Water-based epoxy primer for train and preparation method of water-based epoxy primer

Abstract

The invention relates to the technical field of epoxy primer, and discloses a water-based epoxy primer for trains and a preparation method thereof.The preparation method comprises the steps that diethanol amine, dodecafluoro-1, 9-decadiene, maleic anhydride and the like serve as raw materials, an intermediate 2 is prepared through a reaction, the intermediate 2 is grafted into epoxy resin under the initiation of an initiator, and the epoxy primer is prepared through a one-step reaction; the phosphoric acid is introduced into the epoxy resin through a ring-opening reaction with epoxy groups in the epoxy resin, and the water-based epoxy primer for the train is further prepared. The surface energy of the epoxy primer is reduced by using fluorine in the epoxy primer, so that the waterproof effect of the epoxy resin is improved, and the adhesive force and the anti-corrosion effect of the epoxy resin are enhanced by forming a complex with a train metal substrate by using phosphoric acid and a carboxyl structure in the epoxy primer. The water-based epoxy primer prepared by the preparation method disclosed by the invention has a relatively good waterproof effect and a relatively good anti-corrosion effect.

Description

Technical Field

[0001] The invention relates to the technical field of epoxy primers, in particular to a water-based epoxy primer for trains and a preparation method thereof. Background Art

[0002] With the development of science and technology and the enhancement of world trade exchanges, the rail transit industry, as a national pillar industry, has a large amount of use. During the operation of trains, they will experience the test of various climates such as high cold, high heat, wind and sand, and will suffer a lot of losses due to corrosion, resulting in serious energy waste. Therefore, the anti-corrosion performance of the protective coating of train vehicles is required to be high. Therefore, how to improve the anti-corrosion performance of protective primers for trains is one of the hot topics of research.

[0003] Waterborne epoxy coatings are generally made from epoxy resins, curing agents, etc. They have excellent adhesion and corrosion resistance and are widely used in rail transit, engineering machinery, marine corrosion protection and other fields. Therefore, waterborne epoxy primers are often used as protective coatings in the use of train primers.

[0004] For example, the patent with application publication number CN 115975481 A discloses an epoxy resin anti-corrosion coating and a preparation method thereof. The invention uses epoxy resin, foamed graphene, polyamide curing agent, etc. as raw materials. The prepared epoxy resin coating has good anti-corrosion effect, but does not improve the waterproof effect of the epoxy resin coating. Summary of the invention

[0005] The purpose of the present invention is to provide a water-based epoxy primer for trains and a preparation method thereof, which is modified by a water-based epoxy resin emulsion to enhance the waterproof and anti-corrosion effects of the water-based epoxy primer to solve the above-mentioned existing problems.

[0006] To achieve the above object, the present invention provides a water-based epoxy primer for trains, the water-based epoxy primer for trains comprising component A and component B, the component A and component B are packaged separately, and when used, component A and component B are mixed evenly at a mass ratio of 4:1;

[0007] Preferably, the component A is prepared from the following raw materials in parts by weight: 100 parts of fluorine-modified waterborne epoxy resin emulsion, 1-2.5 parts of dispersant, 0.5-1 parts of defoamer, 5-15 parts of talc, 0.2-0.5 parts of white carbon black, 0.4-1 parts of wetting agent, 0.2-0.5 parts of rheological additive, 1-2 parts of propylene glycol methyl ether, 30-50 parts of deionized water, 1-2 parts of thickener, and 0.5-1.5 parts of anti-flash rust agent.

[0008] Preferably, the method for preparing component A comprises the following steps:

[0009] 1-2.5 parts by weight of a dispersant, 0.5-1 parts by weight of a defoamer, 5-15 parts by weight of talc, 0.2-0.5 parts by weight of white carbon black, and 30-50 parts by weight of deionized water are added to a sand mill, ground to a fineness of ≦30 μm, filtered, and then 100 parts by weight of a fluorine-modified waterborne epoxy resin emulsion, 0.4-1 parts by weight of a wetting agent, 1-2 parts by weight of propylene glycol methyl ether, 0.2-0.5 parts by weight of a rheological additive, 1-2 parts by weight of a thickener, and 0.5-1.5 parts by weight of an anti-flash rust agent are added thereto, and the mixture is stirred and dispersed for 30 minutes to obtain component A.

[0010] Preferably, the preparation method of the fluorine-modified waterborne epoxy resin emulsion is:

[0011] (1) Add diethanolamine to toluene solvent, stir and disperse, add dodecafluoro-1,9-decadiene at 0-5°C, stir and mix evenly, heat to react, and after the reaction is completed, distill under reduced pressure, wash with deionized water, and dry to obtain intermediate 1. The reaction synthesis route is as follows:

[0012]

[0013] (2) Add maleic anhydride and intermediate 1 to toluene solvent, stir and disperse, heat to 100-120° C., stir and react for 2-5 hours. After the reaction is completed, distill under reduced pressure, wash with deionized water, and dry to obtain intermediate 2. The reaction synthesis route is:

[0014]

[0015] (3) Add the epoxy resin to the n-butanol solvent, stir and disperse, heat to 75-85°C, add phosphoric acid, keep warm and react for 40-80 minutes, then add the intermediate 2 and benzoyl peroxide, react at 100-120°C for 5-8 hours, after the reaction, cool to 60-70°C, add N,N-dimethylethanolamine, adjust the pH to 7-8, finally add deionized water, stir and mix evenly, and obtain a fluorine-modified waterborne epoxy resin emulsion.

[0016] Preferably, in (1), the mass ratio of diethanolamine to dodecafluoro-1,9-decadiene is 60-80:100.

[0017] Preferably, in said (1), the temperature of the temperature-raising reaction is 80-90° C. and the time is 20-50 min.

[0018] Preferably, in (2), the mass ratio of maleic anhydride to intermediate 1 is 70-85:100.

[0019] Preferably, in (3), the mass ratio of epoxy resin, phosphoric acid, intermediate 2, benzoyl peroxide and deionized water is 100:3-5:10-30:5-10:150-200.

[0020] Preferably, the component B is a curing agent.

[0021] Reaction mechanism: The present invention uses diethanolamine, dodecafluoro-1,9-decadiene, maleic anhydride and the like as raw materials, and obtains intermediate 2 through reaction preparation; phosphoric acid is used to attack the epoxy ring in the epoxy resin, that is, phosphoric acid and epoxy undergo a ring-opening reaction, and phosphoric acid is introduced into the epoxy resin; benzoyl peroxide initiator is used to initiate graft polymerization of the secondary hydroxyl group in the repeating chain segment of the epoxy resin and the active hydrogen on the methylene with intermediate 2 to obtain fluorine-modified waterborne epoxy resin emulsion. Fluorine-modified waterborne epoxy resin emulsion, wetting agent, rheological additive and the like are added to the mixture of the ground dispersant, talcum powder, white carbon black and the like, and mixed evenly to obtain component A, to which a curing agent is added, and finally a waterborne epoxy primer for trains is obtained.

[0022] Beneficial effects of the present invention: The fluorine element used in the present invention has a relatively low surface energy, and its introduction into the epoxy primer can improve the waterproof and antifouling effect of the epoxy primer. The epoxy primer prepared by the present invention contains phosphoric acid and carboxyl groups, both of which have a strong chelating effect with the metal base surface on the train, and can form a complex with multivalent metals to form a complex, and firmly connect the polymer to the metal substrate of the train in the form of a covalent bond, thereby enhancing the adhesion of the polymer coating on the metal substrate, and forming a dense film on the metal surface of the train to achieve a good anti-corrosion effect. The water-based epoxy primer prepared by the present invention has good waterproof and anti-corrosion effects. DETAILED DESCRIPTION

[0023] The following non-limiting embodiments may enable a person skilled in the art to more fully understand the present invention, but are not intended to limit the present invention in any way.

[0024] The epoxy resin is epoxy resin E-12;

[0025] The dispersant is dispersant BYK-190;

[0026] The defoamer is defoamer BYK-093;

[0027] The wetting agent is Tego4100 substrate wetting agent;

[0028] The rheological additive is 299 rheological additive;

[0029] The thickener was Thickener GmbH Borchi 0620;

[0030] The anti-flash rust agent is anti-flash rust agent NALZIN FA179;

[0031] The curing agent is water-based epoxy curing agent HGH300.

[0032] Example 1

[0033] (1) Add 60 parts by weight of diethanolamine to a toluene solvent, stir and disperse, add 100 parts by weight of dodecafluoro-1,9-decadiene at 0° C., stir and mix evenly, heat to 85° C., react for 30 min, and after the reaction is completed, distill under reduced pressure, wash with deionized water, and dry to obtain an intermediate 1.

[0034] (2) According to weight portions, 75 parts by weight of maleic anhydride and 100 parts by weight of intermediate 1 were added to toluene solvent, stirred and dispersed, heated to 110° C., stirred and reacted for 4 hours. After the reaction was completed, the mixture was distilled under reduced pressure, washed with deionized water, and dried to obtain intermediate 2.

[0035] (3) According to weight, 100 parts by weight of epoxy resin were added to n-butanol solvent, stirred and dispersed, heated to 75°C, 3 parts by weight of phosphoric acid were added thereto, and the reaction was kept warm for 60 minutes, and then 10 parts by weight of intermediate 2 and 8 parts by weight of benzoyl peroxide were added thereto, and the reaction was carried out at 110°C for 8 hours. After the reaction was completed, the temperature was lowered to 70°C, N,N-dimethylethanolamine was added thereto, and the pH was adjusted to 7. Finally, 200 parts by weight of deionized water were added thereto, and the mixture was stirred and mixed uniformly to obtain a fluorine-modified waterborne epoxy resin emulsion.

[0036] (4) According to weight parts, 1.5 parts by weight of a dispersant, 0.8 parts by weight of a defoamer, 10 parts by weight of talc, 0.4 parts by weight of white carbon black, and 40 parts by weight of deionized water are added to a sand mill, ground to a fineness of ≦30 μm, filtered, and then 100 parts by weight of a fluorine-modified waterborne epoxy resin emulsion, 0.5 parts by weight of a wetting agent, 1.5 parts by weight of propylene glycol methyl ether, 0.4 parts by weight of a rheological additive, 2 parts by weight of a thickener, and 1 part by weight of an anti-flash rust agent are added thereto, and stirred and dispersed for 30 minutes to obtain component A.

[0037] (5) When in use, mix components A and B in a ratio of 4:1 to obtain a water-based epoxy primer for trains.

[0038] Example 2

[0039] (1) According to weight, 70 parts by weight of diethanolamine were added to a toluene solvent, and the mixture was stirred and dispersed. At 0° C., 100 parts by weight of dodecafluoro-1,9-decadiene were added thereto, and the mixture was stirred and mixed evenly. The mixture was heated to 85° C. and reacted for 40 minutes. After the reaction was completed, the mixture was distilled under reduced pressure, washed with deionized water, and dried to obtain an intermediate 1.

[0040] (2) According to weight, 80 parts by weight of maleic anhydride and 100 parts by weight of intermediate 1 were added to toluene solvent, stirred and dispersed, heated to 120° C., stirred and reacted for 4 hours. After the reaction was completed, it was distilled under reduced pressure, washed with deionized water, and dried to obtain intermediate 2.

[0041] (3) According to weight, 100 parts by weight of epoxy resin were added to n-butanol solvent, stirred and dispersed, heated to 85°C, 3.5 parts by weight of phosphoric acid were added thereto, and the reaction was kept warm for 80 minutes. Then, 15 parts by weight of intermediate 2 and 5 parts by weight of benzoyl peroxide were added thereto, and the reaction was carried out at 120°C for 5 hours. After the reaction was completed, the temperature was lowered to 60°C, N,N-dimethylethanolamine was added thereto, and the pH was adjusted to 8. Finally, 180 parts by weight of deionized water were added thereto, and the mixture was stirred and mixed evenly to obtain a fluorine-modified waterborne epoxy resin emulsion.

[0042] (4) Add 1.5 parts by weight of a dispersant, 0.8 parts by weight of a defoamer, 12 parts by weight of talc, 0.4 parts by weight of white carbon black, and 50 parts by weight of deionized water into a sand mill, grind to a fineness of ≦30 μm, filter, and then add 100 parts by weight of a fluorine-modified waterborne epoxy resin emulsion, 0.4 parts by weight of a wetting agent, 2 parts by weight of propylene glycol methyl ether, 0.4 parts by weight of a rheological additive, 1 part by weight of a thickener, and 1.5 parts by weight of an anti-flash rust agent, stir and disperse for 30 minutes to obtain component A.

[0043] (5) When in use, mix components A and B in a ratio of 4:1 to obtain a water-based epoxy primer for trains.

[0044] Example 3

[0045] (1) 80 parts by weight of diethanolamine were added to a toluene solvent and stirred for dispersion. 100 parts by weight of dodecafluoro-1,9-decadiene were added thereto at 5° C. and stirred for uniform mixing. The mixture was heated to 90° C. and reacted for 20 min. After the reaction was completed, the mixture was distilled under reduced pressure, washed with deionized water, and dried to obtain an intermediate 1.

[0046] (2) According to weight, 75 parts by weight of maleic anhydride and 100 parts by weight of intermediate 1 were added to toluene solvent, stirred and dispersed, heated to 110° C., stirred and reacted for 2 h. After the reaction was completed, vacuum distillation was performed, the mixture was washed with deionized water, and dried to obtain intermediate 2.

[0047] (3) According to weight, 100 parts by weight of epoxy resin were added to n-butanol solvent, stirred and dispersed, heated to 80°C, 4 parts by weight of phosphoric acid were added thereto, and the reaction was kept warm for 40 minutes. Then, 20 parts by weight of intermediate 2 and 10 parts by weight of benzoyl peroxide were added thereto, and the reaction was carried out at 100°C for 6 hours. After the reaction was completed, the temperature was lowered to 65°C, N,N-dimethylethanolamine was added thereto, and the pH was adjusted to 7. Finally, 150 parts by weight of deionized water were added thereto, and the mixture was stirred and mixed uniformly to obtain a fluorine-modified waterborne epoxy resin emulsion.

[0048] (4) According to weight parts, 1 weight part of dispersant, 1 weight part of defoamer, 15 weight parts of talc, 0.2 weight part of white carbon black, and 40 weight parts of deionized water are added to a sand mill, ground to a fineness of ≦30 μm, filtered, and then 100 weight parts of fluorine-modified waterborne epoxy resin emulsion, 0.5 weight part of wetting agent, 2 weight parts of propylene glycol methyl ether, 0.3 weight part of rheological additive, 2 weight parts of thickener, and 0.5 weight part of anti-flash rust agent are added thereto, and stirred and dispersed for 30 minutes to obtain component A.

[0049] (5) When in use, mix components A and B in a ratio of 4:1 to obtain a water-based epoxy primer for trains.

[0050] Example 4

[0051] (1) According to weight, 70 parts by weight of diethanolamine were added to a toluene solvent, and the mixture was stirred and dispersed. At 0° C., 100 parts by weight of dodecafluoro-1,9-decadiene were added thereto, and the mixture was stirred and mixed uniformly. The mixture was heated to 80° C. and reacted for 50 min. After the reaction was completed, the mixture was distilled under reduced pressure, washed with deionized water, and dried to obtain an intermediate 1.

[0052] (2) According to weight, 85 parts by weight of maleic anhydride and 100 parts by weight of intermediate 1 were added to toluene solvent, stirred and dispersed, heated to 100° C., stirred and reacted for 5 hours. After the reaction was completed, it was distilled under reduced pressure, washed with deionized water, and dried to obtain intermediate 2.

[0053] (3) According to weight, 100 parts by weight of epoxy resin were added to n-butanol solvent, stirred and dispersed, heated to 80°C, 4.5 parts by weight of phosphoric acid were added thereto, and the reaction was kept warm for 50 minutes. Then, 25 parts by weight of intermediate 2 and 8 parts by weight of benzoyl peroxide were added thereto, and the reaction was carried out at 110°C for 6 hours. After the reaction was completed, the temperature was lowered to 65°C, N,N-dimethylethanolamine was added thereto, and the pH was adjusted to 8. Finally, 190 parts by weight of deionized water were added thereto, and the mixture was stirred and mixed evenly to obtain a fluorine-modified waterborne epoxy resin emulsion.

[0054] (4) Add 2.5 parts by weight of a dispersant, 0.5 parts by weight of a defoamer, 10 parts by weight of talc, 0.5 parts by weight of white carbon black, and 30 parts by weight of deionized water into a sand mill, grind to a fineness of ≦30 μm, filter, and then add 100 parts by weight of a fluorine-modified waterborne epoxy resin emulsion, 1 part by weight of a wetting agent, 2 parts by weight of propylene glycol methyl ether, 0.2 parts by weight of a rheological additive, 1 part by weight of a thickener, and 1 part by weight of an anti-flash rust agent, stir and disperse for 30 minutes to obtain component A.

[0055] (5) When in use, mix components A and B in a ratio of 4:1 to obtain a water-based epoxy primer for trains.

[0056] Example 5

[0057] (1) According to weight, 70 parts by weight of diethanolamine were added to a toluene solvent, and the mixture was stirred and dispersed. At 5° C., 100 parts by weight of dodecafluoro-1,9-decadiene were added thereto, and the mixture was stirred and mixed uniformly. The mixture was heated to 85° C. and reacted for 50 min. After the reaction was completed, the mixture was distilled under reduced pressure, washed with deionized water, and dried to obtain an intermediate 1.

[0058] (2) According to weight, 70 parts by weight of maleic anhydride and 100 parts by weight of intermediate 1 were added to toluene solvent, stirred and dispersed, heated to 120° C., stirred and reacted for 4 hours. After the reaction was completed, it was distilled under reduced pressure, washed with deionized water, and dried to obtain intermediate 2.

[0059] (3) According to weight, 100 parts by weight of epoxy resin were added to n-butanol solvent, stirred and dispersed, heated to 80°C, 5 parts by weight of phosphoric acid were added thereto, and the reaction was kept warm for 50 minutes. Then, 30 parts by weight of intermediate 2 and 9 parts by weight of benzoyl peroxide were added thereto, and the reaction was carried out at 110°C for 7 hours. After the reaction was completed, the temperature was lowered to 65°C, N,N-dimethylethanolamine was added thereto, and the pH was adjusted to 8. Finally, 200 parts by weight of deionized water were added thereto, and the mixture was stirred and mixed to obtain a fluorine-modified waterborne epoxy resin emulsion.

[0060] (4) Add 2 parts by weight of a dispersant, 0.6 parts by weight of a defoamer, 5 parts by weight of talc, 0.4 parts by weight of white carbon black, and 50 parts by weight of deionized water into a sand mill, grind to a fineness of ≦30 μm, filter, and then add 100 parts by weight of a fluorine-modified waterborne epoxy resin emulsion, 0.4 parts by weight of a wetting agent, 1 part by weight of propylene glycol methyl ether, 0.5 parts by weight of a rheological additive, 1.5 parts by weight of a thickener, and 1 part by weight of an anti-flash rust agent, stir and disperse for 30 minutes to obtain component A.

[0061] (5) When in use, mix components A and B in a ratio of 4:1 to obtain a water-based epoxy primer for trains.

[0062] Comparative Example 1

[0063] The difference between this comparative example and Example 1 is that in step (3), no phosphoric acid is contained.

[0064] Comparative Example 2

[0065] The difference between this comparative example and Example 1 is that in step (3), intermediate 2 is not contained.

[0066] The water-based epoxy primer for the train was evenly coated on the tinplate, placed at room temperature for 2 hours, then placed at 160°C for curing for 4 hours, taken out, and placed at room temperature for 24 hours to obtain a paint film.

[0067] Adhesion performance test: Refer to GB / T9286-2021 to test the adhesion of water-based epoxy primer. Make 6 cross-cut lines at an interval of 1mm on the test board, stick glass glue on it, and then peel it off. The area of ​​the paint film that falls off from the substrate in the crossed area is evaluated, divided into 0-5 levels, with 0 being the best and 5 being the worst.

[0068] Corrosion performance test: The selected double-unit electrochemical workstation adopts a three-motor system, with 3.5% NaCl solution as the test solution, platinum sheet as the auxiliary motor, saturated calomel as the reference motor, and tinplate coated with primer as the experimental test electrode.

[0069] Waterproof performance test: Use a contact angle meter to measure the contact angle between the coating specimen and water. Dry at 60°C for 4 hours before measurement. Take 5 points (with a spacing of not less than 1 cm) for each specimen and take the average value.

[0070] Table 1 Performance test

[0071]

[0072]

[0073] The larger the contact angle, the better the waterproof effect, the smaller the corrosion rate, and the better the anti-corrosion effect. As can be seen from the table, the waterborne epoxy primer prepared by the present invention has good adhesion, anti-corrosion effect and waterproof effect, the minimum corrosion rate can reach 0.00248mm / a, and the maximum contact angle can reach 108.6°.

[0074] For any technician familiar with the art, without departing from the scope of the technical solution of the present invention, the technical content disclosed above can be used to make many possible changes and modifications to the technical solution of the present invention, or modified into equivalent embodiments with equivalent changes. Therefore, any simple modification, equivalent change and modification made to the above embodiments according to the technical essence of the present invention without departing from the content of the technical solution of the present invention should still fall within the scope of protection of the technical solution of the present invention.

Claims

1. A water-based epoxy primer for trains, characterized in that: The water-based epoxy primer for trains comprises component A and component B. When used, component A and component B are evenly mixed in a mass ratio of 4:1; The component A is prepared from the following raw materials in parts by weight: 100 parts of fluorine-modified waterborne epoxy resin emulsion, 1-2.5 parts of dispersant, 0.5-1 parts of defoamer, 5-15 parts of talc, 0.2-0.5 parts of white carbon black, 0.4-1 parts of wetting agent, 0.2-0.5 parts of rheological additive, 1-2 parts of propylene glycol methyl ether, 30-50 parts of deionized water, 1-2 parts of thickener, and 0.5-1.5 parts of anti-flash rust agent; The preparation method of the component A comprises the following steps: 1-2.5 parts by weight of a dispersant, 0.5-1 parts by weight of a defoamer, 5-15 parts by weight of talc, 0.2-0.5 parts by weight of white carbon black, and 30-50 parts by weight of deionized water are added to a sand mill, ground to a fineness of ≦30 μm, filtered, and then 100 parts by weight of a fluorine-modified waterborne epoxy resin emulsion, 0.4-1 parts by weight of a wetting agent, 1-2 parts by weight of propylene glycol methyl ether, 0.2-0.5 parts by weight of a rheological additive, 1-2 parts by weight of a thickener, and 0.5-1.5 parts by weight of an anti-flash rust agent are added thereto, and stirred and dispersed for 30 minutes to obtain component A; The component B is a curing agent.

2. The water-based epoxy primer for trains according to claim 1, characterized in that: The preparation method of the fluorine-containing modified waterborne epoxy resin emulsion is: (1) adding diethanolamine to a toluene solvent, stirring and dispersing, adding dodecafluoro-1,9-decadiene thereto at 0-5° C., stirring and mixing evenly, heating to react, and after the reaction is completed, distilling under reduced pressure, washing with deionized water, and drying to obtain an intermediate 1; (2) adding maleic anhydride and intermediate 1 to toluene solvent, stirring and dispersing, heating to 100-120° C., stirring and reacting for 2-5 hours, and after the reaction is completed, distilling under reduced pressure, washing with deionized water, and drying to obtain intermediate 2; (3) Add the epoxy resin to the n-butanol solvent, stir and disperse, heat to 75-85°C, add phosphoric acid, keep warm and react for 40-80 minutes, then add the intermediate 2 and benzoyl peroxide, react at 100-120°C for 5-8 hours, after the reaction, cool to 60-70°C, add N,N-dimethylethanolamine, adjust the pH to 7-8, finally add deionized water, stir and mix evenly, and obtain a fluorine-modified waterborne epoxy resin emulsion.

3. The water-based epoxy primer for trains according to claim 2, characterized in that: In the above (1), the mass ratio of diethanolamine to dodecafluoro-1,9-decadiene is 60-80:

100.

4. The water-based epoxy primer for trains according to claim 2, characterized in that: In the above-mentioned step (1), the temperature of the temperature-raising reaction is 80-90° C. and the time is 20-50 min.

5. The water-based epoxy primer for trains according to claim 2, characterized in that: In the above (2), the mass ratio of maleic anhydride to intermediate 1 is 70-85:

100.

6. The water-based epoxy primer for trains according to claim 2, characterized in that: In the above (3), the mass ratio of epoxy resin, phosphoric acid, intermediate 2, benzoyl peroxide and deionized water is 100:3-5:10-30:5-10:150-200.

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