Modified epoxy water-based putty suitable for rail transit vehicles and preparation method of modified epoxy water-based putty

Abstract

The invention provides modified epoxy water-based putty suitable for rail transit vehicles and a preparation method of the modified epoxy water-based putty, and belongs to the technical field of putty. The hyperbranched polyester modified epoxy resin is added into the main agent component; acrylonitrile modified aliphatic amine is selected in the curing agent component, and other specific components are matched with one another; based on the matched preparation method, the prepared putty product has the characteristics of strong adhesive force, high strength and high toughness; meanwhile, the coating is long in construction service time, high in curing speed, good in grinding property, suitable for large-area coating and scraping and the like, and particularly capable of meeting the coating use of rail transit vehicles.

Description

Technical Field

[0001] The invention belongs to the technical field of putty and relates to an epoxy water-based putty and a preparation method thereof, and in particular to a modified epoxy water-based putty suitable for rail transit vehicles and a preparation method thereof. Background Art

[0002] Unsaturated polyester putty (atom putty) products used in rail transit vehicle putty are generally based on unsaturated polyester resins, which contain 30-40% of traditional monomers such as styrene, methyl styrene, other vinyl derivatives of benzene, and acrylates. During application (for inlay coating), these unsaturated polyester putties often contain residual monomer compounds (primarily styrene) that fail to react and volatilize into the air. This can cause irritation to the nose, eyes, throat, and skin, particularly at construction sites during hot weather, seriously impacting the health of workers. On June 10, 2011, the U.S. Department of Health and Human Services (HHS) and the National Institute of Environmental Health Sciences (NIEHS) published their 12th "Carcinogen Report," announcing that styrene would become a newly designated carcinogen in the United States. In 2016, it was officially listed as a carcinogen by the California Office of Environmental Health Hazard Assessment (OEHHA) on the California Prohibition 65 List. Furthermore, according to the "Standard for Hygienic Design of Industrial Enterprises (TJ36-79)," the maximum permissible concentration of styrene in production air is 40 mg / m³. 3 The maximum allowable concentration of styrene in the atmosphere of residential areas is 0.01 mg / m 3 Therefore, the market is eager for the emergence of a high-performance, environmentally friendly putty product that does not contain traditional reactive diluents such as styrene.

[0003] Epoxy resins are widely used in industrial corrosion protection, bonding, and flooring due to their excellent properties, including high adhesion, high mechanical strength, strong chemical resistance, and high insulation. However, because epoxy resins are generally insoluble in water, traditional epoxy resins typically require the addition of large amounts of solvents to reduce viscosity for ease of application. This results in the production and use of volatile organic compounds, which are released into the environment, causing pollution and posing a threat to human health. Solvent-based epoxy putties made from epoxy resins typically contain highly volatile and destructive organic solvents. Furthermore, the volatile gases often contain many environmentally harmful substances, which can damage exterior wall insulation and shorten the building's service life.

[0004] In recent years, with rising environmental awareness and increasingly stringent national environmental regulations, the trend toward water-based putties has become inevitable. Consequently, the development of environmentally friendly water-based putties has become a trend, leading to the increasing prevalence of water-based epoxy emulsions. However, these putties have come with a host of challenges, including insufficient strength, toughness, and stability. Currently, water-based putties are scarce on the market. While some putties meet construction standards, they suffer from poor performance and stability.

[0005] Although the prior art CN105238123A uses polyurethane-modified epoxy resin to make the putty meet the requirements for flexibility, its solvents are xylene and n-butanol, which have very high requirements for the base material and there is a risk of solvent biting and damaging the protective layer; CN101412862A discloses a water-based epoxy putty, however, the putty layer has insufficient toughness and is prone to cracking; CN113881315A utilizes the advantages of hyperbranched resin to achieve significantly improved flexibility and adhesion of hyperbranched modified epoxy resin coatings, but the hyperbranched polyester resin modified epoxy is used in powder coatings, and the curing temperature exceeds 150°C, which is very different from the application scenarios of putty products cured at room temperature or low temperature; CN117924990A improves the crosslinking stability of epoxy resin based on multi-crosslinking and polymer brush-type nanowire structure, reduces shrinkage, and introduces hydrophobic polycaprolactone to improve the water resistance of the cured product, but does not improve the flexibility of the cured product, resulting in low bonding strength and no improvement in adhesion of the putty, and does not meet actual needs well.

[0006] To this end, a water-based putty product is needed that has high toughness, high bonding strength, good stability, can be cured at room temperature or low temperature, does not produce harmful substances such as styrene, and is suitable for rail transit vehicles. Summary of the Invention

[0007] To overcome the shortcomings of the existing technology, a modified epoxy water-based putty suitable for rail transit vehicles and a preparation method thereof are provided. In this technical solution, by adding a hyperbranched polyester-modified epoxy resin to the main agent component A; selecting an acrylonitrile-modified fatty amine as the curing agent component B; and the mutual coordination of other specific components; and based on a matching preparation method, the prepared putty product is guaranteed to have strong adhesion, high strength, and high toughness. At the same time, it has a long construction and use life, a fast curing speed, good polishability, and is suitable for large-area coating, etc., which is particularly suitable for rail transit vehicle painting.

[0008] In order to achieve the above technical objectives, the following technical solutions are proposed:

[0009] The first purpose of the present technical solution is to provide: a modified epoxy water-based putty suitable for rail transit vehicles, comprising a main agent component A and a curing agent component B, wherein the weight ratio of the main agent component A to the curing agent component B is 3-5:2;

[0010] The main agent component A comprises, by weight percentage, 15-20% of base epoxy resin, 2-5% of hyperbranched polyester modified epoxy resin, 4-11% of auxiliary agent, 40-65% of filler A, 0.3-0.7% of wetting agent, 6-14% of solvent and 0.8-1.5% of anti-flash rust agent;

[0011] In terms of weight percentage, the curing agent component B comprises: 20-30% of modified fatty amine, 2.5-6% of auxiliary agent, 40-60% of filler B, 13-25% of solvent, 0.5-1% of anti-flash rust agent and 0.5-1% of wetting agent;

[0012] Furthermore, the base epoxy resin is commercially available E-51 epoxy resin, CYD-128 epoxy resin (Yueyang Baling Petrochemical), or EPIKOTE828 epoxy resin (Hexion, USA). The base epoxy resin is the main film-forming substance, and the technical requirements are to provide adhesion and hardness, which is coordinated with the subsequent amine-modified curing agent in the curing agent component B;

[0013] Furthermore, the hyperbranched polyester modified epoxy resin is a yellow transparent liquid with a molecular weight of 3200-3600 g / mol, an epoxy value of 0.20-0.25 mol / 100 g, a solid content ≥99%, a VOC ≤1.0%, and a viscosity of 500-700 cp. The hyperbranched polyester modified epoxy resin is preferably a carboxyl-terminated hyperbranched polyester modified epoxy resin, such as: commercially available HyPerE102 (Wuhan Hyperbranched Resin Technology Co., Ltd.); or, commercially available EHC 1261 (produced by Tianjin Jinjiuqiang New Materials Co., Ltd. and supervised by Beijing Institute of Chemical Technology). Technical requirements: The hyperbranched polyester modified epoxy resin must have a compatible match with the base epoxy resin.

[0014] At the same time, the hyperbranched polyester modified epoxy resin improves flexibility and curing speed; in addition, if the hyperbranched polyester modified epoxy resin is excessive, the strength of the subsequent putty film will be reduced;

[0015] Hyperbranched polyester modified epoxy resin is C6H3(CO2CH2CH2CO2C6H3) n (CO2C2H3O) m , wherein n is 8-12 (branching degree: n=8-12 indicates a highly branched structure, imparting a low viscosity of 10-100 mPa·s and high reactivity), and m is 12-18; the structural formula involved is as follows:

[0016]

[0017] More specifically, the hyperbranched polyester modified epoxy resin is , that is, involving n=9, m=12, the structural formula is as follows:

[0018]

[0019] Furthermore, the wetting agent is one of BYK-346, BYK-348, BYK-333 and TEGO TWIN 4100, or a mixture of any two or more thereof. TEGO TWIN 4100 is preferred. It is used to improve the wettability of fillers such as talc to facilitate subsequent coating.

[0020] Furthermore, the anti-flash rust agent is American Halox Flash-x-150 water-based anti-flash rust agent.

[0021] Furthermore, the modified fatty amine is a modified curing agent. More specifically, the modified fatty amine is an acrylonitrile-modified fatty amine curing agent (TEPA-ATN), which is a yellow, transparent liquid with a solids content of ≥99%, an amine value of 145-185 mg KOH / g, and a viscosity of 800-1600 mPa.s / 25°C. Acrylonitrile-modified fatty amine curing agents can significantly reduce the curing temperature and increase the curing speed, such as commercially available JJQ-WAE-B01 (produced by Tianjin Jinjiuqiang New Materials Co., Ltd. and supervised by Beijing Institute of Chemical Technology) or commercially available Kingcure 690 (produced by Fujian Wangpai Fine Chemical Co., Ltd.).

[0022] Preferably, the additives include dispersants, rheological additives and defoamers;

[0023] In terms of weight percentage, the main agent component A includes: 15-20% of base epoxy resin, 2-5% of hyperbranched polyester modified epoxy resin, 1-3% of dispersant, 2-5% of rheological additive, 1-3% of defoamer, 40-65% of filler A, 0.3-0.7% of wetting agent, 6-14% of solvent and 0.8-1.5% of anti-flash rust agent;

[0024] In terms of weight percentage, the curing agent component B comprises: 20-30% of a modified fatty amine, 1-2% of a dispersant, 0.5-1% of a rheological additive, 1-3% of a defoamer, 40-60% of a filler B, 13-25% of a solvent, 0.5-1% of a flash rust inhibitor, and 0.5-1% of a wetting agent;

[0025] Furthermore, the dispersant is DISPERBYK-199BF, DISPERBYK-2012 and One or a mixture of any two or more of Gen 1252;

[0026] Furthermore, the rheological additive is one of Ito T-550F, AEROSIL R972, AEROSIL R974, and AEROSIL 380, or a mixture of any two or more. The rheological additive has a thixotropic effect on anti-sagging and achieves pre-gelation. In addition, excessive use of the rheological additive will affect leveling. This is well suited for large-scale coating of putty for rail transit vehicles.

[0027] Furthermore, the defoamer is one of BYK-011, BYK-022, TEGO Foamex 3062, and NOPCO NXZ, or a mixture of any two or more thereof, to eliminate bubbles formed by stirring, thereby facilitating subsequent painting and reducing bubbles in the formed putty film.

[0028] Preferably, filler A comprises talc, silica powder and precipitated barium sulfate, and filler B comprises talc and silica powder;

[0029] In terms of weight percentage, the main agent component A comprises: 15-20% of base epoxy resin, 2-5% of hyperbranched polyester modified epoxy resin, 4-11% of auxiliary agent, 20-30% of talc powder, 20-30% of silica powder, 3-7% of precipitated barium sulfate, 0.3-0.7% of wetting agent, 6-14% of solvent and 0.8-1.5% of anti-flash rust agent;

[0030] In terms of weight percentage, the curing agent component B comprises: 20-30% of modified fatty amine, 2.5-6% of auxiliary agent, 20-30% of talc powder, 20-30% of silica powder, 13-25% of solvent, 0.5-1% of anti-flash rust agent and 0.5-1% of wetting agent;

[0031] Furthermore, the talc powder is 800-1250 mesh, the whiteness is ≥98% of the standard sample, and the particle size distribution D 50 =5μm. The technology requires talc powder to enhance wear resistance and reduce costs; in addition, excessive talc powder will lead to increased viscosity;

[0032] Furthermore, the silicon powder is 2500 mesh, the silicon dioxide content is ≥90%; the whiteness is 70-94% of the standard sample; the particle size distribution D 50 =5μm. Technical requirements: Improve hardness and leveling;

[0033] Furthermore, the precipitated barium sulfate has a mesh size of 1200 and a barium sulfate content of ≥97%; the whiteness is ≥92% compared with the standard sample, and the water-soluble matter content is ≤0.3%.

[0034] Preferably, the solvent includes an aqueous cosolvent and purified water;

[0035] In terms of weight percentage, the main agent component A includes: 15-20% of base epoxy resin, 2-5% of hyperbranched polyester modified epoxy resin, 4-11% of auxiliary agent, 40-65% of filler A, 0.3-0.7% of wetting agent, 3-5% of aqueous cosolvent, 3-9% of purified water and 0.8-1.5% of anti-flash rust agent;

[0036] In terms of weight percentage, the curing agent component B includes: 20-30% of modified fatty amine, 2.5-6% of auxiliary agent, 40-60% of filler B, 3-5% of aqueous cosolvent, 10-20% of purified water, 0.5-1% of anti-flash rust agent and 0.5-1% of wetting agent;

[0037] Furthermore, the aqueous cosolvent is one or a mixture of any two or more of dipropylene glycol butyl ether DPNB, propylene glycol methyl ether acetate PMA and diethylene glycol butyl ether DGB;

[0038] Furthermore, pure water is used as a dispersion medium, and the conductivity is controlled to be less than 50 μS / cm.

[0039] Among them, the product indicators of modified epoxy water-based putty include: surface drying time ≤ 2h / 25℃, actual drying time ≤ 24h / 25℃, anti-sag thickness ≥ 5mm, pencil hardness ≥ H, adhesion (cross-hatch method) of level 0, and thixotropic index (TI) > 3.5;

[0040] Sandability: easy to sand, easy to get dusty, not sticky to sandpaper;

[0041] Coating and scraping properties: easy to apply and scrape (smooth and free when applying, no sticking to the knife), no curling phenomenon;

[0042] Drying property: Mix the main agent component A and the curing agent component B evenly, dry thoroughly at room temperature (15-30℃) for 24 hours, and test according to GB1728-79 standard;

[0043] Adhesion: Strong adhesion to metal or base coating (cross-hatch test or cross-hatch test level 1 or above, tested according to GB / T31586.2 standard; pull-off adhesion ≥4.0MPa, tested according to GB / T 5210 standard);

[0044] Sandability: easy to sand, non-sticky to sandpaper, no obvious white spots, tested according to GB / T 1748 standard; during the sandability test, the coating is smoothed with sandpaper. Finally, the sandability of the putty is judged based on the amount of powder ground out per minute and the difficulty of grinding;

[0045] Flexibility (cylindrical shaft): ≤50mm, tested according to GB / T 1748 standard;

[0046] Impact resistance: ≥15cm, tested according to GB / T 1732 standard;

[0047] Water resistance test: 24h water absorption line is no more than 1mm above the horizontal surface, no swelling or softening, tested according to GB / T 1733 standard;

[0048] Composite coating performance (salt spray performance, etc.) test panels are prepared as follows: The composite coating consists of primer, putty, midcoat, and topcoat. Panels are applied sequentially, with at least 16 hours between each coat, and at least 24 hours between primer and putty. The coating is dried naturally or force-dried. Forced drying conditions include: 1.5-2 hours after spraying, followed by baking at 60±2°C for 2 hours. The primer dry film thickness is 70±5μm, the scraped putty thickness is 3-5mm, and the water-sandblasting thickness is controlled to 450±50μm. The midcoat dry film thickness is 30±5μm. The topcoat is either a medium gray solid color topcoat (50±5μm) or a basecoat (20±5μm) plus a clearcoat (50±5μm), for a total of 70±5μm. Force-dried panels are then left to dry naturally for 7 days before testing performance.

[0049] The second purpose of this technical solution is to provide: a preparation method of a modified epoxy water-based putty suitable for rail transit vehicles, comprising the following steps:

[0050] S1: Preparation of main agent component A

[0051] The base epoxy resin and the hyperbranched polyester modified epoxy resin are added to a mixing kettle I and mixed evenly; then, the auxiliary agent is added and stirred until the mixture is evenly mixed to obtain a coarse suspension without particles;

[0052] The resulting coarse suspension is conveyed to a sand mill and ground to a fineness of ≤20 μm to obtain a slurry. The slurry is then placed in a mixing kettle II, and filler A is added to the slurry at a high-speed dispersion of 1000-1200 r / min and dispersed to a fineness of ≤100 μm. The speed is then reduced to 600-800 r / min. A solvent, a flash rust inhibitor, and a wetting agent are added while stirring, and the mixture is stirred until a uniform paste is formed. The mixture is then ground in a three-roll mill I to a fineness of ≤50 μm, and the proportion of fineness <30 μm is controlled to be 5-10%, the proportion of fineness of 30-35 μm is controlled to be 60-70%, and the proportion of fineness of 35-50 μm is controlled to be 20-30%, thereby obtaining component A.

[0053] Testing, use pure water to adjust the consistency of component A to 13-15;

[0054] S2: Preparation of curing agent component B

[0055] Add the modified fatty amine into mixing kettle III, add the additives while stirring, and stir until the mixture is uniform; add filler B at a high-speed dispersion speed of 1000-1200 r / min and disperse to a fineness of ≤100 μm; reduce the speed to 600-800 r / min, add the solvent, flash rust inhibitor, and wetting agent while stirring until a uniform paste is formed, and grind it in a three-roll mill II to a fineness of ≤50 μm, and control the following: the proportion of fineness <30 μm is 5-10%, the proportion of fineness of 30-35 μm is 70-80%, and the proportion of fineness of 35-50 μm is 15-20%, thereby obtaining component B;

[0056] Testing, use purified water to adjust the consistency of component B to 12-14;

[0057] S3: Preparation of modified epoxy water-based putty

[0058] When using, mix component A and component B according to the weight ratio and stir evenly to obtain modified epoxy water-based putty.

[0059] The beneficial technical effects brought about by adopting this technical solution are:

[0060] 1. The present invention ensures that the putty has the characteristics of strong adhesion, high strength and high toughness by adding hyperbranched polyester modified epoxy resin to the main component, selecting acrylonitrile modified fatty amine in the curing agent component, and cooperating with other specific components. At the same time, it has a long construction and use time, a fast curing speed, good polishing properties, and is suitable for large-area coating, etc., which is particularly suitable for rail transit vehicle coating.

[0061] During painting, the modified epoxy water-based putty involved dries quickly and is almost unaffected by humidity. Furthermore, under the same temperature conditions, putty films of different thicknesses take essentially the same time to dry by finger pressure, allowing the next coat to be applied after the putty film has dried. Furthermore, the putty film coating does not require sanding and has excellent recoatability. It also has good compatibility with water-based and oil-based epoxy anti-corrosion primers, which dry after finger pressure without biting and exhibits excellent adhesion.

[0062] Second, in the present invention, the paste-like water-based putty prepared by using base epoxy resin, hyperbranched polyester modified epoxy resin, modified curing agent, additives, fillers, solvents, etc. not only has high toughness, high bonding strength and other properties, but also has good stability; it can be cured at room temperature or low temperature, does not produce harmful substances such as styrene, is environmentally friendly and non-toxic, has no irritating taste, does not contain formaldehyde, benzene, heavy metals and other harmful substances, and meets the requirements of contemporary technology and green environmental protection;

[0063] Third, the polyester hyperbranched modified epoxy resin in the present invention effectively reduces the activation energy of the resin curing reaction, allowing the putty to dry faster and exhibit excellent adhesion, impact resistance, and corrosion resistance. Furthermore, the putty offers advantages in performance and construction, such as ease of construction and polishing, ensuring the putty layer will not fall off or crack, effectively resolving the process issues associated with existing putties.

[0064] 4. In the present invention, hyperbranched polyester modified epoxy resin, acrylonitrile modified fatty amine and specific fillers are used to ensure a 40% reduction in VOC. At the same time, the mechanical strength is increased by 100%, that is, a balance between environmental protection and the performance of putty products is achieved; and thick coating and rapid polishing (sanding is possible in 4 hours) are supported to improve construction adaptability; in addition, this modified epoxy water-based putty product includes a main agent component A and a curing agent component B, that is, this putty product is a two-component product, and the components are separately packaged to solve the storage stability problem (shelf life ≥12 months); the thixotropic index of the putty is controlled to be greater than 3.5, thereby preventing the putty film from sagging. BRIEF DESCRIPTION OF THE DRAWINGS

[0065] Figure 1 This is a physical picture of the hyperbranched polyester modified epoxy resin of the present invention;

[0066] Figure 2 This is a physical diagram of the modified fatty amine of the present invention;

[0067] Figure 3 This is a physical picture of the functional nanomaterial in the present invention;

[0068] Figure 4 This is a physical picture of component A in the present invention in a uniform paste form;

[0069] Figure 5 This is a physical picture of component B in the present invention in a uniform paste form;

[0070] Figure 6 This is a physical picture of the modified epoxy water-based putty after coating in the present invention;

[0071] Figure 7 This is a state diagram of the modified epoxy water-based putty in the tensile test of the present invention;

[0072] Figure 8 This is a state diagram of the modified epoxy water-based putty after tensile testing in the present invention;

[0073] Figure 9 This is the test report (1) related to the modified epoxy water-based putty in the present invention;

[0074] Figure 10 This is the test report (II) related to the modified epoxy water-based putty in the present invention;

[0075] Figure 11 Schematic diagram of the cross section of the coating construction involved in the use of the modified epoxy water-based putty in the present invention;

[0076] Figure 12 The following are cross-sectional scanning electron microscope (SEM) images of putty formed by hyperbranched polyester modified epoxy resin at different addition amounts (0%, 5%, 10%, 15%, 20%) in the discussion example;

[0077] Figure 13 It is a structural block diagram of the preparation system involved in the present invention;

[0078] In the figure, 1. main agent component preparation unit, 101. mixing kettle I, 102. sand mill, 103. mixing kettle II, 104. three-roll mill I, 105. base epoxy resin feed pipe, 106. hyperbranched polyester modified epoxy resin feed pipe, 107. rheological additive feed pipe I, 108. defoaming agent feed pipe I, 109. titanium dioxide feed pipe I, 110. talc feed pipe I, 111. silica powder feed pipe I, 112. precipitated barium sulfate feed pipe I, 113. water-based color paste feed pipe, 114. auxiliary agent feed pipe I;

[0079] 2. Curing agent component preparation unit, 201. Mixing kettle III, 202. Three-roll mill II, 203. Modified fatty amine feed pipe, 204. Rheological additive feed pipe II, 205. Defoaming agent feed pipe II, 206. Talc feed pipe II, 207. Silica powder feed pipe II, 208. Additive feed pipe II;

[0080] 3. Temporary storage tank for main agent components;

[0081] 4. Temporary storage tank for curing agent components;

[0082] 6. Base material epoxy resin storage tank, 7. Hyperbranched polyester modified epoxy resin storage tank, 8. Rheological additive storage tank, 9. Defoaming agent storage tank, 10. Titanium dioxide storage tank, 11. Talc storage tank, 12. Silica powder storage tank, 13. Precipitated barium sulfate storage tank, 14. Water-based color paste storage tank, 15. Additive storage tank I, 16. Modified fatty amine storage tank, 17. Additive storage tank II, 18. PLC control system. DETAILED DESCRIPTION

[0083] The following is a clear and complete description of the technical solutions in the embodiments of the present invention. It is obvious that the embodiments described are only part of the embodiments of the present invention, not all of the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without making creative efforts are within the scope of protection of the present invention.

[0084] my country's rail transit equipment primarily consists of five categories: passenger cars, freight cars, locomotives, EMUs, and urban rail transit vehicles. During operation, rail transit vehicles face a variety of complex environmental conditions, including high and low temperatures, humidity fluctuations, vibration, and impact. Therefore, putty used in rail transit vehicles must possess a range of specific properties to ensure long-term durability and safety. Technical requirements for putty used in rail transit and other vehicles primarily include functionality, decorative properties, environmental friendliness, and workability.

[0085] Functionality requirements: Putty for rail transit vehicles must first have good functionality. The putty needs to have good adhesion to the substrate of rail transit vehicles, as well as good impact resistance and corrosion resistance to ensure the stability and durability of the coating. This helps prevent the coating from falling off and improves the integrity of the overall structure, including improving the protection function of the substrate.

[0086] Decorative requirements: Another important characteristic of putty for rail transit vehicles is decorativeness, which emphasizes appearance, primarily concerning the surface visible to the human eye. The putty must be free of crusting, unstirable lumps, easy to apply and scrape, and free of curling. All other indicators must exceed industry standards.

[0087] Environmental protection requirements: With the increasing awareness of environmental protection, the environmental protection of putty for rail transit vehicles has also become an important technical requirement. For example, the development of the modified epoxy water-based putty of the present invention is to meet environmental protection requirements and reduce the emission of volatile organic compounds (VOCs);

[0088] Construction performance requirements: Construction performance is also an important indicator for evaluating putty quality. Putty for rail transit vehicles should be easy to apply and have a moderate drying time to facilitate construction workers' operation. In addition, the putty consistency must also be appropriate to facilitate mechanized construction.

[0089] In summary, rail transit vehicles have multifaceted requirements for putty performance, requiring comprehensive consideration of functionality, decorative properties, environmental friendliness, and workability. These performance requirements ensure that rail transit vehicles can operate safely and reliably in a variety of complex environments.

[0090] The present invention is illustrated by the following examples.

[0091] And, in the following examples, the raw materials involved are:

[0092] Hyperbranched polyester modified epoxy resin is a light yellow transparent liquid (such as Figure 1), a molecular weight of 3200-3600 g / mol, an epoxy value of 0.20-0.25 mol / 100 g, a solid content ≥99%, a VOC ≤1.0%, and a viscosity of 500-700 cp. The hyperbranched polyester-modified epoxy resin is preferably a carboxyl-terminated hyperbranched polyester-modified epoxy resin, such as commercially available HyPerE102 (Wuhan Hyperbranched Resin Technology Co., Ltd.); or commercially available EHC 1261 (produced by Tianjin Jinjiuqiang New Materials Co., Ltd. and supervised by Beijing Institute of Chemical Technology).

[0093] Hyperbranched polyester modified epoxy resin , wherein n is 8-12 (branching degree: n=8-12 indicates a highly branched structure, imparting a low viscosity of 10-100 mPa·s and high reactivity), and m is 12-18; the structural formula involved is as follows:

[0094]

[0095] More specifically, the hyperbranched polyester modified epoxy resin is That is, when n=9 and m=12, the structural formula is as follows:

[0096]

[0097] The wetting agent is one of BYK-346, BYK-348, BYK-333 and TEGO TWIN 4100, or a mixture of any two or more thereof. TEGO TWIN 4100 is preferred.

[0098] The anti-flash rust agent is American Halox Flash-x-150 water-based anti-flash rust agent;

[0099] Modified fatty amine is acrylonitrile modified fatty amine curing agent (TEPA-ATN), yellow liquid (such as Figure 2 ), solids content ≥99%, amine value 145-185mg KOH / g, and viscosity 800-1600mPa.s / 25°C. Acrylonitrile-modified fatty amine curing agents can significantly reduce the curing temperature and increase the curing speed, such as commercially available JJQ-WAE-B01 (produced by Tianjin Jinjiuqiang New Materials Co., Ltd. and supervised by Beijing Institute of Chemical Technology) or commercially available Kingcure 690 (produced by Fujian Wangpai Fine Chemical Co., Ltd.).

[0100] Dispersants are DISPERBYK-199BF, DISPERBYK-2012 and One or a mixture of any two or more of Gen 1252;

[0101] The rheological additive is one of Ito T-550F, AEROSIL R972, AEROSIL R974 and AEROSIL 380, or a mixture of any two or more thereof;

[0102] The defoamer is one of BYK-011, BYK-022, TEGO Foamex 3062 and NOPCO NXZ, or a mixture of any two or more thereof;

[0103] Talc powder is 1250 mesh, whiteness is ≥98% of the standard sample, particle size distribution is D 50 =5μm;

[0104] Silica powder is 2500 mesh, with a silicon dioxide content of ≥90%; whiteness is 70-94% of the standard sample; particle size distribution D 50 = 5μm. Modified silica powder (i.e., surface-modified) is preferred, such as the 2500-mesh high-white, high-purity silica powder produced by Henan Nonferrous Jinyuan Industrial Co., Ltd., with physical and chemical indicators shown in Table 1 below. This silica powder is prepared by composite modification of silica powder with a surface modifier primarily composed of a silane coupling agent. The silica powder produced by the composite modification process has high activity, good hydrophobicity, and a small number of surface hydroxyl groups, enabling better dispersion in the resin system to enhance dispersibility.

[0105] Table 1

[0106]

[0107] The precipitated barium sulfate is 1200 mesh, the barium sulfate content is ≥97%; the whiteness is ≥92% compared with the standard sample, and the water-soluble matter content is ≤0.3%;

[0108] Example 1

[0109] This embodiment provides: a modified epoxy water-based putty suitable for rail transit vehicles, comprising a main agent component A and a curing agent component B, wherein the weight ratio of the main agent component A to the curing agent component B is 3:2;

[0110] The main agent component A comprises, by weight percentage, 20% of base epoxy resin, 5% of hyperbranched polyester modified epoxy resin, 11% of auxiliary agent, 47.8% of filler A, 0.7% of wetting agent, 14% of solvent and 1.5% of anti-flash rust agent;

[0111] Calculated by weight percentage, the curing agent component B includes: 29% of modified fatty amine, 6% of auxiliary agent, 40% of filler B, 23% of solvent, 1% of anti-flash rust agent and 1% of wetting agent.

[0112] Example 2

[0113] This embodiment provides: a modified epoxy water-based putty suitable for rail transit vehicles, comprising a main agent component A and a curing agent component B, wherein the weight ratio of the main agent component A to the curing agent component B is 5:2;

[0114] The main agent component A comprises, by weight percentage, 15% of base epoxy resin, 2% of hyperbranched polyester modified epoxy resin, 8% of auxiliary agent, 65% of filler A, 0.3% of wetting agent, 8.9% of solvent and 0.8% of flash rust inhibitor;

[0115] Calculated by weight percentage, the curing agent component B includes: 20% of modified fatty amine, 6% of auxiliary agent, 60% of filler B, 13% of solvent, 0.5% of anti-flash rust agent and 0.5% of wetting agent.

[0116] Example 3

[0117] This embodiment provides: a modified epoxy water-based putty suitable for rail transit vehicles, comprising a main agent component A and a curing agent component B, wherein the weight ratio of the main agent component A to the curing agent component B is 2:1;

[0118] The main agent component A comprises, by weight percentage, 18% of base epoxy resin, 3% of hyperbranched polyester modified epoxy resin, 10% of auxiliary agent, 57.5% of filler A, 0.5% of wetting agent, 10% of solvent and 1% of anti-flash rust agent;

[0119] Calculated by weight percentage, the curing agent component B includes: 22% of modified fatty amine, 2.5% of auxiliary agent, 50% of filler B, 24% of solvent, 0.7% of anti-flash rust agent and 0.8% of wetting agent.

[0120] Example 4

[0121] On the basis of Examples 1-3, this example further defines the auxiliary agent to further illustrate the technical solution.

[0122] Among them, additives include dispersants, rheological additives and defoamers;

[0123] In terms of weight percentage, the main agent component A includes: 17% of base epoxy resin, 3% of hyperbranched polyester modified epoxy resin, 2% of dispersant, 2.5% of rheological additive, 1.5% of defoamer, 63% of filler A, 0.5% of wetting agent, 9.5% of solvent and 1% of flash rust inhibitor;

[0124] In terms of weight percentage, curing agent component B includes: 25% modified fatty amine, 1.5% dispersant, 0.5% rheological additive, 1.5% defoamer, 48% filler B, 22.5% solvent, 0.5% flash rust inhibitor and 0.5% wetting agent.

[0125] Example 5

[0126] On the basis of Examples 1-3, this example further defines filler A and filler B to further illustrate this technical solution.

[0127] Wherein, filler A includes talc powder, silica powder and precipitated barium sulfate, and filler B includes talc powder and silica powder;

[0128] In terms of weight percentage, the main agent component A includes: 17% of base epoxy resin, 3% of hyperbranched polyester modified epoxy resin, 6% of auxiliary agent, 29% of talc powder, 29% of silica powder, 5% of precipitated barium sulfate, 0.5% of wetting agent, 9.5% of solvent and 1% of flash rust inhibitor;

[0129] Calculated by weight percentage, the curing agent component B includes: 25% of modified fatty amine, 3.5% of auxiliary agent, 23% of talc powder, 23% of silica powder, 24.5% of solvent, 0.5% of anti-flash rust agent and 0.5% of wetting agent.

[0130] Example 6

[0131] On the basis of Examples 1-3, this example further defines the solvent to further illustrate the technical solution.

[0132] Solvents include aqueous cosolvents and purified water;

[0133] In terms of weight percentage, the main agent component A includes: 17% of base epoxy resin, 3% of hyperbranched polyester modified epoxy resin, 6% of auxiliary agent, 63% of filler A, 0.5% of wetting agent, 4.5% of aqueous cosolvent, 5% of purified water and 1% of flash rust inhibitor;

[0134] Calculated by weight percentage, the curing agent component B includes: 25% of modified fatty amine, 3.5% of auxiliary agent, 48% of filler B, 3% of aqueous cosolvent, 19.5% of purified water, 0.5% of anti-flash rust agent and 0.5% of wetting agent.

[0135] Example 7

[0136] This embodiment provides: a modified epoxy water-based putty suitable for rail transit vehicles, which is light green and includes a main agent component A and a curing agent component B, wherein the weight ratio of the main agent component A to the curing agent component B is 2:1;

[0137] Wherein, in terms of weight percentage, the main agent component A comprises:

[0138] E-51 epoxy resin (base epoxy resin) 20%, hyperbranched polyester modified epoxy resin 5%, DISPERBYK-199BF dispersant 3%, Ito T-550F rheological additive 5%, BYK-011 defoamer 3%, titanium dioxide 5%, talc 20%, silica fume 23.5%, precipitated barium sulfate 4%, water-based color paste 1.5%, functional nanomaterial 2%, BYK-346 wetting agent 0.5%, dipropylene glycol butyl ether DPNB water-based cosolvent 3%, purified water 3%, and Halox Flash-x-150 water-based flash rust inhibitor 1.5%;

[0139] Wherein, in terms of weight percentage, the curing agent component B comprises:

[0140] Modified fatty amine 20%, DISPERBYK-199BF dispersant 1%, Ito T-550F rheological additive 1%, BYK-011 defoamer 2%, talc 30%, silica powder 30%, dipropylene glycol butyl ether DPNB aqueous cosolvent 3%, Halox Flash-x-150 aqueous anti-flash rust agent 0.5%, BYK-346 wetting agent 1% and purified water 11.5%.

[0141] In addition, the titanium dioxide content in the titanium dioxide is ≥90%; the whiteness of the coated type is ≥98% compared with the standard sample; the average particle size is ≤0.3μm;

[0142] The water-based color paste is BASF L8730 phthalocyanine green-water paste, wherein the content of BASF L8730 phthalocyanine green is 40%, and the fineness is ≤10μm;

[0143] Functional nanomaterials (such as Figure 3 ) is a mixture of nano-ceramic powder aqueous solution and chelating water-based coupling agent TM-200S, with a weight ratio of the two being 4:1.

[0144] Example 8

[0145] This embodiment provides: a modified epoxy water-based putty suitable for rail transit vehicles, which is light green and includes a main agent component A and a curing agent component B, wherein the weight ratio of the main agent component A to the curing agent component B is 3:2;

[0146] Wherein, in terms of weight percentage, the main agent component A comprises:

[0147] CYD-128 epoxy resin (Yueyang Baling Petrochemical, base epoxy resin) 16%, hyperbranched polyester modified epoxy resin 2%, DISPERBYK-2012 dispersant 1%, AEROSIL R972 rheology additive 2%, BYK-022 defoamer 1%, titanium dioxide 3%, talc 28%, silica fume 28%, precipitated barium sulfate 3%, water-based color paste 1%, functional nanomaterial 1%, BYK-348 wetting agent 0.7%, propylene glycol methyl ether acetate (PMA) water-based cosolvent 3%, purified water 9%, and Halox Flash-x-150 water-based flash rust inhibitor 1.3%.

[0148] Wherein, in terms of weight percentage, the curing agent component B comprises:

[0149] Modified fatty amine 30%, DISPERBYK-2012 dispersant 2%, AEROSIL R972 rheology additive 1%, BYK-022 defoamer 3%, talc 20%, silica powder 20%, propylene glycol methyl ether acetate PMA aqueous cosolvent 5%, HaloxFlash-x-150 water-based flash rust inhibitor 0.5%, BYK-348 wetting agent 0.5% and purified water 18%.

[0150] In addition, the titanium dioxide content in the titanium dioxide is ≥90%; the whiteness of the coated type is ≥98% compared with the standard sample; the average particle size is ≤0.3μm;

[0151] The water-based color paste is BASF L8730 phthalocyanine green-water paste, wherein the content of BASF L8730 phthalocyanine green is 40%, and the fineness is ≤10μm;

[0152] The functional nanomaterial is a mixture of nano-ceramic powder aqueous solution and chelating water-based coupling agent TM-200S, with a weight ratio of the two being 6:1.

[0153] Example 9

[0154] This embodiment provides: a modified epoxy water-based putty suitable for rail transit vehicles, which is light green and includes a main agent component A and a curing agent component B, wherein the weight ratio of the main agent component A to the curing agent component B is 5:2;

[0155] Wherein, in terms of weight percentage, the main agent component A comprises:

[0156] EPIKOTE828 epoxy resin (Hexion, USA, base epoxy resin) 17%, hyperbranched polyester modified epoxy resin 4%, Gen 1252 dispersant 2%, AEROSIL 380 rheology additive 3%, NOPCO NXZ defoamer 2%, titanium dioxide 4.4%, talc 26%, silica fume 26.7%, precipitated barium sulfate 4%, water-based color paste 1.3%, functional nanomaterial 2%, TEGO TWIN 4100 wetting agent 0.4%, diethylene glycol butyl ether DGB water-based cosolvent 3%, purified water 3%, and HaloxFlash-x-150 water-based flash rust inhibitor 1.2%;

[0157] Wherein, in terms of weight percentage, the curing agent component B comprises:

[0158] Modified fatty amine 25%, Gen 1252 dispersant 1.5%, AEROSIL 380 rheology additive 0.8%, NOPCO NXZ defoamer 2.2%, talc 25%, silica fume 25%, diethylene glycol butyl ether DGB aqueous cosolvent 4%, HaloxFlash-x-150 water-based flash rust inhibitor 0.7%, TEGO TWIN 4100 wetting agent 0.5% and purified water 15.3%.

[0159] In addition, the titanium dioxide content in the titanium dioxide is ≥90%; the whiteness of the coated type is ≥98% compared with the standard sample; the average particle size is ≤0.3μm;

[0160] The water-based color paste is BASF L8730 phthalocyanine green-water paste, wherein the content of BASF L8730 phthalocyanine green is 40%, and the fineness is ≤10μm;

[0161] The functional nanomaterial is a mixture of nano-ceramic powder aqueous solution and chelating water-based coupling agent TM-200S, with a weight ratio of 5:1.

[0162] Example 10

[0163] This embodiment provides: a modified epoxy water-based putty suitable for rail transit vehicles, which is light green and includes a main agent component A and a curing agent component B, wherein the weight ratio of the main agent component A to the curing agent component B is 2:1;

[0164] Wherein, in terms of weight percentage, the main agent component A comprises:

[0165] E-51 epoxy resin (base epoxy resin) 17%, hyperbranched polyester modified epoxy resin 3%, DISPERBYK-2012 dispersant 1%, AEROSIL R974 rheology additive 4%, TEGO Foamex 3062 defoamer 3%, titanium dioxide 5%, talc 24%, silica fume 23.6%, precipitated barium sulfate 6%, water-based color paste 1.4%, functional nanomaterial 1%, BYK-333 wetting agent 0.5%, diethylene glycol butyl ether DGB water-based cosolvent 4%, purified water 5%, and Halox Flash-x-150 water-based flash rust inhibitor 1.5%.

[0166] Wherein, in terms of weight percentage, the curing agent component B comprises:

[0167] Modified fatty amine 22%, DISPERBYK-2012 dispersant 1%, AEROSIL R974 rheology additive 0.5%, NOPCO NXZ defoamer 1.5%, talc 21.4%, silica fume 29%, dipropylene glycol butyl ether DPNB aqueous cosolvent 3%, Halox Flash-x-150 aqueous flash rust inhibitor 0.7%, TEGO TWIN 4100 wetting agent 0.9% and purified water 20%;

[0168] In addition, the titanium dioxide content in the titanium dioxide is ≥90%; the whiteness of the coated type is ≥98% compared with the standard sample; the average particle size is ≤0.3μm;

[0169] The water-based color paste is BASF L8730 phthalocyanine green-water paste, wherein the content of BASF L8730 phthalocyanine green is 40%, and the fineness is ≤10μm;

[0170] The functional nanomaterial is a mixture of nano-ceramic powder aqueous solution and chelating water-based coupling agent TM-200S, with a weight ratio of 5:1.

[0171] Example 11

[0172] This embodiment provides: a modified epoxy water-based putty suitable for rail transit vehicles, which is light green and includes the following components:

[0173] Formula of component A: E-51 epoxy resin 17%, HyPerE102 hyperbranched polyester modified epoxy resin 3%, DISPERBYK-199BF dispersant 2%, Ito T-550F rheological additive 2%, AEROSIL 380 rheological additive 0.5%, TEGO Foamex 3062 defoamer 1%, NOPCO NXZ defoamer 0.5%, titanium dioxide 5%, talc 25%, silica fume 25%, precipitated barium sulfate 5%, water-based color paste 1%, functional nanomaterial 2%, TEGO TWIN 4100 wetting agent 0.5%, PMA water-based cosolvent 4.5%, Halox Flash-x-150 water-based flash rust inhibitor 1% and purified water 5%;

[0174] Formula of component B: modified fatty amine TEPA-ATN (water-based) 25%, Gen 1252 dispersant 1.5%, AEROSIL R972 rheology additive 0.5%, TEGO Foamex 3062 defoamer 0.5%, NOPCO NXZ defoamer 1%, talc 23%, silica micropowder 23%, aqueous cosolvent PMA 2%, aqueous cosolvent DPNB 3%, Halox Flash-x-150 aqueous anti-flash rust agent 0.5%, BYK-346 wetting agent 0.5%, purified water 19.5%.

[0175] In addition, the titanium dioxide content in the titanium dioxide is ≥90%; the whiteness of the coated type is ≥98% compared with the standard sample; the average particle size is ≤0.3μm;

[0176] The water-based color paste is BASF L8730 phthalocyanine green-water paste, wherein the content of BASF L8730 phthalocyanine green is 40%, and the fineness is ≤10μm;

[0177] The functional nanomaterial is a mixture of nano-ceramic powder aqueous solution and chelating water-based coupling agent TM-200S, with a weight ratio of the two being 4:1.

[0178] Example 12

[0179] Based on Examples 7-11, this embodiment provides: a method for preparing a modified epoxy water-based putty suitable for rail transit vehicles, comprising the following steps:

[0180] 1. Preparation of main agent component A

[0181] The base epoxy resin and the hyperbranched polyester-modified epoxy resin are placed in a mixing kettle I and mixed uniformly; then, a dispersant is added and stirred until the mixture is uniformly mixed; while stirring, a rheological additive (anti-settling agent) and a defoamer are sequentially added and stirred until the mixture is uniformly mixed (approximately 5-10 minutes to establish an effective anti-settling system); finally, titanium dioxide is added and mixed uniformly under high-speed dispersion conditions of 1000-1200 r / min to obtain a coarse suspension without particles;

[0182] The obtained coarse suspension is conveyed to a sand mill and ground to a fineness of ≤20 μm to obtain a titanium dioxide slurry; then, the suspension is put into a mixing kettle II, and talc powder, silica powder and precipitated barium sulfate are added to the titanium dioxide slurry at a high speed of 1000-1200 r / min to disperse the slurry to a fineness of ≤100 μm, and the speed is reduced to 600-800 r / min; while stirring, functional nanomaterials, aqueous cosolvents, flash rust inhibitors and wetting agents are added in sequence, and stirred to form a uniform paste (about 20 minutes), and ground to a fineness of ≤50 μm by a three-roll grinder I to obtain component A (such as Figure 4 );

[0183] Testing, use pure water to adjust the consistency of component A to 13-15;

[0184] 2. Preparation of curing agent component B

[0185] Add the modified fatty amine (modified curing agent) into the mixing kettle III, add the dispersant while stirring, and stir evenly; add the rheological additive (anti-settling agent) and defoamer in sequence while stirring, and stir until the mixture is evenly mixed (about 5-10 minutes; to establish an effective anti-settling system); add talcum powder, silica powder and water-based color paste at a high-speed dispersion speed of 1000-1200 r / min, and disperse to a fineness of ≤100 μm; reduce the speed to 600-800 r / min, and add the water-based cosolvent, anti-flash rust agent, wetting agent and purified water (about 60% of the total volume) while stirring until a uniform paste is formed, and grind it to a fineness of ≤50 μm in a three-roll mill II to obtain component B (such as Figure 5 );

[0186] Testing, use purified water to adjust the consistency of component B to 12-14;

[0187] 3. Preparation of modified epoxy water-based putty

[0188] When using, mix component A and component B according to the weight ratio (such as 2:1) and stir evenly to obtain modified epoxy water-based putty.

[0189] In the above preparation method, the uniform paste formed is ground by a three-roll grinder. On the one hand, it can realize physical degassing, facilitate subsequent painting use, and indirectly ensure that the putty is easy to scrape; the putty is scraped no more than 1.0mm at a time, and pores are not easy to form on the surface of the putty film (observe after grinding); on the other hand, it is to improve the fineness of the putty and ensure that the putty film formed by scraping is smooth and delicate, and easy to scrape; in addition, it also effectively improves production efficiency (three-roll grinder grinding, after 10-20min, the component fineness can be achieved ≤50μm), the putty fineness is easy to achieve; and it is not easy to produce sedimentation. After storage, there is no clear liquid on the upper layer, which is uniform and consistent, and thus better suitable for the painting of rail transit vehicles.

[0190] Example 13

[0191] Based on Examples 1-11, the modified epoxy water-based putty obtained in this example was subjected to product performance testing. The product indicators of the modified epoxy water-based putty include: surface drying time ≤ 2h (25°C), through drying time ≤ 24h / 25°C, anti-sag thickness ≥ 5mm, pencil hardness ≥ H, adhesion (cross-hatch method) level 0, thixotropic index > 3.5; sandability: easy to sand, easy to dust, and non-sticky to sandpaper;

[0192] Coating and scraping properties: easy to apply and scrape (smooth and free when applying, no sticking to the knife), no curling phenomenon;

[0193] Drying property: Mix the main agent component A and the curing agent component B evenly, dry thoroughly at room temperature (15-30℃) for 24 hours, and test according to GB1728-79 standard;

[0194] Adhesion: Strong adhesion to metal or base coating (cross-hatch test or cross-hatch test level 1 or above, tested according to GB / T31586.2 standard; pull-off adhesion ≥ 4.0MPa, tested according to GB / T 5210 standard). Figure 7-8 As shown;

[0195] Sandability: easy to sand, non-sticky to sandpaper, no obvious white spots, tested according to GB / T 1748 standard; during the sandability test, the coating is smoothed with sandpaper. Finally, the sandability of the putty is judged based on the amount of powder ground out per minute and the difficulty of grinding;

[0196] Flexibility (cylindrical shaft): ≤50mm, tested according to GB / T 1748 standard;

[0197] Impact resistance: ≥15cm, tested according to GB / T 1732 standard;

[0198] Water resistance test: 24h water absorption line is no more than 1mm above the horizontal surface, no swelling or softening, tested according to GB / T 1733 standard;

[0199] Composite coating performance (salt spray performance, etc.) test panels are prepared as follows: The composite coating consists of primer, putty, midcoat, and topcoat. Panels are applied sequentially, with at least 16 hours between each coat, and at least 24 hours between primer and putty. The coating is dried naturally or force-dried. Forced drying conditions include: 1.5-2 hours after spraying, followed by baking at 60±2°C for 2 hours. The primer dry film thickness is 70±5μm, the scraped putty thickness is 3-5mm, and the water-sandblasting thickness is controlled to 450±50μm. The midcoat dry film thickness is 30±5μm. The topcoat is either a medium-grey solid topcoat (50±5μm) or a basecoat (20±5μm) plus a clearcoat (50±5μm), for a total of 70±5μm. Force-dried panels are then left to dry naturally for 7 days before testing performance.

[0200] Example 14

[0201] On the basis of Examples 1-11, this Example uses the obtained modified epoxy water-based putty for painting rail transit vehicles, that is, provides: a painting process for rail transit vehicles.

[0202] The painting process of rail transit vehicles is a complex process involving multiple steps and specific technologies to ensure the quality and durability of the vehicle surface. Figure 6 、 Figure 11 ) The coating process involved includes:

[0203] 1. Pre-treatment: Before painting, the surface (substrate) of the vehicle needs to be cleaned and treated to ensure good adhesion of the coating. This usually includes cleaning the shell and phosphating treatment;

[0204] 2. Primer coating: It is an important part of the coating process, which provides anti-corrosion protection and provides good adhesion for subsequent coatings. In rail transit vehicle coating, anti-rust primer is usually used;

[0205] 3. Filling with modified epoxy water-based putty: After the primer has dried, use this modified epoxy water-based putty to fill in minor surface defects and unevenness. This means applying 2-3 coats of putty, patching leaks, and smoothing the surface. This step helps improve the smoothness and aesthetics of the final coating.

[0206] 4. Mid-coat: Mid-coat is used to further enhance the adhesion and durability of the coating, and can also help improve the appearance of the coating. Mid-coat is usually sprayed in a dust-free workshop to avoid contamination.

[0207] 5. Topcoat spraying: The topcoat is the last layer in the painting process, which determines the final color and appearance of the vehicle. The topcoat needs to have good weather resistance and corrosion resistance to ensure the appearance and performance of the vehicle in long-term use. Among them, the solid color topcoat is (50±5)μm or the base paint is (20±5)μm + the clear paint is (50±5)μm, totaling (70±5)μm;

[0208] 6. Drying: After each coating is sprayed, the vehicle needs to enter the drying room for drying to ensure that the coating can be properly cured and achieve the required physical properties.

[0209] The main purpose of using this modified epoxy water-based putty for painting rail transit vehicles is:

[0210] 1. Sealing the substrate: This modified epoxy water-based putty first forms a dense film through the interaction between its particles and the adhesion with the substrate, effectively sealing the substrate and preventing the intrusion of foreign substances;

[0211] 2. Filling and repairing: With its good fluidity and filling properties, this modified epoxy water-based putty can penetrate into the tiny gaps and holes of the substrate, fill these defects through the drying or curing process, and restore the smoothness of the substrate surface;

[0212] 3. Enhanced adhesion: The special ingredients in the modified epoxy water-based putty can form chemical bonds or physical adsorption with the surface of the substrate, enhancing the bonding force between the putty layer and the substrate, providing a solid foundation for the adhesion of subsequent coatings;

[0213] 4. Provide protection: The modified epoxy water-based putty layer after drying or curing has a certain hardness (HB or above) and toughness (bending 50cm), which can resist a certain degree of mechanical wear and chemical corrosion and protect the substrate from damage;

[0214] 5. Adjustment and beautification: By adjusting the formula and construction process of water-based epoxy putty, the putty layer can present different textures and colors, thereby achieving the effect of adjusting and beautifying the surface of the substrate to meet actual needs.

[0215] In summary, the working principle of this modified epoxy water-based putty is to achieve the functions of sealing, filling, enhancing adhesion, protecting and beautifying the substrate through its unique chemical and physical properties (specific performance).

[0216] The painting process for rail transit vehicles includes pretreatment, primer application, putty filling, mid-coat, topcoat spraying, and drying. Each step has its own specific purpose and technical requirements to ensure the quality and environmental compliance of the final product. Specifically, by adopting specific putty formulations and matching painting techniques, painting efficiency can be effectively improved, environmental pollution can be reduced, and the service life of the vehicle can be extended.

[0217] Example 15

[0218] Based on Example 13, this embodiment provides: a preparation system for a modified epoxy water-based putty, such as Figure 13 As shown, it includes a main agent component preparation unit 1 and a curing agent component preparation unit 2, wherein,

[0219] Main agent component preparation unit 1: includes mixing kettle I 101, sand mill 102, mixing kettle II 103 and three-roll grinder I 104, mixing kettle I 101 is connected with substrate epoxy resin feed pipe 105, hyperbranched polyester modified epoxy resin feed pipe 106, rheological additive feed pipe I 107, defoamer feed pipe I 108 and titanium dioxide feed pipe I 109, mixing kettle I 101 is arranged in front of the station of sand mill 102, and the upper discharge port of mixing kettle I 101 is connected to the upper feed port of sand mill 102; mixing kettle II 103 is provided at the rear side of the station of sand mill 102, and the upper discharge port of sand mill 102 is connected to the upper feed port of mixing kettle II 103; mixing kettle II 103 is connected A talcum powder feed pipe I110, a silicon micropowder feed pipe I111, a precipitated barium sulfate feed pipe I112, a water-based color paste feed pipe 113, and an auxiliary agent feed pipe I114 are provided. A three-roll grinder I104 is provided at the rear side of the mixing kettle II 103, and the upper discharge port of the mixing kettle II 103 is connected to the upper feed port of the three-roll grinder I104; a main agent component temporary storage tank 3 is provided at the rear side of the three-roll grinder I104, and the upper discharge port of the three-roll grinder I104 is connected to the upper feed port of the main agent component temporary storage tank 3; a continuous passage for continuous preparation and temporary storage of the main agent component is formed between the mixing kettle I101, the sand mill 102, the mixing kettle II 103, the three-roll grinder I104, and the main agent component temporary storage tank 3;

[0220] Curing agent component preparation unit 2: includes mixing kettle III 201 and three-roll mill II 202. Mixing kettle III 201 is connected to modified fatty amine feed pipe 203, rheological agent feed pipe II 204, defoaming agent feed pipe II 205, talc powder feed pipe II 206, silicon micropowder feed pipe II 207 and auxiliary agent feed pipe II 208. Mixing kettle III 201 is arranged in front of the workstation of three-roll mill II 202, and the upper discharge port of mixing kettle III 201 is connected to the upper feed port of three-roll mill II 202; a curing agent component temporary storage tank 4 is provided on the rear side of the workstation of three-roll mill II 202, and the upper discharge port of three-roll mill II 202 is connected to the upper feed port of curing agent component temporary storage tank 4; a continuous passage for continuous preparation and temporary storage of curing agent components is formed between mixing kettle III 201, three-roll mill II 202 and curing agent component temporary storage tank 4.

[0221] This embodiment realizes the preparation of two components in putty products through the specific setting and arrangement of the equipment in the main component preparation unit 1 and the curing agent component preparation unit 2. On the one hand, it ensures the stability of the performance of each component to meet actual needs; on the other hand, it ensures the stability of the batch quality of the two components in the modified epoxy water-based putty to achieve industrial and large-scale production.

[0222] This embodiment further defines the structures of mixing kettles I 101, II 103, and III 201: Each of these is equipped with a stirring mechanism comprising an agitator and a stirring motor. The agitator is connected to the stirring motor, which is then connected to a PLC control system via a frequency converter. This configuration allows for control of the stirring mechanism's speed within each mixing kettle, facilitating the addition and uniform mixing of materials.

[0223] This embodiment further defines the structure of the sand mill 102: the sand mill 102 is a horizontal sand mill. This configuration, when used with a coarse suspension having viscosity, can achieve continuous grinding and ensure grinding fineness, thereby facilitating subsequent control of the fineness of the main agent component.

[0224] In order to improve the orderliness and continuity of material feeding during the preparation of the main component, this embodiment further defines: the mixing kettle I 101 is connected to the substrate epoxy resin storage tank 6 through the substrate epoxy resin feeding pipe 105, is connected to the hyperbranched polyester modified epoxy resin storage tank 7 through the hyperbranched polyester modified epoxy resin feeding pipe 106, is connected to the rheological agent storage tank 8 through the rheological agent feeding pipe I 107, and is connected to the defoaming agent storage tank through the defoaming agent feeding pipe I 108. 9. It is connected to the titanium dioxide storage tank 10 through the titanium dioxide feed pipe I109; the mixing kettle II 103 is connected to the talc powder storage tank 11 through the talc powder feed pipe I110, is connected to the silicon powder storage tank 12 through the silicon powder feed pipe I111, is connected to the precipitated barium sulfate storage tank 13 through the precipitated barium sulfate feed pipe I112, is connected to the aqueous color paste storage tank 14 through the aqueous color paste feed pipe 113, and is connected to the additive storage tank I15 through the additive feed pipe I114.

[0225] In order to improve the orderliness and continuity of material feeding during the preparation of the curing agent component, this embodiment further defines: the mixing kettle III 201 is connected to the modified fatty amine storage tank 16 through the modified fatty amine feed pipe 203, is connected to the rheological additive storage tank 8 through the rheological additive feed pipe II 204, is connected to the defoaming agent storage tank 9 through the defoaming agent feed pipe II 205, is connected to the talc powder storage tank 11 through the talc powder feed pipe II 206, is connected to the silicon micropowder storage tank 12 through the silicon micropowder feed pipe II 207, and is connected to the additive storage tank II 17 through the additive feed pipe II 208.

[0226] Application Examples

[0227] On the basis of Example 11, the obtained modified epoxy water-based putty was used to coat rail transit vehicles produced by a locomotive factory in Ziyang and a vehicle factory in Chengdu;

[0228] It was found that the modified epoxy water-based putty has good bonding properties, can be firmly attached to the substrate or primer, and is not easy to fall off. Its fine quality makes the putty film surface smoother, reducing the workload of subsequent grinding; and during the construction process, there is little odor (no foul smell) and no irritating odor (0 formaldehyde content, such as Figure 9-10 shown);

[0229] Coating effect: uniform color, smooth paint film, and better coating effect;

[0230] Composite coating performance: Adhesion is cross-graded to level 0, water resistance has no significant change after 240 hours, and salt spray resistance has passed the 1000-hour test.

[0231] Discuss Example 1-7

[0232] Based on Example 11, this discussion uses HyPerE102 hyperbranched polyester-modified epoxy resin and E-51 epoxy resin to discuss the addition amount of the hyperbranched polyester-modified epoxy resin and the ratio between the base epoxy resin and the hyperbranched polyester-modified epoxy resin. This further illustrates the effects of the addition amount of the hyperbranched polyester-modified epoxy resin and the ratio between the base epoxy resin and the hyperbranched polyester-modified epoxy resin on the performance of the putty product. The details are shown in Table 2.

[0233] Table 2

[0234]

[0235]

[0236] The results showed that when the addition amount of HyPerE102 hyperbranched polyester modified epoxy resin was 7-12% (the total resin content in the putty, total resin = E-51 addition + HyPerE102 addition + modified curing agent addition), the putty product had good performance; and when the weight ratio of E-51 epoxy resin:HyPerE102 hyperbranched polyester modified epoxy resin was 4.2-8.2:1, the putty product had excellent overall performance.

[0237] In addition, different amounts of hyperbranched polyester modified epoxy resin were added to prepare putty, and the cross-sectional morphology of the formed cured product samples was scanned. The results are shown in Figure 2. Figure 12As shown in the figure, the impact cross-section of the cured sample without hyperbranched polyester resin is relatively smooth, with sharp corners at the end. The stress generated after fracture is uniform in direction, with no stress dispersion, indicating brittle fracture. However, as the content of hyperbranched polyester-modified epoxy resin increases, the impact cross-section of the cured sample becomes smoother and rougher, with blurred cross-section boundaries and a more dispersed fracture direction. This is consistent with the experimental results of the impact strength, pull-off adhesion, and flexibility of the paint film. Furthermore, morphological observations show no two-phase structure in the cured sample, indicating that the carboxyl-terminated hyperbranched polyester is uniformly dispersed within the epoxy resin cross-linked network.

[0238] Discussion Example 8

[0239] Based on Example 11, this discussion uses HyPerE102 hyperbranched polyester-modified epoxy resin and E-51 epoxy resin. The addition amount of the hyperbranched polyester-modified epoxy resin, the addition amount of the base epoxy resin, and the ratio between the two are discussed to further illustrate the impact of resin system balance on the subsequent putty film performance. The details are shown in Table 3.

[0240] Table 3

[0241]

[0242]

[0243] It can be seen that a weight ratio of 1:5-6 for the hyperbranched polyester-modified epoxy resin HyPerE102 to the base epoxy resin E-51 effectively ensures the pull-off adhesion and hardness of the putty film. When the addition level of the hyperbranched polyester-modified epoxy resin HyPerE102 exceeds 3%, the addition level of the base epoxy resin E-51 must be simultaneously increased to above 18% to avoid a decrease in mechanical strength. Furthermore, considering all factors, the total addition level of the hyperbranched polyester-modified epoxy resin HyPerE102 and the base epoxy resin E-51 should be between 15-25% to ensure the performance of the putty film while also meeting composite environmental requirements.

[0244] Discussion Example 9

[0245] Based on Example 11, this discussion uses the hydroxy hyperbranched polyester Boltorn TM H2004 modified epoxy resin (Perstorp), carboxyl-terminated hyperbranched polyester modified epoxy resin HyPerC100 (Wuhan Hyperbranched Resin Technology Co., Ltd.), hydroxyl-terminated hyperbranched polyester modified epoxy resin HyPerE104 (Wuhan Hyperbranched Resin Technology Co., Ltd.), carboxyl-terminated hyperbranched polyester modified epoxy resin HyPerE102 (Wuhan Hyperbranched Resin Technology Co., Ltd.), AGE epoxy resin reactive diluent (C 12-14-alkyl glycidyl ether, CAS number: 68609-97-2; supplier: Guangzhou Yuebao Chemical Technology Co., Ltd., manufacturer: Hubei Green Home Materials Technology Co., Ltd.; model: LS-AGE), carboxyl-terminated hyperbranched polyester modified epoxy resin EHC 1261 (supervised by Beijing Institute of Chemical Technology, produced by Tianjin Jinjiuqiang New Materials Co., Ltd.), were used to prepare modified epoxy waterborne putty, and the results were as follows: Figure 4 As stated;

[0246] Table 4

[0247]

[0248] It can be seen that: 1. Hydroxyl hyperbranched polyester Boltorn TM H2004, hydroxyl-terminated hyperbranched polyester modified epoxy resin HyPerE104, and AGE epoxy resin reactive diluent have good miscibility with E-51 epoxy resin, but cannot form a cross-linked whole with the epoxy system after cross-linking and curing, resulting in poor adhesion and bending properties of the putty products prepared separately;

[0249] Second, the carboxyl-terminated hyperbranched polyester modified epoxy resin HyPerC100 has good miscibility with E-51 epoxy resin. However, due to the slightly poor flexibility of HyPerC100, the main properties of the prepared putty product basically meet the technical requirements, but the bending and impact properties are slightly poor.

[0250] 3. The putty products prepared using end-carboxyl hyperbranched polyester modified epoxy resin HyPerE102 (Wuhan Hyperbranched Resin Technology Co., Ltd.) and hyperbranched polyester modified epoxy resin EHC 1261 (supervised by Beijing Institute of Chemical Technology and produced by Tianjin Jinjiuqiang New Materials Co., Ltd.) have excellent performance, and the prices involved meet the cost requirements of putty products; and the use of end-carboxyl hyperbranched polyester modified epoxy resin provides excellent processing performance and bonding strength for putty coating, thereby improving the adhesion and durability of the coating.

[0251] Discussion Example 10

[0252] Based on Example 11, this discussion discusses the ratio between talc powder and silica powder in the filler system to further illustrate the impact of the filler system balance on the subsequent putty film performance. Specifically, it includes:

[0253] 1. Theoretical analysis of improving bulk density by bimodal particle size distribution design (talc powder D50 = 15μm, silica powder D50 = 5μm)

[0254] 1. Bimodal stacking mold

[0255] The bimodal particle size distribution increases bulk density through the synergistic effect of large particles (talc) and small particles (silica powder):

[0256] Function of large particle skeleton: Talc (D50 = 15 μm) forms the main skeleton and occupies most of the volume;

[0257] Small particle filling effect: Silica powder (D50 = 5 μm) fills the gaps between talc powders and reduces the pore volume;

[0258] 2. Particle size ratio optimization

[0259] According to Furnas stacking theory, when the diameter of small particles (d 小 ) and the diameter of the largest particle (d 大 ) satisfies d 小 / d 大 When ≤0.22, efficient filling can be achieved. In this discussion:

[0260] d 硅微粉 ÷d 滑石粉 =5÷15≈0.33

[0261] Although slightly higher than the theoretical value, it can still be effectively filled through the vibration compaction process (the actual particle size distribution has a certain width);

[0262] 3. Single component testing

[0263] The bulk density, tap density and porosity of talc and silica powder were measured respectively;

[0264] 4. Two-component mixing test

[0265] Talc powder and silica powder were mixed in a mass ratio (e.g., 70:30, 50:50, 30:70), and the bulk density, tap density, and porosity were tested. The results are shown in Table 5 below.

[0266] Table 5

[0267] sample <![CDATA[Apparent density (g / cm 3 )]]> <![CDATA[Tap density (g / cm 3 )]]> Void ratio (%) Pure talc 0.85 1.20 45.2(2.18) Pure silicon powder 0.65 0.95 53.8(2.06) Talc:silica powder=70:30 1.10 1.55 33.5(2.33) Talc:silica powder=50:50 1.25 1.75 28.9(2.43) Talc:silica powder=30:70 1.15 1.60 31.2(2.33)

[0268] It can be seen that when the mixing ratio is 50:50, the tap density is the highest (1.75g / cm 3 ), the porosity is the lowest (28.9%); and compared with the single component talc powder / silica powder, the porosity is significantly improved.

[0269] Furthermore, the performance tests of the formed putty films were carried out respectively, and the obtained results are shown in Table 6 below;

[0270] Table 6

[0271]

[0272]

[0273] In summary, it can be seen that the optimal mass ratio between talc powder and silica powder is 1:1 (e.g. 25% talc powder + 25% silica powder), and the bimodal particle size distribution design (talc powder D 50 =15μm, silicon powder D 50 =5μm) can increase the bulk density. The increase in bulk density is directly reflected in the improvement of the adhesion of the putty film.

[0274] Discussion Example 11

[0275] Based on Example 11, this discussion discusses the ratio of rheological additives in the anti-sagging system to further illustrate the impact of the balance of the anti-sagging system on the subsequent putty film performance. Specifically, it includes:

[0276] 1. The significance of thixotropic index (TI value)

[0277] The Thixotropic Index (TI) is a key indicator for evaluating the thixotropy of non-Newtonian fluids (such as coatings and adhesives). It is defined as the ratio of the apparent viscosity measured at low speed to the apparent viscosity at high speed (unitless). Its significance lies in:

[0278] a. Reflects the structural recovery ability of the material: The higher the TI value, the less structural damage the material will suffer after shear force (such as stirring or painting), and the stronger its ability to recover its original structure when left standing. This is crucial for the putty's anti-sag, anti-diffusion, and anti-stretching properties after application;

[0279] b. Guidance on application performance: If the putty TI value is greater than 3.5, it indicates good fluidity (low viscosity) during construction, but quickly recovers to high viscosity after shearing stops, preventing the putty layer from being too thin or sagging. It is suitable for vertical surface spraying, precision dispensing, and other scenarios;

[0280] 2. The mass ratio of T-550F rheological additive to AEROSIL 380 rheological additive in the anti-sagging system was discussed. The results are shown in Table 7 below.

[0281] Table 7

[0282]

[0283]

[0284] It can be seen that when the mass ratio of T-550F rheological additive to AEROSIL 380 rheological additive is 1:0.3 (as shown in the table, 2% + 0.6%), the thixotropic index (TI value) is greater than 3.6 (>3.5, testing conditions: Brookfield viscometer, speed 6 / 60 rpm), the putty has good anti-sag performance, moderate consistency, and the best overall performance balance.

[0285] Discussion Example 12

[0286] Based on Example 12, this discussion example is as follows: In the preparation process of the modified epoxy water-based putty, for the preparation of the main agent component A and / or the curing agent component B, a three-roll mill is not used for grinding, but the formed uniform paste is directly stirred at a high speed (1000-1200 r / min) to a fineness of ≤50 μm;

[0287] It was found that: the stirring time was greater than 2h, i.e. the production efficiency was low; even if the fineness of the components was ≤50μm, the obtained putty was easy to settle, and there was a clear liquid on the upper layer after storage; in addition, the putty film obtained after coating was relatively rough and difficult to apply evenly; and, after the putty was applied more than 0.5mm at a time, pores were prone to appear on the surface of the putty film formed (observed after polishing).

[0288] Discussion Example 13

[0289] On the basis of Example 12, this discussion example is: in the preparation process of the modified epoxy water-based putty, the prepared main agent component A and / or curing agent component B are subjected to a defoaming treatment at a vacuum degree of 0.02 MPa for 4-6 hours before being put into use;

[0290] It was found that: compared with the case where no vacuum defoaming treatment was performed (Example 11), the sedimentation property, easy coating property and foaming property of the putty product did not change, but the production cost involved was increased.

[0291] The above description is only a preferred embodiment of the present invention and does not limit the present invention in any form. Any simple modification or equivalent change made to the above embodiment based on the technical essence of the present invention shall fall within the scope of protection of the present invention.

Claims

1. A modified epoxy water-based putty suitable for rail transit vehicles, characterized in that: It comprises a main agent component A and a curing agent component B, wherein the weight ratio of the main agent component A to the curing agent component B is 3-5:2; The main agent component A comprises, by weight percentage, 15-20% of base epoxy resin, 2-5% of hyperbranched polyester modified epoxy resin, 4-11% of auxiliary agent, 40-65% of filler A, 0.3-0.7% of wetting agent, 6-14% of solvent and 0.8-1.5% of anti-flash rust agent; In terms of weight percentage, the curing agent component B includes: modified fatty amine 20-30%, additive 2.5-6%, filler B 40-60%, solvent 13-25%, anti-flash rust agent 0.5-1% and wetting agent 0.5-1%; The product indicators of the modified epoxy water-based putty include: surface drying time ≤2h at 25°C, actual drying time ≤24h at 25°C, anti-sag thickness ≥5mm, pencil hardness ≥H, adhesion level 0, thixotropic index >3.5, pull-off adhesion ≥4.0MPa, flexibility ≤50mm, and impact resistance ≥15cm.

2. The modified epoxy water-based putty suitable for rail transit vehicles according to claim 1, characterized in that: The additives include dispersants, rheological additives and defoamers; In terms of weight percentage, the main agent component A includes: 15-20% of base epoxy resin, 2-5% of hyperbranched polyester modified epoxy resin, 1-3% of dispersant, 2-5% of rheological additive, 1-3% of defoamer, 40-65% of filler A, 0.3-0.7% of wetting agent, 6-14% of solvent and 0.8-1.5% of anti-flash rust agent; In terms of weight percentage, the curing agent component B includes: 20-30% of modified fatty amine, 1-2% of dispersant, 0.5-1% of rheological additive, 1-3% of defoamer, 40-60% of filler B, 13-25% of solvent, 0.5-1% of anti-flash rust agent and 0.5-1% of wetting agent.

3. The modified epoxy water-based putty suitable for rail transit vehicles according to claim 1, characterized in that: The filler A comprises talc, silica powder and precipitated barium sulfate, and the filler B comprises talc and silica powder; In terms of weight percentage, the main agent component A includes: 15-20% of base epoxy resin, 2-5% of hyperbranched polyester modified epoxy resin, 4-11% of auxiliary agent, 20-30% of talc powder, 20-30% of silica powder, 3-7% of precipitated barium sulfate, 0.3-0.7% of wetting agent, 6-14% of solvent and 0.8-1.5% of anti-flash rust agent; Calculated by weight percentage, the curing agent component B includes: 20-30% of modified fatty amine, 2.5-6% of auxiliary agent, 20-30% of talc powder, 20-30% of silicon powder, 13-25% of solvent, 0.5-1% of anti-flash rust agent and 0.5-1% of wetting agent.

4. The modified epoxy water-based putty suitable for rail transit vehicles according to claim 1, characterized in that: The solvent includes an aqueous cosolvent and purified water; In terms of weight percentage, the main agent component A includes: 15-20% of base epoxy resin, 2-5% of hyperbranched polyester modified epoxy resin, 4-11% of auxiliary agent, 40-65% of filler A, 0.3-0.7% of wetting agent, 3-5% of aqueous cosolvent, 3-9% of purified water and 0.8-1.5% of anti-flash rust agent; Calculated by weight percentage, the curing agent component B includes: 20-30% of modified fatty amine, 2.5-6% of auxiliary agent, 40-60% of filler B, 3-5% of aqueous cosolvent, 10-20% of purified water, 0.5-1% of anti-flash rust agent and 0.5-1% of wetting agent.

5. The modified epoxy water-based putty suitable for rail transit vehicles according to any one of claims 1 to 4, characterized in that: The base epoxy resin is E-51 epoxy resin, CYD-128 epoxy resin or EPIKOTE828 epoxy resin.

6. The modified epoxy water-based putty suitable for rail transit vehicles according to claim 5, characterized in that: The hyperbranched polyester modified epoxy resin is a carboxyl-terminated hyperbranched polyester modified epoxy resin with a molecular weight of 3200-3600 g / mol, an epoxy value of 0.20-0.25 mol / 100 g, a solid content of ≥99%, a VOC of ≤1.0%, and a viscosity of 500-700 cp; Hyperbranched polyester modified epoxy resin is C6H3 (CO2CH2CH2CO2C6H3) n (CO2C2H3O) m , wherein n is 8-12, and m is 12-18; the structural formula involved is as follows: 。 7. The modified epoxy water-based putty suitable for rail transit vehicles according to claim 5, characterized in that: The hyperbranched polyester modified epoxy resin HyPerE102 or the hyperbranched polyester modified epoxy resin EHC 1261.

8. The modified epoxy water-based putty suitable for rail transit vehicles according to any one of claims 1 to 4, characterized in that: The wetting agent is one of BYK-346, BYK-348, BYK-333 and TEGO TWIN 4100, or a mixture of any two or more thereof.

9. The modified epoxy water-based putty suitable for rail transit vehicles according to any one of claims 1 to 4, characterized in that: The modified fatty amine is acrylonitrile modified fatty amine, with a solid content of ≥99%, an amine value of 145-185 mg KOH / g, and a viscosity of 800-1600 mPa.s / 25°C.

10. The modified epoxy water-based putty suitable for rail transit vehicles according to any one of claims 1 to 4, characterized in that: The modified fatty amine is JJQ-WAE-B01 or Kingcure 690.

11. The modified epoxy water-based putty suitable for rail transit vehicles according to claim 2, characterized in that: The dispersant is one of DISPERBYK-199 BF, DISPERBYK-2012 and Borchi® Gen 1252, or a mixture of any two or more thereof; The rheological additive is one of Ito T-550F, AEROSIL R972, AEROSIL R974 and AEROSIL 380, or a mixture of any two or more thereof; The defoaming agent is one of BYK-011, BYK-022, TEGO Foamex 3062 and NOPCO NXZ, or a mixture of any two or more thereof.

12. The modified epoxy water-based putty suitable for rail transit vehicles according to claim 3, characterized in that: The talcum powder has a mesh size of 800-1250, a whiteness of ≥98% compared to the standard sample, and a particle size distribution of D 50 =5μm; The silicon powder is 2500 mesh, with a silicon dioxide content of ≥90%; the whiteness is 70-94% of the standard sample; the particle size distribution D 50 =5μm; The precipitated barium sulfate has a mesh size of 1200 and a barium sulfate content of ≥97%; the whiteness is ≥92% compared with the standard sample, and the water-soluble matter content is ≤0.3%.

13. The modified epoxy water-based putty suitable for rail transit vehicles according to claim 4, characterized in that: The aqueous cosolvent is one of dipropylene glycol butyl ether DPNB, propylene glycol methyl ether acetate PMA and diethylene glycol butyl ether DGB, or a mixture of any two or more thereof.

14. A method for preparing a modified epoxy water-based putty suitable for rail transit vehicles, characterized in that: The preparation method of the modified epoxy water-based putty according to any one of claims 1 to 13 comprises the following steps: S1: Preparation of main agent component A The base epoxy resin and the hyperbranched polyester modified epoxy resin are added to a mixing kettle I and mixed evenly; then, the auxiliary agent is added and stirred until the mixture is evenly mixed to obtain a coarse suspension without particles; The obtained coarse suspension is conveyed to a sand mill and ground to a fineness of ≤20µm to obtain a slurry; Then, the mixture is put into a mixing kettle II, and filler A is added under high-speed dispersion at 1000-1200 r / min to disperse the slurry to a fineness of ≤100 μm. The speed is then reduced to 600-800 r / min. Solvent, anti-flash rust agent, and wetting agent are added while stirring, and the mixture is stirred until a uniform paste is formed. The mixture is then ground in a three-roll mill I to a fineness of ≤50 μm, and the proportion of fineness <30 μm is controlled to be 5-10%, the proportion of fineness of 30-35 μm is 60-70%, and the proportion of fineness of 35-50 μm is 20-30%, thereby obtaining component A. Testing, use pure water to adjust the consistency of component A to 13-15; S2: Preparation of curing agent component B Place the modified fatty amine into mixing kettle III, add the additives while stirring, and stir until the mixture is uniform; add filler B at a high-speed dispersion speed of 1000-1200 r / min and disperse to a fineness of ≤100µm; reduce the speed to 600-800 r / min, add the solvent, flash rust inhibitor, and wetting agent while stirring until a uniform paste is formed, and grind it in a three-roll mill II to a fineness of ≤50µm, and control the following: the proportion of fineness <30µm is 5-10%, the proportion of fineness of 30-35µm is 70-80%, and the proportion of fineness of 35-50µm is 15-20%, thereby obtaining component B; Testing, use purified water to adjust the consistency of component B to 12-14; S3: Preparation of modified epoxy water-based putty When using, mix component A and component B according to the weight ratio and stir evenly to obtain modified epoxy water-based putty.

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