A water-based bio-based epoxy emulsion, anti-corrosion coating, and preparation method and application thereof

Abstract

The present invention belongs to the technical field of coatings, and specifically relates to an aqueous bio-based epoxy emulsion, an anti-corrosion coating, and a preparation method and application thereof. The aqueous bio-based epoxy emulsion of the present invention comprises a bio-based epoxy resin, a bisphenol A epoxy resin, a bio-based emulsifier, and a non-bio-based emulsifier; the mass ratio of the bio-based epoxy resin to the bisphenol A epoxy resin is 1 to 6:1. The present invention controls the amount of bio-based epoxy resin and bisphenol A epoxy resin, thereby increasing the content of bio-based raw materials in the emulsion and improving storage stability while ensuring good performance of the emulsion. The anti-corrosion coating prepared using the above-mentioned aqueous bio-based epoxy emulsion has excellent comprehensive performance, overcomes the shortcomings of the mechanical properties and insufficient adhesion of the bio-based epoxy coatings in the prior art, and has excellent mechanical properties, anti-corrosion properties, water resistance and adhesion.

Description

Technical Field

[0001] The invention belongs to the technical field of coatings, and specifically relates to a water-based bio-based epoxy emulsion, an anti-corrosion coating, and a preparation method and application thereof. Background Art

[0002] Epoxy coatings play an important role in the field of anti-corrosion coatings, with a usage of more than 40% and still on an upward trend. The main raw materials of traditional epoxy resins all come from fossil fuels. With the continuous reduction of these non-renewable raw materials, their prices continue to rise, which on the one hand leads to the unsustainability of future development, and on the other hand leads to the continuous increase in manufacturing costs. Therefore, it is necessary to develop some new raw materials to replace traditional fossil fuels. Bio-based epoxy resin has been proven to be a potential raw material to replace traditional epoxy resin, but the performance of bio-based epoxy resin coatings, especially mechanical properties, anti-corrosion properties, water resistance, adhesion, etc., is still somewhat different from that of traditional epoxy resin coatings.

[0003] At present, there are many studies on bio-based epoxy resin coatings. These studies mainly focus on two aspects: one is how to increase the content of bio-based raw materials in coatings, and the other is how to improve the performance of bio-based epoxy resins. However, there are few reports on the preparation of bio-based epoxy coatings with excellent comprehensive performance. The current reported bio-based epoxy coatings are mainly concentrated in the field of solvent-based and solvent-free coatings, and only some performances are excellent, and the comprehensive performance is lacking. Although the relevant technology provides a bio-based epoxy coating with excellent wear resistance and anti-corrosion performance, its adhesion is only level 2 at best, and its impact resistance is only 50cm at best, and no bending resistance data is provided. Therefore, it is difficult to achieve large-scale application in some industrial fields such as engineering machinery and rail transit. In addition, there are very few reports on water-based bio-based epoxy coatings, so how to prepare water-based bio-based epoxy coatings with excellent comprehensive performance is still a major difficulty. Water-based coatings have the advantages of safety, environmental protection and easy construction. Therefore, the preparation of water-based bio-based epoxy anti-corrosion coatings with excellent comprehensive performance, especially for rail transit and engineering machinery with high requirements for mechanical properties, anti-corrosion properties and adhesion, has broad prospects and is also a trend of future development. Summary of the invention

[0004] The present invention aims to solve at least one of the technical problems existing in the above-mentioned prior art. To this end, the present invention proposes a water-based bio-based epoxy emulsion, which is applied to anti-corrosion coatings and can effectively improve the mechanical properties, anti-corrosion properties, water resistance and adhesion of the coatings.

[0005] The present invention also provides a method for preparing the aqueous bio-based epoxy emulsion.

[0006] The present invention further provides an anti-corrosion coating containing the above-mentioned water-based bio-based epoxy emulsion, and a preparation method and application thereof.

[0007] In a first aspect of the present invention, an aqueous bio-based epoxy emulsion is provided, comprising a bio-based epoxy resin, a bisphenol A epoxy resin, a bio-based emulsifier, and a non-bio-based emulsifier; the mass ratio of the bio-based epoxy resin to the bisphenol A epoxy resin is 1 to 6:1.

[0008] According to the first aspect of the present invention, there are at least the following beneficial effects:

[0009] The present invention controls the amount of bio-based epoxy resin and bisphenol A epoxy resin, while ensuring good performance of the emulsion, increases the content of bio-based raw materials in the emulsion, the particle size of the emulsion is less than 1.0 μm, and the storage stability is good. Pure bio-based emulsifiers have poor effects, and by using them in combination with non-bio-based emulsifiers, the proportion of bio-based raw materials is increased while ensuring the stability of the water-based bio-based epoxy emulsion.

[0010] Preferably, the mass ratio of the bio-based epoxy resin to the bisphenol A epoxy resin is 1 to 5:1, more preferably 1.5 to 4:1, and further preferably about 2.3:1.

[0011] Preferably, the mass ratio of the bio-based emulsifier to the non-bio-based emulsifier is 1 to 4:1, more preferably 1 to 3:1, and further preferably about 2:1.

[0012] Preferably, the average particle size of the aqueous bio-based epoxy emulsion is 0.2 to 1 μm, more preferably 0.5 to 1 μm, and further preferably 0.55 to 0.7 μm.

[0013] Preferably, the epoxy equivalent of the aqueous bio-based epoxy emulsion is 800-1200, more preferably 1000-1100, further preferably about 1050.

[0014] Preferably, the water-based bio-based epoxy emulsion comprises the following components in parts by weight:

[0015] 20-60 parts of bio-based epoxy resin;

[0016] 5-30 parts of bisphenol A epoxy resin;

[0017] 2-15 parts of bio-based emulsifier;

[0018] 1 to 8 parts of non-biobased emulsifier.

[0019] Preferably, the water-based bio-based epoxy emulsion comprises the following components in parts by weight:

[0020] 30-45 parts of bio-based epoxy resin;

[0021] 10-20 parts of bisphenol A epoxy resin;

[0022] 3-10 parts of bio-based emulsifier;

[0023] 1 to 6 parts of non-biobased emulsifier.

[0024] Preferably, the water-based bio-based epoxy emulsion further comprises at least one of an organic solvent and water.

[0025] Preferably, the water-based bio-based epoxy emulsion comprises the following components in parts by weight:

[0026] 30-45 parts of bio-based epoxy resin;

[0027] 10-20 parts of bisphenol A epoxy resin;

[0028] 3-10 parts of bio-based emulsifier;

[0029] 1 to 6 parts of non-biobased emulsifier;

[0030] 3 to 10 parts of organic solvent;

[0031] 30-45 parts of water.

[0032] Preferably, the water-based bio-based epoxy emulsion comprises the following components in parts by weight:

[0033] 30-40 parts of bio-based epoxy resin;

[0034] 10-20 parts of bisphenol A epoxy resin;

[0035] 6-9 parts of bio-based emulsifier;

[0036] 3-6 parts of non-biobased emulsifier;

[0037] 3-5 parts of organic solvent;

[0038] 30-35 parts of water.

[0039] Preferably, the epoxy equivalent of the bio-based epoxy resin is 50-300, more preferably 100-200.

[0040] Preferably, the viscosity of the bio-based epoxy resin is less than 15 Pa·s (25° C.), and more preferably the viscosity is 8 to 15 Pa·s (25° C.).

[0041] Preferably, the bio-based epoxy resin includes at least one of a vegetable oil epoxy resin, a cashew nut shell oil-based epoxy resin, and a lignin-based epoxy resin.

[0042] Preferably, the softening point of the bio-based emulsifier is below 70°C, more preferably below 60°C.

[0043] Preferably, the bisphenol A epoxy resin is a traditional epoxy resin, including at least one of E-20 epoxy resin, E-12 epoxy resin, E-44 epoxy resin, and E-51 epoxy resin.

[0044] Preferably, the molecular weight of the bisphenol A epoxy resin is less than 2000, more preferably less than 1000.

[0045] Preferably, the pH value (1% aqueous solution) of the bio-based emulsifier is 5-8, and more preferably the pH value (1% aqueous solution) is 6-8.

[0046] Preferably, the viscosity of the bio-based emulsifier is less than 1.8 Pa·s (60°C), more preferably less than 1.5 Pa·s (60°C), and further preferably 0.5-1.0 Pa·s (60°C).

[0047] Preferably, the bio-based emulsifier comprises plant polyphenol-modified polyoxyethylene ether.

[0048] Preferably, the non-biobased emulsifier is at least one of NP series emulsifiers and OP series emulsifiers, and more preferably the non-biobased emulsifier includes at least one of NP-15 and OP-10.

[0049] Preferably, the HLB value of the non-bio-based emulsifier is less than 15, and more preferably the HLB value of the non-bio-based emulsifier is less than 10.

[0050] Preferably, the organic solvent is an alcohol ether solvent, including at least one of propylene glycol methyl ether and ethylene glycol propyl ether.

[0051] The second aspect of the present invention provides a method for preparing the aqueous bio-based epoxy emulsion, comprising the following steps: mixing the components of the aqueous bio-based epoxy emulsion to obtain the aqueous bio-based epoxy emulsion.

[0052] Preferably, the method for preparing the water-based bio-based epoxy emulsion comprises the following steps:

[0053] S1, heating and melting a bio-based epoxy resin, a bisphenol A epoxy resin, and a bio-based emulsifier to obtain a mixed solution;

[0054] S2, adding the non-bio-based emulsifier dropwise into the mixed solution, and after the non-bio-based emulsifier is added dropwise, adding water dropwise, and discharging to obtain the aqueous bio-based epoxy emulsion.

[0055] Preferably, in step S1, the heating and melting temperature is 60-100°C, more preferably 70-80°C.

[0056] Preferably, in step S2, stirring is performed during the dropwise addition process; the dropwise addition rate of the non-bio-based emulsifier is 1 to 2 drops per second; the dropwise addition rate of water is 1 to 2 drops per second. The stirring rate during the dropwise addition process is 1500 to 2500 rpm, more preferably about 2000 rpm.

[0057] Preferably, in step S2, the added water is preheated, specifically, the water is preheated to 60-90°C, more preferably the water is preheated to about 80°C.

[0058] Preferably, in step S2, water is added dropwise in two stages. The first stage of water addition is carried out after the non-biobased emulsifier is added dropwise. The water is added dropwise to 1 / 6 to 1 / 3 of the total amount of water and then stopped. The dispersion is maintained at 1500 to 2500 rpm for 30 to 70 minutes. Then, the second stage of water addition is carried out by adding the remaining water dropwise. After the addition is completed, the dispersion is carried out at 800 to 1200 rpm for 20 to 30 minutes.

[0059] Preferably, the first stage of dripping is carried out after the non-biobased emulsifier is dripped, and the dripping is stopped when 1 / 5 to 1 / 4 of the total amount of water is added, and dispersion is maintained at 2000 rpm for 50 minutes, and then the second stage of dripping is carried out, and the remaining water is dripped. After the dripping is completed, dispersion is carried out at 1000 rpm for 25 minutes.

[0060] Preferably, in step S2, filtering is further performed after discharging the material, and the mesh size of the filter is 1000-2000 mesh, more preferably 1250 mesh.

[0061] According to a third aspect of the present invention, an anti-corrosion coating is provided, wherein the anti-corrosion coating comprises the water-based bio-based epoxy emulsion.

[0062] Preferably, the anticorrosive coating comprises component A and component B.

[0063] Component A includes the following components by weight:

[0064] 20-60 parts of water-based bio-based epoxy emulsion;

[0065] Petroleum resin 2.0-8.0 parts;

[0066] 0.1-2 parts of multifunctional additives;

[0067] Component B includes the following components in parts by weight:

[0068] 5-20 parts of water-based amine curing agent.

[0069] Preferably, the anticorrosive coating comprises component A and component B.

[0070] Component A includes the following components by weight:

[0071] 30-50 parts of water-based bio-based epoxy emulsion;

[0072] Petroleum resin 1.0-5.0 parts;

[0073] 0.5-1 part of multifunctional additive;

[0074] Component B includes the following components in parts by weight:

[0075] 5-15 parts of water-based amine curing agent.

[0076] Preferably, the A component comprises the following components in parts by weight:

[0077] 20-60 parts of water-based bio-based epoxy emulsion;

[0078] 1-8 parts of petroleum resin;

[0079] Adhesion promoter 0.5-3 parts;

[0080] 2-20 parts of anti-rust pigment;

[0081] 10-45 parts of pigments and fillers;

[0082] Wetting and dispersing agent 0.1 to 3 parts;

[0083] 0.1-2 parts of multifunctional additives;

[0084] 0.5 to 8 parts of film-forming aid;

[0085] Defoaming agent 0.1-1 part;

[0086] Thickener 0.2-3 parts;

[0087] 0.1-0.5 parts of substrate wetting agent;

[0088] Active diluent 0-10 parts;

[0089] 0-15 parts of water.

[0090] Preferably, the A component comprises the following components in parts by weight:

[0091] 35-50 parts of water-based bio-based epoxy emulsion;

[0092] 3-5 parts of petroleum resin;

[0093] Adhesion promoter 0.5-1 part;

[0094] 5-15 parts of anti-rust pigment;

[0095] 20-30 parts of pigments and fillers;

[0096] Wetting and dispersing agent 0.5-1 part;

[0097] 0.5-1 part of multifunctional additive;

[0098] 1 to 5 parts of film-forming aid;

[0099] Defoaming agent 0.1-0.3 parts;

[0100] Thickener 0.5-1.2 parts;

[0101] 0.1-0.2 parts of substrate wetting agent;

[0102] 1 to 4 parts of active diluent;

[0103] 5 to 8 parts of water.

[0104] Preferably, the B component includes the following components in parts by weight:

[0105] 2-25 parts of water-based amine curing agent;

[0106] Anti-flash rust agent 0-1 part;

[0107] 0-20 parts of water.

[0108] Preferably, the B component includes the following components in parts by weight:

[0109] 5-15 parts of water-based amine curing agent;

[0110] Anti-flash rust agent 0.2-0.3 parts;

[0111] 10-15 parts of water.

[0112] Preferably, the petroleum resin is a hydrocarbon liquid resin, and the number of carbon atoms in the petroleum resin is 5 to 15, more preferably 8 to 12. The petroleum resin can effectively improve the mechanical properties and anti-corrosion properties of the coating.

[0113] Preferably, the viscosity of the petroleum resin is 100 to 1000 mPa·s, more preferably 300 to 400 mPa·s.

[0114] Preferably, the petroleum resin has a hydroxyl content of 1.0 to 10.0%, more preferably 1.0 to 5.0%, and further preferably 1.7 to 2.2%.

[0115] Preferably, the adhesion promoter is a silane coupling agent containing epoxy or amino groups, including at least one of γ-glycidyloxypropyltrimethoxysilane, γ-glycidyloxypropyltriethoxysilane, γ-aminopropyltrimethoxysilane, and anilinepropyltrimethoxysilane. The adhesion promoter can not only improve the adhesion of the coating, but also further improve the salt spray resistance of the coating.

[0116] Preferably, the adhesion promoter comprises Momentive MP-200.

[0117] Preferably, the anti-rust pigment comprises at least one of modified zinc phosphate, molybdenum zinc phosphate, and phosphorus-containing silicate.

[0118] Preferably, the anti-rust pigment comprises Haibo's ZMP.

[0119] Preferably, the pigment filler includes at least one of titanium dioxide, iron oxide, talcum powder, barium sulfate, mica powder and wollastonite.

[0120] Preferably, the pigment and filler include at least one of 1250 mesh titanium dioxide, 1250 mesh red iron oxide, 1000 mesh barium sulfate, and 800 mesh mica powder.

[0121] Preferably, the wetting and dispersing agent is a high molecular polymer containing pigment affinity groups, including at least one of BYK-190 and TEGO755W.

[0122] Preferably, the multifunctional additive is a high molecular polymer containing a hydrophobic group. The multifunctional additive can enhance the functions of salt spray resistance, water resistance and auxiliary defoaming.

[0123] Preferably, the multifunctional additive includes Nanjing CX.

[0124] Preferably, the film-forming aid is an ether alcohol or alcohol ester solvent, including at least one of dipropylene glycol n-propyl ether (DPNP) and alcohol ester-12.

[0125] Preferably, the defoaming agent includes at least one of an organosilicon defoaming agent, a polymer defoaming agent, and a mineral oil defoaming agent.

[0126] Preferably, the defoamer comprises BYK-022.

[0127] Preferably, the thickener is at least one of organic bentonite, polyurethane and fumed silica.

[0128] Preferably, the thickener comprises ceramic 12W.

[0129] Preferably, the substrate wetting agent comprises TEGO-4100.

[0130] Preferably, the reactive diluent is a low molecular weight epoxy resin, including glycidyl ether. The addition of the reactive diluent can improve the mechanical properties of the coating.

[0131] Preferably, the active hydrogen equivalent of the water-based amine curing agent is 50-300, more preferably 200-300, further preferably 250-300.

[0132] Preferably, the amine value of the water-based amine curing agent is 50 to 250 mgKOH / g, more preferably 100 to 200 mgKOH / g, and further preferably 140 to 180 mgKOH / g.

[0133] Preferably, the viscosity of the water-based amine curing agent is 2000-40000 cPs (25° C.), more preferably 5500-20000 cPs (25° C.).

[0134] Preferably, the solid content of the water-based amine curing agent is ≥30%, more preferably ≥40%, and further preferably 48-52%.

[0135] Preferably, the waterborne amine curing agent comprises a bio-based cardanol-modified amine.

[0136] Preferably, the flash rust inhibitor comprises Ascordi H-14.

[0137] The fourth aspect of the present invention provides a method for preparing the anti-corrosion coating, comprising the following steps: mixing the components of component A to obtain component A; mixing the components of component B to obtain component B.

[0138] Preferably, the components of component A are mixed to obtain component A, specifically:

[0139] S1, pre-dispersion: mixing deionized water, a wetting dispersant, and a portion of a defoaming agent to obtain a mixture;

[0140] S2, slurry preparation: dispersing the mixed material with pigments, fillers and anti-rust fillers to obtain slurry;

[0141] S3, paint mixing: mixing the slurry with a water-based bio-based epoxy emulsion, and then mixing with a reactive diluent, a petroleum resin, a multifunctional additive, an adhesion promoter, a film-forming additive, and the remaining defoaming agent to obtain a mixed paint;

[0142] S4, thickening: mixing the mixed paint with a thickener and a substrate wetting agent to obtain the A component.

[0143] Preferably, the mass ratio of the defoaming agent added in step S1 to that in step S3 is 1:1-4, more preferably about 1:2.

[0144] Preferably, the stirring rate of step S1 is 200 to 1500 r / min, more preferably 600 to 1000 r / min; and the stirring time is 5 to 10 min.

[0145] Preferably, the stirring rate of step S2 is 1000-3000 r / min, more preferably 1500-2500 r / min; the stirring time is 10-40 min, more preferably 20-30 min.

[0146] Preferably, the fineness of the slurry in step S2 is ≤60 μm, more preferably ≤50 μm.

[0147] Preferably, the stirring rates of step S3 and step S4 are independently 300 to 1500 r / min, more preferably 600 to 1000 r / min; the stirring time is independently 5 to 30 min, more preferably 20 to 30 min.

[0148] Preferably, the components of component B are mixed to obtain component B, specifically, a water-based amine curing agent, water and a flash rust preventer are mixed and filtered to obtain component B.

[0149] Preferably, the stirring rate of the mixing of the components of the B component is 600 to 1000 r / min; and the stirring time is 10 to 15 min.

[0150] Preferably, the mesh size of the filtration is 100 to 500 meshes, more preferably 200 to 300 meshes.

[0151] A fifth aspect of the present invention is the application of the anti-corrosion coating in rail transit and mechanical equipment protection.

[0152] Preferably, the application method is: coating the anti-corrosion coating on the surface of rail transit and mechanical equipment, and curing to obtain an anti-corrosion coating.

[0153] Compared with the prior art, the present invention has at least the following beneficial effects:

[0154] Water-based bio-based epoxy emulsion realizes the water-based nature of bio-based epoxy resin and has good stability. The anti-corrosion coating prepared has excellent comprehensive performance, overcoming the shortcomings of bio-based epoxy coatings obtained in the prior art in terms of mechanical properties, adhesion and other properties. It has excellent mechanical properties, anti-corrosion properties, water resistance, and excellent adhesion on different substrates, and can be widely used in rail transit, mechanical equipment and other fields. DETAILED DESCRIPTION

[0155] The following will be combined with the embodiments to clearly and completely describe the concept of the present invention and the technical effects produced, so as to fully understand the purpose, characteristics and effects of the present invention. Obviously, the described embodiments are only part of the embodiments of the present invention, not all of them. Based on the embodiments of the present invention, other embodiments obtained by those skilled in the art without creative work are all within the scope of protection of the present invention.

[0156] Unless otherwise specified, the raw materials used in the specific embodiments of the present invention are commonly used raw materials in the art, and the test / test methods are conventional methods in the art.

[0157] Example 1

[0158] In this example, a series of water-based bio-based epoxy emulsions A to D were prepared. The raw materials were as shown in Table 1. The specific process was as follows:

[0159] 1. Place bio-based epoxy resin, bisphenol A epoxy resin and bio-based emulsifier in a clean empty kettle, heat to 80°C until completely melted, and then mechanically disperse and mix them evenly after they are completely melted.

[0160] 2. After the bio-based epoxy resin, bisphenol A epoxy resin and bio-based emulsifier are evenly dispersed, slowly add the non-bio-based emulsifier while stirring (the dropping rate is 1 drop per second). After the addition is completed, add deionized water (deionized water is preheated to 80°C) at a dropping rate of 2 drops per second.

[0161] 3. Stop adding drops when the mixture turns milky white (the amount of water added accounts for 20% to 25% of the total amount of water added), and maintain dispersion at 2000 rpm for 50 minutes.

[0162] 4. Continue to add the remaining deionized water. After the addition is completed, disperse it at 1000 rpm for another 25 minutes. Discharge the material and filter it through a 200-mesh filter to obtain the water-based bio-based epoxy emulsion.

[0163] Table 1 Raw materials used in preparing epoxy emulsions in Example 1 and Comparative Examples 1 to 4 (parts by mass)

[0164]

[0165] Embodiments 2 to 6

[0166] The components and materials used in preparing the anticorrosive coatings of Examples 2 to 6 are shown in Table 2, and the specific process is as follows:

[0167] 1. Preparation of component A:

[0168] (1) Pre-dispersion: Stir deionized water, wetting dispersant, and one-third defoamer to disperse uniformly at a stirring rate of 800 r / min and a stirring time of 5 min;

[0169] (2) Slurry preparation: Add pigments and anti-rust pigments to the mixture obtained in (1), and disperse at a high speed of 2500 r / min until the fineness is less than or equal to 50 μm to obtain slurry;

[0170] (3) Paint mixing: add bio-based epoxy resin to the slurry, stir and disperse evenly, then add active diluent, petroleum resin, multifunctional additive, adhesion promoter, film-forming additive, and remaining defoamer in sequence, disperse evenly, stir at a speed of 1000 r / min, and stir for 20 min;

[0171] (4) Thickening: Add thickener and base material wetting agent and stir at 800 r / min for 30 min to mix evenly. Filter through 200 mesh to obtain component A.

[0172] 2. Preparation of component B:

[0173] The water-based amine curing agent, deionized water and anti-flash rust agent were dispersed at 600 r / min for 15 minutes, mixed evenly, and filtered through 200 meshes to obtain component B.

[0174] Table 2 Amount of each component of the anticorrosive coating of Examples 2 to 6 and Comparative Examples 5 to 8 (parts by mass)

[0175]

[0176]

[0177] Unless otherwise specified, the specific raw materials used in Examples 2 to 6 are as follows:

[0178] Anti-rust pigment: Haibo's ZMP;

[0179] Pigments and fillers: 1250 mesh titanium dioxide, 1250 mesh red iron oxide, 1000 mesh barium sulfate, 800 mesh mica powder;

[0180] Wetting and dispersing agent: BYK-190;

[0181] Active diluent: Anhui Xinyuan XY-678;

[0182] Petroleum resin: viscosity is 300-400mPa·s, hydroxyl content is 1.7-2.2%;

[0183] Multifunctional additives: Nanjing Yihua CX;

[0184] Adhesion promoter: Momentive MP-200;

[0185] Film-forming aid: Dow DPNB;

[0186] Defoamer: BYK-022;

[0187] Thickener: Dow 12W;

[0188] Water-based amine curing agent: amine value is 140-180 mgKOH / g, active hydrogen equivalent is 250-300;

[0189] Anti-flash rust agent: Ascodi H-14;

[0190] Substrate wetting agent: TEGO-4100.

[0191] Comparative Example 1

[0192] In this comparative example, an epoxy emulsion E is prepared. The main difference from the bio-based epoxy emulsion C in Example 1 is that it does not contain bisphenol A epoxy resin. The detailed formula is shown in Table 1. The specific process is similar to that in Example 1.

[0193] Comparative Example 2

[0194] In this comparative example, an epoxy emulsion F is prepared. The main difference between the epoxy emulsion F and the bio-based epoxy emulsion C in Example 1 is that the epoxy emulsion F does not contain a bio-based epoxy resin. The detailed formula is shown in Table 1. The specific process is similar to that in Example 1.

[0195] Comparative Example 3

[0196] In this comparative example, an epoxy emulsion G is prepared. The main difference from the bio-based epoxy emulsion C in Example 1 is that the amount of bio-based epoxy resin used is small (the mass ratio of bio-based epoxy resin to bisphenol A epoxy resin is 3:7). The detailed formula is shown in Table 1, and the specific process is similar to that in Example 1.

[0197] Comparative Example 4

[0198] In this comparative example, an epoxy emulsion H is prepared. The main difference from the bio-based epoxy emulsion C in Example 1 is that the amount of bisphenol A epoxy resin used is small (the mass ratio of bio-based epoxy resin to bisphenol A epoxy resin is 9:1). The detailed formula is shown in Table 1, and the specific process is similar to that in Example 1.

[0199] Comparative Example 5

[0200] In this comparative example, an anti-corrosion coating is prepared. The main difference between the anti-corrosion coating in Example 4 and that in Example 4 is that epoxy emulsion E is used to replace the bio-based epoxy emulsion C in Example 4. The detailed formula is shown in Table 2. The specific process is similar to that in Example 4.

[0201] Comparative Example 6

[0202] In this comparative example, an anti-corrosion coating is prepared. The main difference between the anti-corrosion coating in Example 4 and that in Example 4 is that epoxy emulsion F is used to replace the bio-based epoxy emulsion C in Example 4. The detailed formula is shown in Table 2. The specific process is similar to that in Example 4.

[0203] Comparative Example 7

[0204] In this comparative example, an anti-corrosion coating is prepared. The main difference between the anti-corrosion coating in Example 4 and that in Example 4 is that epoxy emulsion G is used to replace the bio-based epoxy emulsion C in Example 4. The detailed formula is shown in Table 2. The specific process is similar to that in Example 4.

[0205] Comparative Example 8

[0206] In this comparative example, an anti-corrosion coating is prepared. The main difference between the anti-corrosion coating in Example 4 and that in Example 4 is that epoxy emulsion H is used to replace the bio-based epoxy emulsion C in Example 4. The detailed formula is shown in Table 2. The specific process is similar to that in Example 4.

[0207] Comparative Example 9

[0208] This comparative example is a typical commercially available epoxy primer for rail transit.

[0209] Test example

[0210] 1. Performance test of epoxy emulsion

[0211] Table 3 Properties of epoxy emulsions prepared in Example 1 and Comparative Examples 1 to 4

[0212]

[0213] The average particle size of the water-based bio-based epoxy emulsions A to D prepared in Example 1 of the present invention is between 0.55 and 0.7 μm, the particle size is moderate, the epoxy equivalent is 1050, and it has good storage stability. There is no significant change after storage for 12 months, and it can improve the anti-corrosion performance and mechanical properties of the coating. In Comparative Examples 1 to 4, the bio-based epoxy resin and bisphenol A epoxy resin are used in inappropriate dosage ratios, and the comprehensive performance of the prepared emulsions is poor, indicating that the water-based bio-based epoxy resin and bisphenol A epoxy resin are used in a specific ratio. The ratio has a certain degree of improvement in the particle size, storage stability, and epoxy equivalent of the emulsion, thereby improving the comprehensive performance of the coating.

[0214] 2. Performance test of anti-corrosion coating

[0215] According to the raw material dosage in Table 2, component A and component B were mixed, and various properties of the paint film were tested after curing. The cupping test was tested according to GB / T-9753-2007, and other properties were tested according to the relevant requirements of the paint film in HG / T 4759-2014. The substrates used for the adhesion test were carbon steel and magnesium-aluminum alloy.

[0216] Table 4 Various properties of the paint films of Examples 2 to 6 of the present invention and Comparative Examples 5 to 9

[0217]

[0218]

[0219] As can be seen from Table 4, the bio-based epoxy anti-corrosion coatings prepared in Examples 2 to 6 of the present invention have excellent mechanical properties, adhesion, anti-corrosion properties and good storage stability. Comparative Examples 5 to 8 use epoxy emulsions with inappropriate average particle size, poor storage stability, or small epoxy equivalent to prepare coatings, and the coating film appearance, curing properties, mechanical properties, storage stability, etc. are significantly deteriorated. Compared with the commercially available rail transit epoxy primer in Comparative Example 9, the bio-based epoxy anti-corrosion coating of the present invention has a shorter drying time; better mechanical properties, especially impact resistance; and relatively better adhesion to the substrate, salt spray resistance, and storage stability.

[0220] The above is a detailed description of the embodiments of the present invention, but the present invention is not limited to the above embodiments. Various changes can be made within the knowledge of ordinary technicians in the relevant technical field without departing from the purpose of the present invention. In addition, the embodiments of the present invention and the features in the embodiments can be combined with each other without conflict.

Claims

1. A water-based bio-based epoxy emulsion, characterized in that: It includes bio-based epoxy resin, bisphenol A epoxy resin, bio-based emulsifier, and non-bio-based emulsifier; the mass ratio of the bio-based epoxy resin to the bisphenol A epoxy resin is 1 to 6:1; The water-based bio-based epoxy emulsion comprises the following components in parts by weight: 20-60 parts of bio-based epoxy resin; 5-30 parts of bisphenol A epoxy resin; 2-15 parts of bio-based emulsifier; 1 to 8 parts of non-biobased emulsifier; The mass ratio of the bio-based emulsifier to the non-bio-based emulsifier is 1 to 4:

1.

2. The aqueous bio-based epoxy emulsion according to claim 1, characterized in that The bio-based epoxy resin includes at least one of a plant oil epoxy resin, a cashew nut shell oil-based epoxy resin, and a lignin-based epoxy resin.

3. The aqueous bio-based epoxy emulsion according to claim 1, characterized in that The bio-based emulsifier includes plant polyphenol-modified polyoxyethylene ether.

4. The method for preparing the aqueous bio-based epoxy emulsion according to any one of claims 1 to 3, characterized in that: The method comprises the following steps: mixing various components of the water-based bio-based epoxy emulsion to obtain the water-based bio-based epoxy emulsion.

5. An anti-corrosion coating, characterized in that: The anti-corrosion coating comprises the water-based bio-based epoxy emulsion according to any one of claims 1 to 3.

6. The anticorrosive coating according to claim 5, characterized in that: The anticorrosive coating comprises component A and component B. Component A includes the following components by weight: 20-60 parts of water-based bio-based epoxy emulsion; Petroleum resin 2.0-8.0 parts; Multifunctional additive 0.1-2 parts; Component B includes the following components in parts by weight: 5-20 parts of water-based amine curing agent.

7. The anticorrosive coating according to claim 6, characterized in that: The A component includes the following components in parts by weight: 20-60 parts of water-based bio-based epoxy emulsion; 1-8 parts of petroleum resin; Adhesion promoter 0.5-3 parts; 2-20 parts of anti-rust pigment; 10-45 parts of pigments and fillers; Wetting and dispersing agent 0.1 to 3 parts; 0.1-2 parts of multifunctional additives; 0.5 to 8 parts of film-forming aid; Defoaming agent 0.1-1 part; Thickener 0.2-3 parts; 0.1-0.5 parts of substrate wetting agent; Active diluent 0-10 parts; 0-15 parts of water.

8. The method for preparing the anticorrosive coating according to any one of claims 5 to 7, characterized in that: The method comprises the following steps: mixing the components of component A to obtain component A; and mixing the components of component B to obtain component B.

9. Application of the anti-corrosion coating according to any one of claims 5 to 7 in rail transportation and mechanical equipment protection.

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