Solvent-free hybrid polyurethane activated zinc-rich primer as well as preparation method and application thereof

Abstract

The invention discloses a solvent-free hybrid polyurethane activated zinc-rich primer and a preparation method and application thereof, and belongs to the field of anticorrosive paints.The solvent-free hybrid polyurethane activated zinc-rich primer is obtained by reacting polyisocyanate with an epoxy oligomer in the presence of a composite catalyst, zinc powder and carbon nanotubes are added, and the solvent-free hybrid polyurethane activated zinc-rich primer is obtained. The coating integrates the advantages of an epoxy-polyurethane composite material, has excellent adhesive force, mechanical strength, corrosion resistance and weather resistance, can provide excellent cathode protection, is good in constructability, free of VOC emission, environmentally friendly, safe, non-toxic and odorless, can be sprayed, brushed or roller-coated on the surface of steel and iron, adopts a single-layer or double-layer system, saves labor and time, and can be applied to the surface of the steel and iron. The corrosion inhibitor is suitable for high-corrosion environments including the fields of petrochemical engineering, ocean engineering, infrastructure, energy, mining and smelting, transport vehicles or OEM.

Description

Technical Field

[0001] The present invention relates to the technical field of anti-corrosion coatings, and particularly to a solvent-free hybrid polyurethane activated zinc-rich primer, its preparation method and application. Background Art

[0002] Traditional zinc-rich primers contain a large amount of organic solvents, and these solvents will release volatile organic compounds during use, which are harmful to the environment and human health. With the increasingly strict environmental protection regulations, the development of solvent-free and environmentally friendly zinc-rich primers has become an industry trend. Existing solvent-free coatings usually have high viscosity, short pot life, and difficult construction, and it is difficult to meet the requirements of large-scale applications.

[0003] Zinc-rich primers, including organic and inorganic coatings, are widely used in the fields of ships, ocean engineering, petrochemical industry, infrastructure, energy transportation, etc. Such coatings can be based on various binder systems, such as epoxy, silicate, polysiloxane, polyurethane, cyclized rubber, phenoxy resin, epoxy ester, etc.

[0004] In zinc-rich primers, zinc is used as a conductive pigment to produce an anodic active coating. Zinc, as a sacrificial anode material, protects the steel substrate and makes it the cathode. The anti-corrosion property depends on the transfer of current in the zinc-rich primer. As long as the conductivity in the system is protected and there is enough zinc as the anode, the steel will be cathodically protected. Therefore, the zinc particles in the zinc-rich primer should be closely packed together, and the zinc content in the zinc-rich primer is usually as high as over 60%.

[0005] However, reducing the zinc content in the anti-corrosion coating, reducing the dry film thickness of the coating and the number of construction layers, and improving the anti-corrosion property of the coating system have always been the goals pursued by the coating industry.

[0006] Therefore, it is necessary to develop a green and high-performance zinc-rich primer suitable for the long-term anti-corrosion of steel structures in harsh corrosive atmospheric environments, including the petrochemical industry, ocean engineering, infrastructure, energy, mining and smelting, transportation vehicles or OEM fields, to extend the service life of industrial facilities, reduce energy consumption and VOC emissions, so as to ensure compliance with strict environmental protection regulations. Summary of the Invention

[0007] Technical Problems to be Solved:

[0008] The object of the present invention is to overcome the technical problems existing in the prior art. Therefore, it is necessary to develop a green high-performance zinc-rich primer, which is suitable for the long-term anti-corrosion of steel structures in harsh corrosive atmospheric environments, including petrochemical, offshore engineering, infrastructure, energy, mining and smelting, transportation vehicles or OEM fields, to extend the service life of industrial facilities, reduce energy consumption and VOC emissions, so as to ensure compliance with strict environmental protection regulations. This application provides a solvent-free hybrid polyurethane activated zinc-rich primer, its preparation method and application. The primer is obtained by reacting a polyisocyanate with an epoxy oligomer in the presence of a composite catalyst, and zinc powder and carbon nanotubes are added. Combining the advantages of epoxy-polyurethane composites, it has excellent adhesion, mechanical strength, corrosion resistance and weather resistance, can provide superior cathodic protection, good workability, zero VOC emissions, is environmentally friendly, safe, non-toxic and odorless, can be spray-coated, brush-coated or roll-coated on the steel surface, in a single-layer or double-layer system, saving labor and time, and is suitable for high-corrosion environments, including petrochemical, offshore engineering, infrastructure, energy, mining and smelting, transportation vehicles or OEM fields.

[0009] Technical solution:

[0010] To achieve the above object, this application is realized through the following technical solutions:

[0011] A solvent-free hybrid polyurethane activated zinc-rich primer, the raw materials of the solvent-free hybrid polyurethane activated zinc-rich primer are proportioned by weight: 18-25 parts of polyisocyanate, 13-15 parts of epoxy oligomer, 0.01-0.5 parts of composite catalyst, 60-66 parts of zinc powder, 0.1-0.5 parts of carbon nanotubes, 1-2 parts of additives; the molar ratio between the polyisocyanate and the epoxy oligomer is 1-3:1.

[0012] Preferably, the molar ratio between the polyisocyanate and the epoxy oligomer in the solvent-free hybrid polyurethane activated zinc-rich primer is 1.4-2.2:1; the solid content of the solvent-free hybrid polyurethane activated zinc-rich primer ≥99%; the viscosity of the solvent-free hybrid polyurethane activated zinc-rich primer is 70-110 KU / 23 °C; the pot life of the solvent-free hybrid polyurethane activated zinc-rich primer is 60-100 minutes / 23 °C.

[0013] Preferably, the polyisocyanate is one or several of aromatic diisocyanates, low molecular weight derivatives of aromatic diisocyanates, aliphatic diisocyanates, aliphatic diisocyanate dimers, aliphatic diisocyanate trimers, low molecular weight derivatives of aliphatic diisocyanates, cycloaliphatic diisocyanates, cycloaliphatic diisocyanate monomers, and low molecular weight derivatives of cycloaliphatic diisocyanates.

[0014] Preferably, the aromatic diisocyanate is a mixture of solvent-free 4,4'-diphenylmethane diisocyanate and high-functional isomers or a derivative of MDI, and the functionality of the high-functional isomers is ≥2.5; the aliphatic diisocyanate or alicyclic diisocyanate is selected from one or more of solvent-free isophorone diisocyanate IPDI, 4,4'-dicyclohexylmethane diisocyanate HMDI, hexamethylene diisocyanate HDI, hexamethylene diisocyanate dimer, hexamethylene diisocyanate trimer, and hexamethylene diisocyanate trimer derivatives.

[0015] Preferably, the epoxy oligomer is a reactive epoxy compound, and the reactive epoxy compound is one or more of bisphenol F epoxy resin, hydrogenated bisphenol A epoxy resin, epoxy reactive diluent, and epoxy silane.

[0016] Preferably, the composite catalyst is one or more of 1-alkylimidazole, ionic liquid, and organometallic compound.

[0017] Preferably, the average particle size of the zinc powder is 2-5 μm; the carbon nanotube is a single-walled carbon nanotube, a hollow long tube with a diameter of 1.6±0.4 nm and a length of 5-20 μm; the auxiliary agent is one or more of a water remover, a rheology modifier, and a leveling agent.

[0018] A preparation method of any one of the above solvent-free hybrid polyurethane activated zinc-rich primers comprises the following steps:

[0019] First step: High-speed disperse the epoxy oligomer, auxiliary agent, zinc powder, and composite catalyst until the fineness is ≤40 μm, and then add the carbon nanotube and stir at a speed of 300-500 r / min for 10-20 min to obtain component A;

[0020] Second step: Stir the polyisocyanate at a speed of 300-500 r / min for 10-20 min to obtain component B;

[0021] Third step: Mix component A and component B at a speed of 500-1000 r / min for 1-3 minutes to prepare the solvent-free hybrid polyurethane activated zinc-rich primer.

[0022] The present application also discloses the application of any one of the above solvent-free hybrid polyurethane activated zinc-rich primers in the long-term anti-corrosion protection of the steel surface in a high-corrosion environment, and the high-corrosion environment is the fields of petrochemical industry, ocean engineering, infrastructure, energy, mining and smelting, transport vehicles, or OEM.

[0023] Principle explanation: Single-walled carbon nanotubes are rolled from extremely thin single-layer graphene sheets, with excellent electrical conductivity, strength, temperature / chemical stability, and flexibility. Due to the high aspect ratio of single-walled carbon nanotubes, when embedded in a material matrix, well-dispersed carbon nanotubes will form a three-dimensional conductive network, which plays a role in transferring electrons in the initial cathodic protection of zinc-rich primers, achieving full utilization of zinc. In the middle and late stages, the shielding effect can extend the channels for corrosive media to enter the substrate, realizing better anti-corrosion performance and durability; adding carbon nanotubes to zinc-rich primers can significantly improve the anti-corrosion performance of the coating and cathodic protection of local damage; by forming a conductive network, enhancing the barrier effect, and improving mechanical properties, carbon nanotubes provide longer-lasting and more reliable corrosion protection for zinc-rich coatings, especially suitable for the protection of steel in high-corrosion environments; using an epoxy oligomer - polyisocyanate system, the zinc-rich primer is realized to be low-viscosity and solvent-free, safe, environmentally friendly, and easy to industrialize.

[0024] Beneficial effects:

[0025] This application provides a solvent-free hybrid polyurethane-activated zinc-rich primer and its preparation method and application, with the following beneficial effects:

[0026] 1. The solvent-free hybrid polyurethane-activated zinc-rich primer of this application combines zinc powder and carbon nanotubes, which can significantly improve the anti-corrosion performance of the coating and cathodic protection of local damage; by forming a conductive network, enhancing the barrier effect, and improving mechanical properties, carbon nanotubes provide longer-lasting and more reliable corrosion protection for zinc-rich coatings, especially suitable for the protection of steel in high-corrosion environments;

[0027] 2. The solvent-free hybrid polyurethane-activated zinc-rich primer of this application uses an epoxy oligomer - polyisocyanate system to achieve low-viscosity and solvent-free of the zinc-rich primer, which is safe, environmentally friendly, and easy to industrialize;

[0028] 3. The solvent-free hybrid polyurethane-activated zinc-rich primer of this application is suitable for the corrosion protection of steel in high-corrosion environments, including petrochemical, offshore engineering, infrastructure, energy, mining and smelting, transportation vehicles, or OEM fields;

[0029] 4. The solvent-free hybrid polyurethane-activated zinc-rich primer of this application is a room-temperature curing system, with a solid content requirement of at least 99%, a viscosity of 70 - 110 KU / 23 °C, and a pot life of 60 - 100 minutes / 23 °C; it is constructed by airless spraying, brushing, or rolling, with a curing temperature of 5 - 60 °C and a relative humidity of 10 - 75%; coating system: the first layer is 50 - 200 microns of solvent-free hybrid polyurethane-activated zinc-rich primer, and the second layer is 50 - 120 microns of solvent-free hybrid polyurethane topcoat;

[0030] 5. According to the requirements of the industry standard HG / T 3668-2020 "Zinc-rich Primer", the salt spray resistance of type II organic zinc-rich primer with 60% zinc content is 200h, and the solvent-free hybrid polyurethane activated zinc-rich primer of the present invention is significantly higher than this index. Detailed Embodiments

[0031] It should be noted that, without conflict, the embodiments in this application and the features in the embodiments can be combined with each other. The present invention will be described in detail below with reference to the embodiments.

[0032] According to a typical embodiment of the present invention, a solvent-free hybrid polyurethane activated zinc-rich primer is provided. The raw materials of the solvent-free hybrid polyurethane activated zinc-rich primer are proportioned by weight: 18-25 parts of polyisocyanate, 13-15 parts of epoxy oligomer, 0.01-0.5 part of composite catalyst, 60-66 parts of zinc powder, 0.1-0.5 part of carbon nanotube, and 1-2 parts of auxiliary agent; wherein the molar ratio between polyisocyanate and epoxy oligomer is 1-3:1.

[0033] In the solvent-free hybrid polyurethane activated zinc-rich primer, the molar ratio between polyisocyanate and epoxy oligomer is 1.4-2.2:1; the solid content of the solvent-free hybrid polyurethane activated zinc-rich primer is ≥99%; the viscosity of the solvent-free hybrid polyurethane activated zinc-rich primer is 70-110 KU / 23°C; the pot life of the solvent-free hybrid polyurethane activated zinc-rich primer is 60-100 minutes / 23°C.

[0034] The polyisocyanate is one or more of aromatic diisocyanate, low-polymer derivative of aromatic diisocyanate, aliphatic diisocyanate, dimer of aliphatic diisocyanate, trimer of aliphatic diisocyanate, low-polymer derivative of aliphatic diisocyanate, alicyclic diisocyanate, monomer of alicyclic diisocyanate, and low-polymer derivative of alicyclic diisocyanate.

[0035] Preferably, the aromatic diisocyanate is a mixture of solvent-free 4,4'-diphenylmethane diisocyanate and high-functional isomers or a derivative of MDI, and the functionality of the high-functional isomers is ≥2.5; the aliphatic diisocyanate or alicyclic diisocyanate is selected from one or more of solvent-free isophorone diisocyanate IPDI, 4,4'-dicyclohexylmethane diisocyanate HMDI, hexamethylene diisocyanate HDI, dimer of hexamethylene diisocyanate, trimer of hexamethylene diisocyanate, and derivative of trimer of hexamethylene diisocyanate.

[0036] The aromatic diisocyanate is one or more of Suprasec 5005 (Huntsman), Desmodur 44V20L (Covestro), Lupranate M20 (BASF), and Wannate PM-200 (Wanhua).

[0037] The aliphatic diisocyanate is one or more of Desmodur 3600 (Covestro), Desmodur 3900 (Covestro), Tolonate HDT-LV2 (Vencorex), Coronate HXLV (Tosoh), Wannate HT-500 (Wanhua), Wannate HT-600 (Wanhua), and Desmodur 3400 (Covestro).

[0038] The alicyclic diisocyanate is one or more of Vestanat IPDI (Evonik), Desmodur I (Covestro), Basonat I (BASF), Wannate IPDI (Wanhua), Vestanat H 12 MDI (Evonik), Desmodur W (Covestro), and Wannate HMDI (Wanhua).

[0039] The epoxy oligomer is a reactive epoxy compound, and the reactive epoxy compound is one or more of bisphenol F epoxy resin, hydrogenated bisphenol A epoxy resin, epoxy reactive diluent, and epoxy silane.

[0040] The bisphenol F epoxy resin is one or more of EPON Resin 862 (Hexion), DER 354 (Dow), Araldite 285 (Huntsman), and NPEF-170 (NanYa).

[0041] The hydrogenated bisphenol A epoxy resin is one or more of Eponex Resin 1510 (Hexion), EP-4080E (Adeka), ST-3000 (Kukdo), Epalloy 5000 (CVC), and XY518 (Anhui Xinyuan Technology).

[0042] The epoxy reactive diluent is one or more of Heloxy Modifier 8 (Hexion), Araldite DY-E (Huntsman), Epodil 748 (Evonik), Erisys GE 8 (CVC), and XY748 (Anhui Xinyuan Technology).

[0043] The epoxy silane is one or more of Dynasylan GLYMO (Evonik), Geniosil GF 80 (Wacker), KH-560 (Nanjing Aocheng Chemical Industry), and SCA-E87M (Nanjing Nengde New Material Technology).

[0044] The composite catalyst is one or more of 1-alkylimidazole, ionic liquid, and organometallic compound.

[0045] The 1-alkylimidazole is 1-ethylimidazole, the ionic liquid is 1-ethyl-3-methylimidazole thiocyanate, and the organometallic compound is dibutyltin dilaurate (Dabco Catalyst T-12, Evonik).

[0046] The zinc powder is Zinc Dust Super Extra (Larvik Pigment).

[0047] The carbon nanotubes are TUBALL single-walled carbon nanotubes (OCSIAL) and / or BC-XG230 (Junjiang Technology).

[0048] The auxiliary agent is one or more of a water remover, a rheology modifier, and a leveling agent.

[0049] The water remover is Sylosiv A4, Grace.

[0050] The rheology modifier is Crayvallac Optima, Arkema.

[0051] The leveling agent is silicone.

[0052] A method for preparing a solvent-free hybrid polyurethane zinc-rich primer comprises the following steps:

[0053] First step: High-speed disperse the epoxy oligomer, the auxiliary agent, the zinc powder, and the composite catalyst to a fineness of ≤ 40 μm, then add the carbon nanotubes and stir at a speed of 300 - 500 r / min for 10 - 20 min to obtain Component A;

[0054] Second step: Stir the polyisocyanate at a speed of 300 - 500 r / min for 10 - 20 min to obtain Component B;

[0055] Third step: Mix Component A and Component B at a speed of 500 - 1000 r / min for 1 - 3 minutes to prepare the solvent-free hybrid polyurethane zinc-rich primer.

[0056] Application of solvent-free hybrid polyurethane activated zinc-rich primer in long-term anti-corrosion protection of steel surface in high-corrosion environments, where the high-corrosion environments are petrochemical, offshore engineering, infrastructure, energy, mining and smelting, transportation vehicles or OEM fields.

[0057] The solvent-free hybrid polyurethane activated zinc-rich primer can be applied by well-known construction methods, such as spraying, brushing or roll coating. The curing temperature is 5 - 60 °C and the relative humidity is 10 - 75%.

[0058] A typical coating system for corrosion protection of steel structures in atmospheric corrosion environments is as follows:

[0059] First coat: Solvent-free hybrid polyurethane activated zinc-rich primer, 50 - 200 microns;

[0060] Second coat: Solvent-free hybrid polyurethane weather-resistant topcoat, 50 - 120 microns.

[0061] Example 1:

[0062] A preparation method of a solvent-free hybrid polyurethane activated zinc-rich primer, comprising the following steps:

[0063] First step: Mix 10 parts of bisphenol F epoxy resin (NPEF-170), 4.4 parts of epoxy active diluent (Epodil 748), 0.3 part of epoxy silane (SCA-E87M), 0.04 part of catalyst (1-ethylimidazole), 0.04 part of catalyst (1-ethyl-3-methylimidazole thiocyanate), 0.4 part of rheology modifier (Crayvallac Optima), 0.8 part of water scavenger (Sylosiv A4), and 65.1 parts of zinc powder evenly, disperse at high speed until the fineness ≤ 40 μm, then add 0.22 part of carbon nanotubes and stir at 300 - 500 r / min for 10 - 20 min to obtain Component A;

[0064] Second step: Stir 18.7 parts of aromatic diisocyanate (Wannate PM-200) at 300 - 500 r / min for 10 - 20 min to obtain Component B;

[0065] Third step: Mix Component A and Component B at 500 - 1000 r / min for 1 - 3 minutes to prepare the solvent-free hybrid polyurethane activated zinc-rich primer.

[0066] Example 2:

[0067] A preparation method of a solvent-free hybrid polyurethane activated zinc-rich primer, comprising the following steps:

[0068] Step 1: Mix 9.6 parts of bisphenol F epoxy resin (NPEF-170), 4.2 parts of epoxy active diluent (Epodil748), 0.3 part of epoxy silane (SCA-E87M), 0.04 part of catalyst (1-ethylimidazole), 0.04 part of catalyst (1-ethyl-3-methylimidazole thiocyanate), 0.4 part of rheology modifier (Crayvallac Optima), 0.8 part of water scavenger (SylosivA4), and 62.5 parts of zinc powder evenly, disperse at high speed until the fineness is ≤ 40 μm, then add 0.22 part of carbon nanotubes and stir at a speed of 300 - 500 r / min for 10 - 20 min to obtain Component A;

[0069] Step 2: Stir 21.9 parts of aromatic diisocyanate (Wannate PM-200) at a speed of 300 - 500 r / min for 10 - 20 min to obtain Component B;

[0070] Step 3: Mix Component A and Component B at a speed of 500 - 1000 r / min for 1 - 3 minutes to prepare a solvent-free hybrid polyurethane activated zinc-rich primer.

[0071] Example 3:

[0072] A preparation method of a solvent-free hybrid polyurethane activated zinc-rich primer, comprising the following steps:

[0073] Step 1: Mix 9.2 parts of bisphenol F epoxy resin (NPEF-170), 4.0 parts of epoxy active diluent (Epodil748), 0.3 part of epoxy silane (SCA-E87M), 0.04 part of catalyst (1-ethylimidazole), 0.04 part of catalyst (1-ethyl-3-methylimidazole thiocyanate), 0.4 part of rheology modifier (Crayvallac Optima), 0.8 part of water scavenger (SylosivA4), and 60.2 parts of zinc powder evenly, disperse at high speed until the fineness is ≤ 40 μm, then add 0.22 part of carbon nanotubes and stir at a speed of 300 - 500 r / min for 10 - 20 min to obtain Component A;

[0074] Step 2: Stir 24.8 parts of aromatic diisocyanate (Wannate PM-200) at a speed of 300 - 500 r / min for 10 - 20 min,

[0075] to obtain Component B;

[0076] Step 3: Mix Component A and Component B at a speed of 500 - 1000 r / min for 1 - 3 minutes to prepare a solvent-free hybrid polyurethane activated zinc-rich primer.

[0077] Example 4:

[0078] A preparation method of a solvent-free hybrid polyurethane activated zinc-rich primer, comprising the following steps:

[0079] First step: Mix 9.6 parts of bisphenol F epoxy resin (NPEF-170), 4.2 parts of epoxy active diluent (Epodil748), 0.3 part of epoxy silane (SCA-E87M), 0.04 part of catalyst (1-ethylimidazole), 0.04 part of catalyst (1-ethyl-3-methylimidazole thiocyanate), 0.02 part of catalyst (Dabco Catalyst T-12), 0.4 part of rheological agent (CrayvallacOptima), 0.8 part of water remover (SylosivA4), and 62.5 parts of zinc powder evenly, disperse at high speed until the fineness is ≤ 40μm, then add 0.20 part of carbon nanotubes and stir at a speed of 300-500 r / min for 10-20 min to obtain Component A;

[0080] Second step: Stir 10.95 parts of aliphatic diisocyanate (Wannate HT-600) and 10.95 parts of alicyclic diisocyanate (Wannate IPDI) at a speed of 300-500 r / min for 10-20 min to obtain Component B;

[0081] Third step: Mix Component A and Component B at a speed of 500-1000 r / min for 1-3 minutes to prepare a solvent-free hybrid polyurethane activated zinc-rich primer.

[0082] Example 5:

[0083] A preparation method of a solvent-free hybrid polyurethane activated zinc-rich primer, comprising the following steps:

[0084] First step: Mix 4.8 parts of bisphenol F epoxy resin (NPEF-170), 4.8 parts of hydrogenated bisphenol A epoxy resin (NPEF-170),

[0085] 4.2 parts of epoxy active diluent (Epodil 748), 0.3 part of epoxy silane (SCA-E87M), 0.04 part of catalyst (1-ethylimidazole), 0.04 part of catalyst (1-ethyl-3-methylimidazole thiocyanate), 0.02 part of catalyst (DabcoCatalyst T-12), 0.4 part of rheological agent (Crayvallac Optima), 0.8 part of water remover (SylosivA4), and 62.5 parts of zinc powder evenly, disperse at high speed until the fineness is ≤ 40μm, then add 0.20 part of carbon nanotubes and stir at a speed of 300-500 r / min for 10-20 min to obtain Component A;

[0086] Step 2: Stir 10.95 parts of aliphatic diisocyanate (Wannate HT-600) and 10.95 parts of alicyclic diisocyanate (Wannate IPDI) at a speed of 300 - 500 r / min for 10 - 20 min to obtain Component B;

[0087] Step 3: Mix Component A and Component B at a speed of 500 - 1000 r / min for 1 - 3 minutes to prepare a solvent-free hybrid polyurethane activated zinc-rich primer.

[0088] The compositions and properties of the solvent-free hybrid polyurethane activated zinc-rich primers provided in Examples 1 to 5 are shown in Table 1.

[0089] Table 1: Compositions and film properties of the solvent-free hybrid polyurethane activated zinc-rich primer

[0090]

[0091] The above are only the preferred embodiments of the present invention and are not intended to limit the present invention. For those skilled in the art, various modifications and changes can be made to the present invention. Any modification, equivalent replacement, improvement, etc. made within the spirit and principle of the present invention shall be included within the protection scope of the present invention.

Claims

1. A solvent-free hybrid polyurethane activated zinc-rich primer, characterized in that: The raw materials of the solvent-free hybrid polyurethane activated zinc-rich primer are calculated by weight: 18 to 25 parts of polyisocyanate, 13 to 15 parts of epoxy oligomer, 0.01 to 0.5 parts of composite catalyst, 60 to 66 parts of zinc powder, 0.1 to 0.5 parts of carbon nanotubes, and 1 to 2 parts of additives; in The molar ratio between the polyisocyanate and the epoxy oligomer is 1-3:

1.

2. A solvent-free hybrid polyurethane activated zinc-rich primer according to claim 1, characterized in that: The molar ratio of polyisocyanate to epoxy oligomer in the solvent-free hybrid polyurethane activated zinc-rich primer is 1.4-2.2:1; the solid content of the solvent-free hybrid polyurethane activated zinc-rich primer is ≥99%; the viscosity of the solvent-free hybrid polyurethane activated zinc-rich primer is 70-110 KU / 23°C; and the application period of the solvent-free hybrid polyurethane activated zinc-rich primer is 60-100 minutes / 23°C.

3. A solvent-free hybrid polyurethane activated zinc-rich primer according to claim 1, characterized in that: The polyisocyanate is one or more of aromatic diisocyanates, oligomeric derivatives of aromatic diisocyanates, aliphatic diisocyanates, aliphatic diisocyanate dimers, aliphatic diisocyanate trimers, aliphatic diisocyanate oligomeric derivatives, alicyclic diisocyanates, alicyclic diisocyanate monomers, and alicyclic diisocyanate oligomeric derivatives.

4. A solvent-free hybrid polyurethane activated zinc-rich primer according to claim 3, characterized in that: The aromatic diisocyanate is a mixture of solvent-free 4,4'-diphenylmethane diisocyanate and a high-functionality isomer or a derivative of MDI, and the functionality of the high-functionality isomer is ≥2.5; the aliphatic diisocyanate or alicyclic diisocyanate is selected from one or more of solvent-free isophorone diisocyanate IPDI, 4,4'-dicyclohexylmethane diisocyanate HMDI, hexamethylene diisocyanate HDI, hexamethylene diisocyanate dimer, hexamethylene diisocyanate trimer, and hexamethylene diisocyanate trimer derivatives.

5. A solvent-free hybrid polyurethane activated zinc-rich primer according to claim 1, characterized in that: The epoxy oligomer is an active epoxy compound, and the active epoxy compound is one or more of bisphenol F epoxy resin, hydrogenated bisphenol A epoxy resin, epoxy active diluent, and epoxy silane.

6. The solvent-free hybrid polyurethane activated zinc-rich primer according to claim 1, characterized in that: The composite catalyst is one or more of 1-alkylimidazole, ionic liquid and organic metal compound.

7. The solvent-free hybrid polyurethane activated zinc-rich primer according to claim 1, characterized in that: The average particle size of the zinc powder is 2 to 5 microns; the carbon nanotubes are single-walled carbon nanotubes, which are hollow long tubes with a diameter of 1.6±0.4nm and a length of 5-20μm; and the additives are one or more of a dewatering agent, a rheological agent, and a leveling agent.

8. A method for preparing the solvent-free hybrid polyurethane activated zinc-rich primer according to any one of claims 1 to 7, characterized in that: The following steps are involved: Step 1: Disperse the epoxy oligomer, additive, zinc powder and composite catalyst at high speed to a fineness of ≤40 μm, then add carbon nanotubes and stir at a speed of 300-500 r / min for 10-20 min to obtain component A; Step 2: Stir the polyisocyanate at a speed of 300-500 r / min for 10-20 min to obtain component B; Step 3: Mix component A and component B at a speed of 500-1000 r / min for 1-3 minutes to prepare a solvent-free hybrid polyurethane activated zinc-rich primer.

9. Use of the solvent-free hybrid polyurethane activated zinc-rich primer according to any one of claims 1 to 7 for long-term corrosion protection of steel surfaces in a highly corrosive environment, characterized in that: Highly corrosive environments include petrochemical, marine engineering, infrastructure, energy, mining and smelting, transportation vehicles or OEM fields.

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