARE WS10ES of Huagao Ke, APW-Ⅱ of Guangxi Xinjing, zinc phosphate, Aolin 908-I, 908-II ultrafine phosphorus iron anti-rust powder, Aolin PZS-II ultrafine phosphorus iron zinc silicon powder; the defoaming agent is Digo 902w and / or BASF Foamstar ST2437; the ultrafine barium sulfate is 1250 mesh, and the ultrafine talc is 1250 mesh; the cosolvent is selected from any one or more of ethylene glycol monobutyl ether, propylene glycol methyl ether, diethylene glycol butyl ether, and dipropylene glycol butyl ether; The flash rust inhibitor in the component B is selected from one or more of Raybo 60, FA179, and ASCOTRAN-H10.

4. The water-based two-component epoxy primer for rail transit coating according to claim 3, characterized in that: The mass ratio of Digo 4100 to Air Chemical SURFYNOL 104BC in the wetting agent is 1:1-5.

5. The water-based two-component epoxy primer for rail transit coating according to claim 3, characterized in that: The anti-rust pigment is a mixture of Huagaoke REALCARE WS10ES, Guangxi Xinjing APW-Ⅱ, and PZS-II ultrafine phosphorus iron zinc silicon powder, and the mass ratio of Huagaoke REALCARE WS10ES, Guangxi Xinjing APW-Ⅱ, and PZS-II ultrafine phosphorus iron zinc silicon powder is 3:1~3:

1.

6. The water-based two-component epoxy primer for rail transit coating according to claim 1, characterized in that: The mass ratio of component A to component B is 5-7:

1.

7. A method for preparing the water-based two-component epoxy primer for rail transit coating according to any one of claims 1 to 6, characterized in that: The following steps are involved: Preparation of component A: S1, mixing the dispersant, wetting agent, defoamer, rheological agent and deionized water in the formula, stirring at 200-300 r / min for 5-30 min, adding ultrafine barium sulfate, titanium dioxide, ultrafine talcum powder, carbon black and anti-rust pigment, stirring at 500-800 r / min for 30-60 min, and then sand grinding to obtain a water-based primer slurry; S2. Add the water-based primer slurry and the cosolvent prepared in step S1 to the water-based epoxy resin dispersion at a stirring speed of 200-300 r / min, and continue stirring for 20-30 min; S3, adding an anti-sagging agent to step S2, stirring at 300-600 r / min for 20-40 min to obtain component A; Preparation of component B: Component B is prepared by mixing ethylene glycol monobutyl ether, modified amine curing agent, anti-flash rust agent and deionized water.

8. The method according to claim 7, characterized in that The fineness of the sand grinding is less than 20 μm.

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