CN115260890A

CN115260890A - Silane modified epoxy waterborne polyurethane steel structure anticorrosive paint

Info

Publication number: CN115260890A
Application number: CN202210995737.6A
Authority: CN
Inventors: 张滨
Original assignee: Individual
Current assignee: Individual
Priority date: 2022-08-19
Filing date: 2022-08-19
Publication date: 2022-11-01

Abstract

The invention discloses a silane modified epoxy waterborne polyurethane steel structure anticorrosive paint, and belongs to the technical field of anticorrosive paints. The technical scheme is as follows: the adhesive comprises a component A and a component B, wherein the component A comprises a 100% solid content water-based isocyanate curing agent; the component B comprises organic silicon modified epoxy resin, a composite emulsifier, an antirust pigment, a flatting agent, a salt-fog resistant auxiliary agent, a catalyst and a diluent; the organic silicon modified epoxy resin accounts for 65-85% of the total mass of the component B, the composite emulsifier accounts for 1-3% of the total mass of the component B, the antirust pigment accounts for 5-20% of the total mass of the component B, the flatting agent accounts for 0.1-0.2% of the total mass of the component B, the salt mist resistant additive accounts for 2-6% of the total mass of the component B, and the catalyst accounts for 0.1-0.2% of the total mass of the component B. The anticorrosive paint disclosed by the invention has the advantages of no solvent, water-based environmental protection, no baking, excellent anticorrosive performance and the like, can replace epoxy zinc-rich primer, and can be used for various metal anticorrosive occasions.

Description

Silane modified epoxy waterborne polyurethane steel structure anticorrosive paint

Technical Field

The invention relates to the technical field of anticorrosive coatings, and particularly relates to a silane modified epoxy waterborne polyurethane steel structure anticorrosive coating.

Background

No matter wind power tower barrels, building steel structures or bridges and the like, the traditional anticorrosion scheme is to prime with a solvent type epoxy zinc-rich primer, then coat a solvent type epoxy micaceous iron intermediate paint, finally coat weather-resistant polyurethane or fluorocarbon finish on the surface, and coat fireproof paint on the surface of indoor building steel structures after the intermediate paint is finished. However, this method of preservation has the following problems: the existence of the solvent in the coating can pollute the environment and influence the human health, and the cost of post-treatment is relatively high. Under the environment-friendly development situation of energy conservation and emission reduction, in order to solve the problem of environmental pollution of solvent-based materials, researchers increase a lot of work, and hope to change the solvent-based anticorrosive materials into environment-friendly water-based anticorrosive materials or solvent-free anticorrosive coatings, although the water-based anticorrosive coatings achieve a certain performance, the anticorrosive effect of the water-based anticorrosive coatings is not ideal or comparable to that of solvent-based zinc-rich primers. Secondly, in the existing anticorrosion scheme, the number of coating construction channels of the anticorrosion paint is large, 2-3 channels of epoxy zinc-rich primer are common, 2 channels of epoxy micaceous iron intermediate paint are used, and heating treatment is needed when the temperature is low, so that a space for re-optimization is provided in both the construction efficiency and the energy consumption.

Therefore, an anticorrosive coating is needed to replace the product, which can solve the problem of environmental protection, has high anticorrosive performance, and reduces the construction number and the comprehensive cost.

Disclosure of Invention

The technical problem to be solved by the invention is as follows: the silane modified epoxy waterborne polyurethane steel structure anticorrosive paint has the advantages of no solvent, water-based environmental protection, baking-free property, excellent anticorrosive property and the like, can replace epoxy zinc-rich primer, and can be used in various metal anticorrosive occasions.

The technical scheme of the invention is as follows:

the silane modified epoxy waterborne polyurethane steel structure anticorrosive paint comprises a component A and a component B, wherein the mass ratio of the component A to the component B is 1: (1.5-2.0); wherein the component A comprises a 100 percent solid content aqueous isocyanate curing agent; the component B comprises organic silicon modified epoxy resin, a composite emulsifier, an antirust pigment, a flatting agent, a salt-fog resistant auxiliary agent, a catalyst and a diluent; the organic silicon modified epoxy resin accounts for 65-85% of the total mass of the component B, the composite emulsifier accounts for 1-3% of the total mass of the component B, the antirust pigment accounts for 5-20% of the total mass of the component B, the flatting agent accounts for 0.1-0.2% of the total mass of the component B, the salt spray resistant auxiliary agent accounts for 2-6% of the total mass of the component B, the catalyst accounts for 0.1-0.2% of the total mass of the component B, and the diluent accounts for 5-10% of the total mass of the component B.

Preferably, the waterborne isocyanate curing agent adopts a curing agent with NCO content of more than 20wt% and viscosity of less than 3000 cps; preferably, the aqueous isocyanate curing agent adopts an HDI curing agent, an IPDI curing agent or an MDI curing agent. Such as Bayhydur XP2547 (viscosity 570-730cps, NCO content 22.5 + -0.5), aqueous isocyanate curing agent WD-8200 (100% solids, viscosity 2500 cps) available from Asahi chemical industries, inc., guangdong.

In order to improve the corrosion resistance of the anticorrosive paint and improve the binding force with a base material, epoxy resin and aminosiloxane capable of improving the binding force are introduced into a paint system, amino in the aminosiloxane is consumed and more hydroxyl is generated through the polymerization reaction of an aminosiloxane coupling agent and the epoxy resin, so that the improvement of the binding force is ensured, and the adverse effect on the performance after the monoamino of the coupling agent and the monohydroxy of the epoxy resin react with isocyanate is avoided.

Preferably, the organic silicon modified epoxy resin is prepared by the following method: decompressing and dehydrating the epoxy resin for 2-2.5h at 100-120 ℃, and removing water to inhibit the hydrolysis of-Si-OR; adding an aminosiloxane coupling agent, and reacting for 4-5h at 100-120 ℃ to obtain the organic silicon modified epoxy resin; preferably, the hydroxyl functionality of the silicone-modified epoxy resin averages 2 to 2.5 and the mass ratio of epoxy resin to aminosiloxane coupling agent is 1 (0.5 to 0.7), ensuring an excess of epoxy resin and avoiding too much crosslinking of the product and increasing the viscosity too much.

Preferably, the epoxy resin is a solventless liquid bisphenol a type epoxy resin, bisphenol F type epoxy resin or novolac amine type epoxy resin having a viscosity of 5000cps or less.

Preferably, the aminosiloxane coupling agent adopts siloxane containing a single primary amino structure; preferably, the aminosiloxane coupling agent is gamma-aminopropyltriethoxysilane, gamma-aminopropyltrimethoxysilane, N-beta (aminoethyl) -gamma-aminopropyltriethoxysilane, 3-aminopropylmethyldiethoxysilane or 3-aminopropyltrimethoxysilane.

Preferably, the composite emulsifier comprises a cationic emulsifier and a nonionic emulsifier, wherein the cationic emulsifier and the nonionic emulsifier respectively account for 0.5-1.5% of the total mass of the component B; preferably, the composite emulsifier comprises Cetyl Trimethyl Ammonium Bromide (CTAB) and nonylphenol polyoxyethylene ether (NP-10). The purpose of adding the composite emulsifier is to prepare for dilution by adding water for reducing viscosity during construction.

Preferably, the antirust pigment adopts one or two of zinc phosphate and strontium phosphomolybdate, and is baked and dehydrated.

Preferably, the leveling agent is one or two of German Tego organosilicon leveling agents Glide410, wet270, KL245 and Glide 100.

Preferably, 2,2,4 trimethyl 1,3 pentanediol diisobutyrate or diisopropyl naphthalene is used as the diluent.

Preferably, the catalyst adopts organic tin or organic bismuth catalyst.

The salt spray resistant auxiliary agent is a SPP-Y100 product of Shaanxi Fermi new material application science and technology Limited company, is a liquid low-viscosity ammonium sulfonate salt type salt spray resistant auxiliary agent, has the viscosity of 100cps (20 ℃), and has the specific gravity of 1.0g/cm ³ . The assistant can form umbrella-shaped protection on the surface of a metal substrate, has three effects of strong barrier, adhesion improvement and corrosion resistance, has extremely high efficiency, can replace part of antirust pigment and can improve the integral antirust performance.

The invention uses siloxane containing amino to react with epoxy resin, the product is polyol containing hydroxyl, and is terminated by siloxane group. The reaction between polyol and isocyanate can be carried out at normal temperature without heating, and the reaction speed of the polyurethane coating is higher than that of epoxy, so that the construction efficiency can be improved. The siloxane blocked on the molecular chain can be hydrolyzed into a silanol structure and further polymerized into polysiloxane, so that the binding force and the corrosion resistance can be greatly improved. The pure water system contains water, the thickness of the spraying is not large, otherwise, the spraying is sagging or does not dry for a long time, and the like, and the system can realize thin coating by adding water and can also become an anticorrosive material system with 100 percent of solid content without adding water. The amount of the powder antirust pigment is reduced by adding a liquid salt spray resistant auxiliary agent, so that the viscosity is ensured not to be too high; and the antirust effect is improved by adopting the strontium phosphomolybdate antirust pigment with good antirust effect.

Compared with the prior art, the invention has the following beneficial effects:

1. no solvation is achieved. The anticorrosive paint disclosed by the invention does not contain a solvent and is a solvent-free system. During spraying construction, a proper amount of water can be added as a diluent to reduce the viscosity, and the water-based paint is prepared to facilitate the spraying construction. Special equipment can also be adopted, and the viscosity can be reduced by heating the raw materials, so that solvent-free and thick coating construction is realized.

2. And (5) the requirement of binding force. The binding force of polyurethane is generally lower than that of epoxy resin, the epoxy resin is basically considered as the material with the best binding force, and in an anticorrosive material, poor binding force means that the anticorrosive performance is not good, so that the sufficient binding force of a new system needs to be ensured. The invention adopts the reaction mode of siloxane modified epoxy resin and polyurethane, meets the requirement of the binding force, and the alkoxy of siloxane is hydrolyzed and polymerized into polysiloxane, thereby greatly improving the binding force.

3. Low viscosity requirements. The solvent or water is added to the solvent-based or water-based paint to reduce the viscosity, and the anticorrosive paint usually needs to add a large amount of zinc powder and antirust pigment to achieve a good anticorrosive effect, which inevitably results in increased viscosity and inconvenience in construction. In the invention, the anode is not sacrificed by adding a large amount of zinc powder to meet the requirement of good corrosion resistance, but a liquid anti-rust pigment which is a liquid salt spray resistant auxiliary agent is used for replacing part of powder anti-rust pigment, the anti-rust pigment adopts molybdenum strontium phosphate which has excellent anti-rust effect and can be added in a small amount to have good corrosion resistance, and meanwhile, a proper amount of zinc phosphate is added to have a synergistic corrosion resistance effect, so that the material which has excellent corrosion resistance and is easy to spray construction is obtained. Meanwhile, the compound emulsifier is added into the raw materials in advance, water can be added for dilution when the paint is used, the viscosity can be reduced by heating the raw materials for spraying construction, and the method can be used particularly when the thin coating is required.

4. The reaction of epoxy resins, aminosiloxane coupling agents and polyurethanes. Because the hydroxyl content in the low-viscosity low-molecular-weight epoxy resin is often very low, basically each epoxy molecule contains one hydroxyl group, even less than one hydroxyl group on average, and the low-viscosity low-molecular-weight epoxy resin becomes a monofunctional polyol. The presence of chain terminators in the reaction with the polyurethane is very disadvantageous for the properties. The amino siloxane is added for improving the binding force, the surface cleaning property, the corrosion resistance and the like, but the NCO reaction speed of the amino silane and the polyurethane is extremely high, so that the construction is not facilitated. Furthermore, aminosilicones are also monofunctional, and too much addition has a very adverse effect on the properties of the material. Some hydrophobic silicones tend to have poor compatibility with polyurethanes. In order to solve the problems, the invention adopts the steps that firstly, the epoxy groups of the aminosiloxane and the epoxy resin react, the amino group reacts, and simultaneously, the epoxy groups open rings to generate hydroxyl groups, thus generating the polyhydroxy silane modified epoxy resin which can be used as polyol to react with NCO stably, simultaneously, the alkoxy at the tail end of the product is hydrolyzed to generate silanol, and further, the silanol is polymerized by self-polymerization and the hydroxyl groups of the substrate, thus obtaining the improvement of adhesive force and the improvement of corrosion resistance.

5. And controlling the comprehensive cost. Whether a new technology has practical value and operability, wherein cost is also a key factor, is also needed. The anticorrosive paint of the invention can be cured at normal temperature without heating and curing after spraying, and is beneficial to saving energy. Meanwhile, a scheme of multi-coating of the zinc-rich primer and the intermediate paint of the micaceous iron is not used, and a one-step forming mode is adopted, so that the efficiency is improved, and the cost is further reduced.

6. The invention avoids the existence of water during the raw material synthesis, mainly aims to improve the storage stability and avoid the generation of hydrolysis, but water can be added during the use to reduce the viscosity, and the generation of hydrolysis is beneficial to the hydrolysis and polymerization of alkoxy. In order to obtain good water dilutability, the invention adopts a compound emulsifier.

Detailed Description

In order to make those skilled in the art better understand the technical solutions of the present invention, the technical solutions in the embodiments of the present invention are clearly and completely described below, and it is obvious that the described embodiments are only a part of the embodiments of the present invention, and not all embodiments. All other embodiments, which can be obtained by a person skilled in the art without making any creative effort based on the embodiments in the present invention, shall fall within the protection scope of the present invention.

Example 1

The component A comprises: covestro waterborne polyisocyanate curing agent Bayhydur XP2547 is selected, the viscosity is 570-730cps, and the NCO mass ratio is 22.5 +/-0.5%.

Preparation of the component B:

putting 46 parts of epoxy resin NPEF-170 (south Asia epoxy resin) into a reaction kettle, dehydrating under reduced pressure at 120 ℃ for 2 hours, adding 24 parts of gamma-aminopropyltriethoxysilane, reacting at 120 ℃ for 4 hours to obtain organosilicon modified epoxy resin, discharging and cooling.

16.6 parts of dried and dehydrated zinc phosphate antirust pigment, 1.5 parts of emulsifier CTAB, 1.5 parts of emulsifier nonylphenol polyoxyethylene ether (NP-10), 0.2 part of flatting agent KL245, 5 parts of salt spray resistant additive SPP-Y100, 0.2 part of catalyst dibutyltin dilaurate (T12) and 5 parts of diluent 2, 4-trimethyl-1, 3-pentanediol diisobutyrate (TXIB) are added into the organic silicon modified epoxy resin, stirred uniformly and then put into a sand mill for grinding, and the material is discharged when the test fineness reaches 15-20 mu m.

The anticorrosive paint of the embodiment is prepared from the following components in parts by mass, wherein A is B, water = 1.6.

The properties of the anticorrosive paint coating of this example are shown in table 1:

TABLE 1

Item	Numerical value
		Adhesion force, MPa	12.6
Salt spray resistance, hr	2400 (thickness 100 μm)
		Operational time，min	40
Superficial dry time, min	20
		Impact resistance, cm	56
Film thickness of one pass, μm	40

Example 2

The component A comprises: aqueous isocyanate curing agent WD-8200 (100% solids, 2500cps, 21% NCO by mass) from Guangdong Asahi chemical industries, ltd.

Preparation of the component B:

43 parts of epoxy resin NPEF-175 (south Asia epoxy resin) is put into a reaction kettle, decompressed and dehydrated for 2 hours at 120 ℃, 22 parts of gamma-aminopropyltrimethoxysilane is added to react for 4 hours at 120 ℃ to obtain the epoxy resin polyol modified by organosilicon, and the material is discharged and cooled.

10.8 parts of dried and dehydrated zinc phosphate antirust pigment, 6 parts of dried and dehydrated strontium phosphomolybdate antirust pigment, 1 part of emulsifier CTAB, 1 part of emulsifier NP-10, 0.1 part of flatting agent KL245, 6 parts of salt spray resistant additive SPP-Y100, 0.1 part of catalyst dibutyltin dilaurate (T12) and 10 parts of diluent diisopropylnaphthalene are put into organic silicon modified epoxy resin, stirred uniformly and then put into a sand mill for grinding, and the material is discharged when the test fineness reaches 15-20 mu m.

The anticorrosive paint of the embodiment comprises the following components in parts by mass, A: B: water = 1.6.

The properties of the anticorrosive paint coating of this example are shown in table 2:

TABLE 2

Parameter(s)	Numerical value
		Adhesion force, MPa	10.8
Salt spray resistance, hr	2800 (thickness 100 μm)
		Operable time, min	40
Surface drying time, min	21
		Impact resistance, cm	60
Film thickness of one pass, μm	36

Example 3

The component A comprises: covestro XP 2655 with a viscosity of 3000cps and an NCO mass ratio of 21% is selected.

Preparation of the component B:

40 parts of epoxy resin NPEF-176 (south Asia epoxy resin) is put into a reaction kettle, decompressed and dehydrated for 2 hours at 120 ℃, 26 parts of N-beta (aminoethyl) -gamma-aminopropyltrimethoxysilane are added, the reaction is carried out for 4 hours at 120 ℃, the epoxy resin polyol modified by organic silicon is obtained, and the material is discharged and cooled.

15 parts of dried and dehydrated zinc phosphate antirust pigment, 5 parts of dried and dehydrated strontium phosphomolybdate antirust pigment, 1 part of emulsifier CTAB, 0.5 part of emulsifier NP-10, 0.1 part of flatting agent KL245, 5 parts of salt mist resistant additive SPP-Y100, 0.1 part of catalyst dibutyltin dilaurate (T12) and 7.3 parts of diluent diisopropylnaphthalene are put into the organic silicon modified epoxy resin, stirred uniformly and put into a sand mill for grinding, and the material is discharged when the testing fineness reaches 15-20 mu m.

The anticorrosive paint of the embodiment is prepared by heating raw materials to 40-50 ℃ according to the mass ratio of A: B = 1.

The properties of the anticorrosive paint coating of this example are shown in table 3:

TABLE 3

Item	Numerical value
		Adhesion force, MPa	14.8
Salt spray resistance, hr	2950 (thickness 100 μm)
		Application time, min	30
Superficial dry time, min	30
		Impact resistance, cm	50
Film thickness of one pass, μm	80

Example 4

And (2) component A: covestro aqueous polyisocyanate curing agent Bayhydur XP2547 with viscosity of 570-730cps and NCO mass ratio of 22.5 +/-0.5 percent is selected.

Preparation of the component B:

52 parts of epoxy resin NPEF-170 (south Asia epoxy resin) is put into a reaction kettle, decompressed and dehydrated for 2 hours at 110 ℃, added with 33 parts of 3-aminopropyl methyl diethoxysilane and reacted for 4 hours at 110 ℃ to obtain the epoxy resin polyol modified by organosilicon, and the material is discharged and cooled.

5 parts of dried and dehydrated zinc phosphate antirust pigment, 0.5 part of emulsifier CTAB, 0.5 part of emulsifier NP-10, 0.1 part of flatting agent Glide410, 2 parts of salt spray resistant additive SPP-Y100, 0.1 part of organic bismuth catalyst Bicat8118 and 6.8 parts of diluent diisopropyl naphthalene are added into the organic silicon modified epoxy resin, stirred uniformly and then put into a sand mill for grinding, and the material is discharged when the testing fineness reaches 15-20 mu m.

The properties of the anticorrosive paint coating of this example are shown in table 4:

TABLE 4

Example 5

The component A comprises: the waterborne isocyanate curing agent of the Wuhanshi Quanxing new material science and technology company S101 has the viscosity of 2500cps and the NCO mass ratio of 21.3 percent.

Preparation of the component B:

40 parts of epoxy resin HTM5102 (a product of Saint Jack resin Co., ltd.) is put into a reaction kettle, decompressed and dehydrated for 2 hours at 110 ℃, added with 25 parts of N-beta (aminoethyl) -gamma-aminopropyltriethoxysilane, reacted for 4 hours at 120 ℃ to obtain the epoxy resin polyol modified by organic silicon, and discharged and cooled.

13.5 parts of dried and dehydrated zinc phosphate antirust pigment, 5 parts of dried and dehydrated strontium phosphomolybdate antirust pigment, 0.8 part of emulsifying agent CTAB, 0.7 part of emulsifying agent NP-10, 0.1 part of flatting agent Glide410, 5 parts of salt spray resistant additive SPP-Y100, 0.1 part of organic bismuth catalyst Bicat8118 and 9.8 parts of diluent diisopropyl naphthalene are put into the organic silicon modified epoxy resin, stirred uniformly and put into a sand mill for grinding, and the material is discharged when the test fineness reaches 15-20 mu m.

The anticorrosive paint of the embodiment is prepared from the following raw materials in a mass ratio of A: B =1:1, and is heated to 40-60 ℃.

The properties of the anticorrosive paint coating of this example are shown in table 5:

TABLE 5

Item	Numerical value
		Adhesion force, MPa	14.3
Salt spray resistance, hr	2450 (thickness 100 μm)
		Operable time, min	35
Surface drying time, min	36
		Impact resistance, cm	52
Film thickness of one pass, μm	80

According to the standard requirement of the steel structure anticorrosive paint for JG/T224-2007 buildings, the salt spray resistance time of the steel structure anticorrosive paint for buildings is required to be different from 200h to 1000h (the film thickness is 100 micrometers). The salt spray resistant time of the general water-based anticorrosive paint is required to be shorter, for example, the salt spray resistant time of 300h (the film thickness is 100 micrometers) is required in the standard HG/T4759-2014 water-based epoxy resin anticorrosive paint, and the salt spray resistant time of the water-based paint of the invention is greatly beyond the standard requirement according to the salt spray resistant time test result of the water-based paint of the examples 1-5.

Comparative example 1

The difference from example 3 is that: the salt spray resistant aid of the component B in example 3 was removed.

Preparation of the component B:

15 parts of dried and dehydrated zinc phosphate antirust pigment, 5 parts of dried and dehydrated strontium phosphomolybdate antirust pigment, 1 part of emulsifier CTAB, 0.5 part of emulsifier NP-10, 0.1 part of flatting agent KL245, 0.1 part of catalyst dibutyltin dilaurate (T12) and 7.3 parts of diluent diisopropylnaphthalene are put into organic silicon modified epoxy resin, stirred uniformly and then put into a sand mill for grinding, and the material is discharged when the tested fineness reaches 15-20 mu m.

The anticorrosive paint of the comparative example has the following use mass ratio of A: B = 1.9, and the raw materials are heated to 40-50 ℃.

The properties of the anticorrosive paint coating of this comparative example are shown in table 6:

TABLE 6

Item	Numerical value
		Adhesive force, MPa	14.7
Salt spray resistance, hr	2600 (thickness 100 μm)
		Available time, min	28
Superficial dry time, min	30
		Impact resistance, cm	50
Film thickness of one pass, μm	100

As can be seen from comparison with example 3, if no liquid salt spray resistant additive is added, not only the salt spray resistant time is reduced, but also the corrosion prevention effect is reduced; the viscosity of the system is higher, the thickness of one film forming is also increased, and the thin coating is not easy to realize.

The standard requirements for the anticorrosive coatings of the invention and the "HG/T3668-2009 zinc rich primer" are as shown in table 7:

TABLE 7 comparison of the product of the invention with that of HG/T3668-2009 zinc rich primer

As can be seen from the table, the salt spray resistance of the product of the invention is far higher than the relevant standard regulation of the zinc-rich primer, and the bonding force with the base material is also greatly improved, thus the product can completely replace the zinc-rich primer for corrosion prevention of steel structures.

In addition, according to the use regulation of the related epoxy zinc-rich primer of the 'JGJ/T251-2011 architectural steel structure anticorrosion technical regulation', at least two times of epoxy zinc-rich primer are regulated, then 1-2 times of epoxy micaceous iron intermediate paint is sprayed, and finally finish paint or fireproof paint is coated. Because the epoxy zinc-rich primer contains a large amount of zinc powder, the compactness is not good, and the binding force with the fireproof coating or the finish paint is not ideal, the epoxy micaceous iron intermediate paint is required to be transited, the compactness is improved, and the binding force is increased. The material has good compactness, can be directly coated with fireproof paint or finish paint without intermediate paint, has binding force which can completely meet the adhesive force requirement specified in the 'JG/T224-2007 steel structure anticorrosive paint for buildings' standard, reduces the construction layer number and improves the efficiency.

Although the present invention has been described in detail by way of reference to examples, the present invention is not limited thereto. Various equivalent modifications or substitutions can be made on the embodiments of the present invention by those skilled in the art without departing from the spirit and scope of the present invention, and these modifications or substitutions are within the scope of the present invention/any person skilled in the art can easily conceive of the changes or substitutions within the technical scope of the present invention. Therefore, the protection scope of the present invention shall be subject to the protection scope of the claims.

Claims

1. The silane modified epoxy waterborne polyurethane steel structure anticorrosive paint is characterized by comprising a component A and a component B, wherein the mass ratio of the component A to the component B is 1: (1.5-2.0); wherein the component A comprises a 100 percent solid content aqueous isocyanate curing agent; the component B comprises organic silicon modified epoxy resin, a composite emulsifier, an antirust pigment, a flatting agent, a salt spray resistant auxiliary agent, a catalyst and a diluent; the organic silicon modified epoxy resin accounts for 65-85% of the total mass of the component B, the composite emulsifier accounts for 1-3% of the total mass of the component B, the antirust pigment accounts for 5-20% of the total mass of the component B, the flatting agent accounts for 0.1-0.2% of the total mass of the component B, the salt spray resistant auxiliary agent accounts for 2-6% of the total mass of the component B, the catalyst accounts for 0.1-0.2% of the total mass of the component B, and the diluent accounts for 5-10% of the total mass of the component B.

2. The silane-modified epoxy-based waterborne polyurethane steel-structure anticorrosive paint as claimed in claim 1, wherein the waterborne isocyanate curing agent is a curing agent with NCO content of more than 20wt% and viscosity of less than 3000 cps; preferably, the aqueous isocyanate curing agent adopts an HDI curing agent, an IPDI curing agent or an MDI curing agent.

3. The silane-modified epoxy-based aqueous polyurethane steel-structured anticorrosive coating of claim 1, wherein the organosilicon-modified epoxy resin is prepared by the following method: decompressing and dehydrating the epoxy resin for 2-2.5h at 100-120 ℃, adding an amino siloxane coupling agent, and reacting for 4-5h at 100-120 ℃ to obtain the organic silicon modified epoxy resin; preferably, the hydroxyl functionality of the organosilicon modified epoxy resin is 2-2.5 on average, and the mass ratio of the epoxy resin to the aminosiloxane coupling agent is 1 (0.5-0.7).

4. The silane-modified epoxy-based aqueous polyurethane steel-structured anticorrosive paint according to claim 3, wherein the epoxy resin is a solvent-free liquid bisphenol A type epoxy resin, bisphenol F type epoxy resin or phenol amine type epoxy resin having a viscosity of 5000cps or less.

5. The silane-modified epoxy-based aqueous polyurethane steel structure anticorrosive paint according to claim 3, wherein the aminosiloxane coupling agent is siloxane containing a mono-primary amino structure; preferably, the aminosiloxane coupling agent is gamma-aminopropyltriethoxysilane, gamma-aminopropyltrimethoxysilane, N-beta (aminoethyl) -gamma-aminopropyltriethoxysilane, 3-aminopropylmethyldiethoxysilane or 3-aminopropyltrimethoxysilane.

6. The silane modified epoxy aqueous polyurethane steel-structure anticorrosive coating as claimed in claim 1, characterized in that the composite emulsifier comprises a cationic emulsifier and a nonionic emulsifier, wherein the cationic emulsifier and the nonionic emulsifier respectively account for 0.5-1.5% of the total mass of the component B; preferably, the composite emulsifier comprises cetyl trimethyl ammonium bromide and nonylphenol polyoxyethylene ether.

7. The silane-modified epoxy-based waterborne polyurethane steel structure anticorrosive paint of claim 1, wherein one or two of zinc phosphate and strontium phosphomolybdate after baking and dehydration are adopted as the antirust pigment.

8. The silane modified epoxy waterborne polyurethane steel-structure anticorrosive paint of claim 1, wherein the leveling agent is one or two of Germany Tego organosilicon leveling agents Glide410, wet270, KL245 and Glide 100.

9. The silane-modified epoxy-based aqueous polyurethane steel structural anticorrosive paint according to claim 1, wherein 2,2, 4-trimethyl-1, 3-pentanediol diisobutyrate or diisopropyl naphthalene is used as the diluent.

10. The silane modified epoxy waterborne polyurethane steel-structure anticorrosive paint of claim 1, wherein the catalyst is an organotin or organobismuth-based catalyst.