Light-cured epoxy resin / polyurethane anticorrosive paint and preparation method thereof

Abstract

The invention discloses a light-cured epoxy resin / polyurethane anticorrosive coating and a preparation method thereof. The preparation method comprises the following steps: preparing light-cured epoxy resin; preparing the light-cured polyurethane; the preparation method comprises the following steps: compounding light-cured epoxy resin, light-cured polyurethane, a diluent and a photoinitiator to obtain the light-cured epoxy resin / polyurethane anticorrosive coating, according to the preparation method disclosed by the invention, two main coating resins, namely epoxy resin and polyurethane, are compounded together to obtain comprehensive performance, polycarbonate polyol is adopted during preparation of polyurethane to strengthen the application performance of the coating, and then a photocuring technology is adopted to realize room-temperature crosslinking of the coating, so that the coating is better in performance, more environment-friendly and more energy-saving.

Description

Technical Field

[0001] The invention relates to the technical field of anti-corrosion coatings, and in particular to a light-cured epoxy resin / polyurethane anti-corrosion coating and a preparation method thereof. Background Art

[0002] Metal corrosion is a process in which the overall performance of a material deteriorates due to chemical changes, electrochemical changes or physical dissolution under the action of corrosive media such as air and water molecules. The isolation method of applying an anti-corrosion coating on the metal surface is the most effective and widely used anti-corrosion measure to date. After the metal is coated with an anti-corrosion coating, it can effectively slow down or prevent the corrosive medium from reaching the metal surface, thereby resisting or weakening the corrosion reaction of the metal and greatly increasing the service life of the metal.

[0003] Epoxy resin is a typical base resin for anti-corrosion coatings. Epoxy resin has the characteristics of high strength, hardness, good adhesion, and excellent chemical resistance. However, the brittleness of epoxy resin is its biggest disadvantage. Polyurethane is also a typical coating resin. Polyurethane has excellent low-temperature resistance, and its high regularity can improve the toughness of the material; the urethane group in the hard segment of the polyurethane molecule has a large steric hindrance in the molecular chain, which can improve the tensile strength and modulus of the material. The cross-linked structure between molecules can improve the mechanical properties of polyurethane materials and give them excellent water resistance and weather resistance. Polyurethane has excellent low-temperature resistance, toughness, impact resistance and wear resistance. Therefore, compounding epoxy resin and polyurethane together can obtain a coating resin with better comprehensive performance.

[0004] Polycarbonate polyol is a polymer with carbonate and alcohol groups in its molecules. It has high thermal stability and oxidation stability, good elasticity and wear resistance, softness and plasticity. It is often used as a raw material for synthesizing polyether carbonate polymer materials and coatings. In some fields, such as automobiles, construction and electronic devices, polycarbonate polyol can also be added to polymers as a plasticizer. However, the polyurethane prepared from polycarbonate polyol as a raw material has too high viscosity and some of it is solid at room temperature. Therefore, the method of adding active diluents can be used to adjust the viscosity of the coating, while introducing a curable double bond structure.

[0005] UV curing is an environmentally friendly and energy-saving curing method, known as "green technology". Currently, UV curing technology is gaining more and more attention in the fields of coatings and adhesives.

[0006] Therefore, how to compound various raw materials to obtain a high-performance anti-corrosion coating has attracted more and more attention.

[0007] In view of this, the present invention is proposed. Summary of the invention

[0008] The purpose of the present invention is to provide a photocurable epoxy resin / polyurethane anti-corrosion coating and a preparation method thereof. The preparation method of the present invention compounds two main coating resins, epoxy resin and polyurethane, together to obtain comprehensive performance, and uses polycarbonate polyols when preparing polyurethane to enhance the application performance of the coating. Photocuring technology is then used to achieve room temperature crosslinking of the coating, so that the coating has better performance and is more environmentally friendly and energy-saving.

[0009] In order to achieve the above-mentioned purpose of the present invention, the following technical solutions are particularly adopted:

[0010] The first aspect of the present invention provides a method for preparing a light-curing epoxy resin / polyurethane anticorrosive coating, the preparation method comprising the following steps:

[0011] (a) Preparation of light-cured epoxy resin:

[0012] Esterifying epoxy resin and unsaturated carboxylic acid to obtain light-curing epoxy resin;

[0013] (b) Preparation of photocurable polyurethane:

[0014] The polyol is reacted with a polyisocyanate monomer to obtain an -NCO-terminated polyurethane prepolymer, and then a (meth)acrylate with a hydroxyl group is used to perform a capping reaction to obtain a light-cured polyurethane;

[0015] (c) Compounding the photocurable epoxy resin, the photocurable polyurethane, the diluent and the photoinitiator to obtain the photocurable epoxy resin / polyurethane anticorrosive coating.

[0016] Preferably, in step (a), the epoxy resin is bisphenol A epoxy resin or novolac epoxy resin;

[0017] The unsaturated carboxylic acid is acrylic acid or methacrylic acid;

[0018] The molar ratio of the epoxy group in the epoxy resin to the carboxyl group in the unsaturated carboxylic acid is (0.8-1):1.

[0019] Preferably, in step (b), the polyol is composed of polyether polyol and polycarbonate polyol, and the molar ratio of polycarbonate polyol to polyether polyol is (25-75): (25-75);

[0020] The molecular weight of polyether polyols and polycarbonate polyols is not higher than 2500, such as PCDL-500, PCDL-1000, PCDL-2000, PPG-400, PPG-1000 and PPG-2000;

[0021] The polyether polyol includes polypropylene glycol (PPG); the polycarbonate polyol includes polycarbonate diol (PCDL).

[0022] Preferably, in step (b), the polyisocyanate monomer is selected from at least one of toluene diisocyanate (TDI), para-phenylene diisocyanate (MDI), hexamethylene diisocyanate (HDI), isophorone diisocyanate (IPDI), xylylene diisocyanate (XDI), and tetramethyl-meta-xylylene diisocyanate (TMDI);

[0023] The amounts of polyisocyanate monomer and polyol are determined according to the molar ratio of -NCO to -OH being 1.10 to 2.10.

[0024] Preferably, in step (b), the (meth)acrylate with a hydroxyl group is selected from at least one of hydroxyethyl acrylate, hydroxypropyl acrylate and hydroxyethyl methacrylate;

[0025] The amount of (meth)acrylate having a hydroxyl group added is controlled so that the end-capping rate is 90% to 100%.

[0026] Preferably, in step (c), the diluent is a liquid monomer with multiple unsaturated C=C double bonds;

[0027] The liquid monomers with multiple unsaturated C=C double bonds include trimethylolpropane triacrylate (TMPTA), trimethylolpropane trimethacrylate (TMPTMA), 1,6-hexanediol diacrylate (HDDA), dipropylene glycol diacrylate (DPGDA) and tripropylene glycol diacrylate (TPGDA).

[0028] Preferably, in step (c), the mass ratio of the photocurable epoxy resin to the photocurable polyurethane is (3-7):(3-7).

[0029] Preferably, in step (c), the amount of the diluent added is 10% to 30% of the total mass of the photocurable epoxy resin and the photocurable polyurethane;

[0030] The added amount of the photoinitiator is 1% to 5% of the total mass of the photocurable epoxy resin and the photocurable polyurethane.

[0031] Preferably, in step (c), the photoinitiator is initiator 1173 (2-hydroxy-2-methyl-1-phenyl-1-propanone) or initiator 184 (1-hydroxycyclohexyl phenyl ketone).

[0032] The second aspect of the present invention provides a light-cured epoxy resin / polyurethane anti-corrosion coating prepared by the above preparation method.

[0033] Compared with the prior art, the beneficial effects of the present invention include at least:

[0034] The preparation method of the present invention compounds two main coating resins, epoxy resin and polyurethane, together to obtain comprehensive performance, and adopts polycarbonate polyol when preparing polyurethane to enhance the application performance of the coating, and then adopts light curing technology to achieve room temperature cross-linking of the coating, so that the coating performance is better and more environmentally friendly and energy-saving. Specifically, polycarbonate polyol is a polymer with carbonate and alcohol groups in its molecules, has high thermal stability and oxidation stability, and has good elasticity and wear resistance, softness and plasticity; epoxy resin has high strength and good adhesion, while polyurethane resin has the characteristics of wear resistance, good resilience, low temperature resistance and the like. The present invention combines epoxy resin with polyurethane to give full play to the excellent performance of the two resins. BRIEF DESCRIPTION OF THE DRAWINGS

[0035] In order to more clearly illustrate the specific embodiments of the present invention or the technical solutions in the prior art, the following is a brief introduction to the drawings required for the specific embodiments or the description of the prior art. In all the drawings, similar elements or parts are generally identified by similar reference numerals. In the drawings, the elements or parts are not necessarily drawn according to the actual scale.

[0036] Figure 1 It is the Bode diagram of 301 stainless steel and UVPEU1 in Experimental Example 1 of the present invention;

[0037] Figure 2 It is the Nyquist diagram of 301 stainless steel in Experimental Example 1 of the present invention;

[0038] Figure 3 It is the Nyquist diagram of the UVPEU1 coating in Experimental Example 1 of the present invention;

[0039] Figure 4 It is the Tafel curve of 301 stainless steel and UVPEU1 in Experimental Example 1 of the present invention. DETAILED DESCRIPTION

[0040] The following embodiments of the technical solution of the present invention are described in detail in conjunction with the embodiments. The following embodiments are only used to more clearly illustrate the technical solution of the present invention, and are therefore only used as examples, and cannot be used to limit the protection scope of the present invention.

[0041] It should be noted that, unless otherwise specified, the technical terms or scientific terms used in this application should have the common meanings understood by those skilled in the art to which the present invention belongs.

[0042] Example 1

[0043] This embodiment is a method for preparing a photocurable epoxy resin, which is prepared using phenolic epoxy resin F-44 and acrylic acid as raw materials under the condition that the epoxy group:carboxyl group (molar ratio) = 1. The preparation method includes the following steps:

[0044] 120g of novolac epoxy resin F-44 (epoxy content of about 0.528mol), 38.02g of acrylic acid (carboxyl content of 0.528mol), 2g of triethylamine, 36g of dioxane and 80mg of phenothiazine were weighed into a reactor. The temperature was raised to 80°C, stirred for reaction for 6h, and then triethylamine and dioxane were removed under reduced pressure to obtain a photocurable epoxy resin, which was recorded as UVPER1.

[0045] Example 2

[0046] This embodiment is a method for preparing a photocurable epoxy resin, which is prepared using bisphenol A epoxy resin and methacrylic acid as raw materials under the condition that the epoxy group:carboxyl group (molar ratio) = 0.9. The preparation method comprises the following steps:

[0047] 100g of bisphenol A epoxy resin E-51 (epoxy content of about 0.52mol), 49.7g of methacrylic acid (carboxyl content of 0.578mol), 2g of triethylamine, 20g of dioxane and 75mg of phenothiazine were weighed into a four-necked flask. The temperature was raised to 80°C, stirred for reaction for 6h, and then triethylamine and dioxane were removed under reduced pressure to obtain a photocurable epoxy resin, which was recorded as UVPER2.

[0048] Example 3

[0049] This embodiment is a method for preparing a photocurable epoxy resin, which is prepared using bisphenol A epoxy resin and acrylic acid as raw materials under the condition that the epoxy group:carboxyl group (molar ratio) = 0.8. The preparation method comprises the following steps:

[0050] 100g of bisphenol A epoxy resin E-44 (epoxy content of about 0.44 mol) was weighed and dissolved in 30g of dioxane, and then 39.6g of acrylic acid (carboxyl content of 0.55 mol), 2g of triethylamine and 70mg of phenothiazine were added to a four-necked flask. The temperature was raised to 80°C, stirred and reacted for 6 hours, and then triethylamine and dioxane were removed under reduced pressure to obtain a photocurable epoxy resin, which was recorded as UVPER3.

[0051] Example 4

[0052] This embodiment is a method for preparing a photocurable polyurethane, using IPDI, PCDL-500, PPG-400 and HEA as raw materials, the formula principle is: PCDL-500:PPG-400=75:25 (molar ratio), when IPDI reacts with PCDL-500 / PPG-400, R=2.1 (R value is the molar ratio of -NCO to -OH, the same below), the end-capping rate of HEA to the polyurethane prepolymer is 90.9%, and the preparation method comprises the following steps:

[0053] 70.0g of IPDI (-NCO content 0.63mol) and 56.25g of PCDL-500 (-OH content 0.225mol) and 15g of PPG-400 (-OH content 0.075mol) were added to the reactor, and the temperature was raised to 80°C under stirring. After the reactants were evenly mixed, 71mg of dibutyltin dilaurate (DBTDL) was added as a catalyst (the amount of catalyst was about 0.05% of the total mass of the reactants, the same below), and the temperature was maintained for 1.5h to obtain a -NCO-terminated polyurethane prepolymer. Then the temperature was lowered to 65°C, 34.49g of hydroxyethyl acrylate HEA (-OH content 0.297mol) was added, and the temperature was maintained for 1.5h to obtain a photocurable polyurethane, which was recorded as UVPU1.

[0054] Among them, when the polyol reacts with the isocyanate monomer, the calculation method of the R value is as follows (the subsequent examples are not listed in detail, this example is used as a reference):

[0055]

[0056] Example 5

[0057] This embodiment is a method for preparing a photocurable polyurethane, using TDI, PCDL-1000, PPG-1000 and HEMA as raw materials, the formula principle is: PCDL-1000:PPG-1000=1:1 (molar ratio), R=1.6, the end-capping rate of HEA to the polyurethane prepolymer is 97%, and the preparation method comprises the following steps:

[0058] 31.35g of toluene diisocyanate TDI (-NCO content 0.36mol) and 56.25g of polycarbonate diol PCDL-1000 (-OH content 0.1125mol) and 56.25g of polyether diol PPG-1000 (-OH content 0.1125mol) were added to the reactor, and the temperature was raised to 80°C under stirring. After the reactants were mixed evenly, 75mg of DBTDL catalyst was added, and the temperature was maintained for 1.5h to obtain -NCO-terminated polyurethane prepolymer. Then the temperature was lowered to 65°C, 17.00g of hydroxyethyl methacrylate HEMA (hydroxyl content 0.139mol) was added, and the temperature was maintained for 1.5h to obtain a light-curable polyurethane, which was recorded as UVPU2.

[0059] Example 6

[0060] This embodiment is a method for preparing a photocurable polyurethane, using HDI, PCDL-500, PPG-2000 and HPA as raw materials, the formula principle is: PCDL-500:PPG-2000=70:30 (molar ratio), R=1.1, the end-capping rate of HPA to polyurethane prepolymer is 100%, and the preparation method comprises the following steps:

[0061] 25.90g of hexamethylene diisocyanate HDI (-NCO content 0.308mol), 49g PCDL-500 (-OH content 0.196mol) and 84g PPG-2000 (-OH content 0.84mol) were added to the reactor, and the temperature was raised to 80°C under stirring. After the reactants were evenly mixed, 80mg of DBTDL was added as a catalyst, and the temperature was maintained for 1.5h to obtain a -NCO-terminated polyurethane prepolymer. Then the temperature was lowered to 65°C, 3.65g of hydroxypropyl acrylate HPA (hydroxyl content 0.03mol) was added, and the temperature was maintained for 1.5h to obtain a photocurable polyurethane, which was recorded as UVPU3.

[0062] Example 7

[0063] This embodiment is a method for preparing a photocurable polyurethane, using IPDI, PCDL-1000, PPG-400 and HEA as raw materials, the formula principle is: PCDL-1000:PPG-400=25:75 (molar ratio), R=2.1, the end-capping rate of HEA is 90%, and the preparation method comprises the following steps:

[0064] 70.0g IPDI (-NCO content 0.63mol), 37.5g PCDL-1000 (-OH content 0.075mol) and 45g PPG-400 (-OH content 0.225mol) were added to the reactor, and the temperature was raised to 80°C under stirring. After the reactants were evenly mixed, 77mg catalyst DBTDL was added, and the temperature was maintained for 1.5h to obtain -NCO-terminated polyurethane prepolymer. Then the temperature was lowered to 65°C, 38.65g HPA (-OH content 0.297mol) was added, and the temperature was maintained for 1.5h to obtain a photocurable polyurethane, which was recorded as UVPU4.

[0065] Example 8

[0066] This embodiment is a method for preparing a photocurable polyurethane, using IPDI, PCDL-2000, PPG-400 and HEA as raw materials, the formula principle is: PCDL-2000:PPG-400=40:60, R=1.5, the end-capping rate of HEA is 95%, and the preparation method comprises the following steps:

[0067] Add 50.0g IPDI (-NCO content 0.45mol), 120.0g PCDL-500 (-OH content 0.12mol) and 36.0g PPG-400 (-OH content 0.18mol) to the reactor, heat to 80°C under stirring, add 0.10g catalyst DBTDL after the reactants are evenly mixed, keep the temperature for 1.5h to obtain -NCO-terminated polyurethane prepolymer. Then cool to 65°C, add 16.55g HEA (-OH content 0.1425mol), keep the temperature for 1.5h to obtain a photocurable polyurethane, recorded as UVPU5.

[0068] Example 9

[0069] This embodiment is a method for preparing a light-curing epoxy resin / polyurethane anticorrosive coating, which is prepared with light-curing epoxy resin UVPER1, light-curing polyurethane UVPU1, reactive diluent trimethylolpropane trimethacrylate TMPTMA, and photoinitiator 1173 as raw materials. For the convenience of comparison, it is named UVPEU1. The formula ratio is shown in Table 1. The preparation method comprises the following steps:

[0070] 50g UVPER1, 50g UVPU1 and 20g TMPTMA were added into a beaker and stirred to mix evenly; then 3.6g photoinitiator 1173 was added and stirred thoroughly to obtain a light-cured epoxy resin / polyurethane anticorrosive coating, which was recorded as UVPEU1. The coating was collected in a black opaque sample bottle for later use.

[0071] Embodiment 10 to Embodiment 14

[0072] Using the same method as in Example 9, different types of UVPER, UVPU, reactive diluents and photoinitiators were compounded together to prepare light-cured epoxy resin / polyurethane anti-corrosion coatings (numbered as UVPEU2, UVPEU3, UVPEU4, UVPEU5 and UVPEU6, respectively). The detailed formula can be found in Table 1.

[0073] Table 1 Light-curing epoxy resin / polyurethane anticorrosive coating formula

[0074]

[0075] Formula principles: the base resin composition UVPER+UVPU=100 (parts by mass), wherein UVPER=30-70%, UVPU=70-30%; the mass ratio of the active diluent to UVPER+UVPU is 10-30%; the mass of the photoinitiator is 1.0-5.0% of the total mass of the base resin and the active diluent.

[0076] Experimental Example 1

[0077] In this experimental example, UVPEU1 coating was used to prepare a light-cured coating, and the anti-corrosion performance of the coating was tested.

[0078] Take a 301 stainless steel sample, polish it with sandpaper, then clean it with ethanol and dry it. Apply the composite light-curing coating UVPEU1 in Table 1 evenly on the clean surface of the 301 stainless steel sample with a coating rod, and then place it in a UV curing instrument for 20 seconds to obtain a light-cured coating.

[0079] The 301 steel plate coated with the photocured coating was used as the working electrode, and a three-electrode system was used. The platinum electrode was used as the counter electrode, and the calomel electrode was used as the reference electrode. The impedance test of the coating was carried out using a CHI600E electrochemical workstation. The open circuit potential (OCP) was a constant value, the perturbation voltage was 20mV, and the frequency range was 0.1-105Hz. The electrochemical cell was filled with 65mL of 3.5% NaCl solution. The cell includes three electrode units: a saturated calomel electrode (SCE) and a platinum sheet as the reference electrode and the auxiliary electrode, respectively. The working electrode is the surface of the steel plate, which is isolated by a glass cell.

[0080] By analyzing the arc radius of the Nyquist diagram and the resistance modulus of the lowest frequency of the Bode diagram in the electrochemical impedance spectroscopy test, the corrosion resistance of the coating can be accurately determined. If the corrosion rate is expressed as Vc, the corrosion rate can be calculated by formula (1); the protective efficiency IE of the coating can be calculated by formula (2).

[0081]

[0082] In the formula, the relative atomic mass of A—Fe (55.85 g·mol -1 )

[0083] n—Chemical valence of Fe (n=3)

[0084] Ic—Corrosion current of coating, μA·cm -2

[0085] d—density of stainless steel 301 (7.93 g·cm -3 )

[0086] F—Faraday constant (96500C·mol -1 )

[0087] Ic0—Corrosion current of stainless steel 301, μA·cm -2 .

[0088] The model analysis data of the electrochemical corrosion test of UVPEU1 coating is shown in the attached figure. Figure 1 ~Attached Figure 4The calculated anti-corrosion characteristic parameters are listed in Table 2. The electrochemical test shows that the corrosion rate of 301 stainless steel is 1594μm / a, while after UVPEU1 coating protection, the corrosion rate is reduced to 49.96μm / a. The calculated protection efficiency of UVPEU1 coating for 301 stainless steel reaches 96.86%.

[0089] Experimental Example 2

[0090] The photocurable coatings UVPEU2 to UVPEU6 in Table 1 were respectively used to test the anticorrosion performance of each coating type according to the operating method of Experimental Example 1. The results are summarized in Table 2.

[0091] Table 2 Test results of the anticorrosion effect of each composite coating on 301 stainless steel

[0092]

[0093] It can be seen from Table 2 that when no coating protection is performed, the corrosion rate of 301 stainless steel is 1594.50 μm / a. After coating with light-cured epoxy resin / polyurethane coating, the corrosion rate is greatly reduced. The protection efficiency of each coating sample for 301 stainless steel reaches 96%, showing a good anti-corrosion protection effect.

[0094] Finally, it should be noted that the above embodiments are only used to illustrate the technical solutions of the present invention, rather than to limit it. Although the present invention has been described in detail with reference to the aforementioned embodiments, those skilled in the art should understand that they can still modify the technical solutions described in the aforementioned embodiments, or replace some or all of the technical features therein by equivalents. These modifications or replacements do not make the essence of the corresponding technical solutions deviate from the scope of the technical solutions of the embodiments of the present invention, and they should all be included in the scope of the claims and specification of the present invention.

Claims

1. A method for preparing a light-curing epoxy resin / polyurethane anticorrosive coating, characterized in that: The preparation method comprises the following steps: (a) Preparation of light-cured epoxy resin: Esterifying epoxy resin and unsaturated carboxylic acid to obtain light-curing epoxy resin; (b) Preparation of photocurable polyurethane: The polyol is reacted with a polyisocyanate monomer to obtain an -NCO-terminated polyurethane prepolymer, and then a (meth)acrylate with a hydroxyl group is used for the end-capping reaction to obtain a light-cured polyurethane; (c) Compounding the photocurable epoxy resin, the photocurable polyurethane, the diluent and the photoinitiator to obtain the photocurable epoxy resin / polyurethane anticorrosive coating.

2. The preparation method according to claim 1, characterized in that: In the step (a), the epoxy resin is a bisphenol A epoxy resin or a novolac epoxy resin; The unsaturated carboxylic acid is acrylic acid or methacrylic acid; The molar ratio of the epoxy group in the epoxy resin to the carboxyl group in the unsaturated carboxylic acid is (0.8-1):

1.

3. The preparation method according to claim 1, characterized in that: In the step (b), the polyol is composed of polyether polyol and polycarbonate polyol, and the molar ratio of polycarbonate polyol to polyether polyol is (25-75): (25-75); The molecular weight of polyether polyol and polycarbonate polyol shall not exceed 2500; The polyether polyol includes polypropylene glycol; the polycarbonate polyol includes polycarbonate diol.

4. The preparation method according to claim 1, characterized in that: In the step (b), the polyisocyanate monomer is selected from at least one of toluene diisocyanate, p-phenylene diisocyanate, hexamethylene diisocyanate, isophorone diisocyanate, xylylene diisocyanate and tetramethyl-m-xylylene diisocyanate; The amounts of polyisocyanate monomer and polyol are determined according to the molar ratio of -NCO to -OH being 1.10 to 2.

10.

5. The preparation method according to claim 1, characterized in that: In the step (b), the (meth)acrylate with a hydroxyl group is selected from at least one of hydroxyethyl acrylate, hydroxypropyl acrylate and hydroxyethyl methacrylate; The amount of (meth)acrylate having a hydroxyl group added is controlled so that the end-capping rate is 90% to 100%.

6. The preparation method according to claim 1, characterized in that: In the step (c), the diluent is a liquid monomer with multiple unsaturated C=C double bonds; The liquid monomers with multiple unsaturated C=C double bonds include trimethylolpropane triacrylate, trimethylolpropane trimethacrylate, 1,6-hexanediol diacrylate, dipropylene glycol diacrylate and tripropylene glycol diacrylate.

7. The preparation method according to claim 1, characterized in that: In the step (c), the mass ratio of the photocurable epoxy resin to the photocurable polyurethane is (3-7):(3-7).

8. The preparation method according to claim 1, characterized in that: In the step (c), the amount of the diluent added is 10% to 30% of the total mass of the photocurable epoxy resin and the photocurable polyurethane; The added amount of the photoinitiator is 1% to 5% of the total mass of the photocurable epoxy resin and the photocurable polyurethane.

9. The preparation method according to claim 1, characterized in that: In the step (c), the photoinitiator is initiator 1173 or initiator 184.

10. A light-cured epoxy resin / polyurethane anticorrosive coating prepared according to the preparation method described in any one of claims 1 to 9.

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