High-density thick coating type heavy anti-corrosion coating as well as preparation method and application thereof

Abstract

The invention relates to a high-density thick coating type heavy anti-corrosion coating and a preparation method and application thereof.The preparation method comprises the steps that S1, an epoxy resin part is prepared, specifically, S11, resorcinol diglycidyl ether is added into epoxy resin to obtain a solution A; s12, hydrolyzing amino silane and epoxy silane with a mixed solution of ethanol and water, and mixing the hydrolyzed solutions together to obtain a solution B; s13, adding the solution B into the solution A, firstly adding a catalyst, and then adding water to obtain a solution C; s14, adding microcrystalline graphite, nano silicon carbide, nano boron nitride and flaky mica into the solution C to obtain a solution D; s15, adding a dispersing agent, a wetting agent and a preservative into the solution D to obtain an epoxy resin part; s2, preparing a polyurea part: adding isocyanate and amine-terminated polyether into a reaction kettle, and heating to 40-50 DEG C; and then dropwise adding a catalyst to obtain a polyurea part. The anti-corrosion coating has very strong protection capability and is suitable for corrosion prevention in a severe environment.

Description

TECHNICAL FIELD

[0001] The application belongs to the technical field of corrosion protection, and relates to a kind of anticorrosive paint and its preparation method and application, especially to a kind of high density thick coating type heavy-duty anticorrosive paint and its preparation method and application. BACKGROUND

[0002] At present, in the field of marine environment and other heavy-duty anticorrosive areas, the anticorrosive paint almost follows the structure of epoxy paint as the bottom layer + transition layer + polyurethane topcoat. In this way, multi-layer brushing is needed. And if there is improvement, it is also from a single material, without composite idea, that is, the primer, transition paint and topcoat are integrated, with the advantages of each. Therefore, it is difficult to meet the anticorrosion demand in harsh environment.

[0003] Therefore, based on the defects of the prior art, a new type of anticorrosive paint suitable for marine environment and other heavy-duty anticorrosive areas needs to be developed. SUMMARY

[0004] The purpose of the present application is to overcome the shortcomings of the prior art, and to provide a kind of high density thick coating type heavy-duty anticorrosive paint and its preparation method and application, which has strong protection ability and is suitable for anticorrosion in harsh environment.

[0005] In order to achieve the above purpose, the present application provides the following technical scheme:

[0006] A preparation method of a high density thick coating type heavy-duty anticorrosive paint, characterized in that the high density thick coating type heavy-duty anticorrosive paint comprises an epoxy resin part and a polyurea part, and the preparation method comprises the following steps:

[0007] S1: preparing an epoxy resin part, which specifically comprises:

[0008] S11: adding resorcinol diglycidyl ether to the epoxy resin and stirring uniformly to obtain A solution, wherein the content of resorcinol diglycidyl ether in the epoxy resin is 5-15%;

[0009] S12: hydrolyzing amino silane coupling agent and epoxy silane coupling agent with a mixture of ethanol and water respectively, and mixing the hydrolyzed solutions together to obtain B solution;

[0010] S13: adding the above B solution to the above A solution and stirring, wherein the ratio of A solution to B solution is 98-102:1, and during the stirring process, first add 0.1%-0.8% of the total amount of A solution and B solution of catalyst, and then add 1%-10% of the total amount of A solution and B solution of water to obtain C solution;

[0011] S14: adding 2%-10% of microcrystalline graphite with a particle size of less than 16 microns, 10%-30% of nano silicon carbide, 2%-8% of nano boron nitride and 5%-10% of flaky mica to the C solution, and stirring to obtain a D solution;

[0012] S15: adding 0.3%-1% of dispersant, wetting agent and preservative to the D solution respectively to obtain an epoxy resin part;

[0013] S2: preparing a polyurea part, specifically, adding 16%-30% of isocyanate and 60%-80% of amino-terminated polyether into a reaction kettle, and heating to 40-50°C, continuously stirring during the heating process; then adding 0.05%-0.4% of catalyst dropwise and continuing to stir until the viscosity reaches 150-650 mpa.s, and stopping stirring to obtain a polyurea part.

[0014] Preferably, in S11, the stirring speed is 100-600 rpm and the stirring time is 5-10 minutes.

[0015] Preferably, in S12, the volume ratio of ethanol to water in the mixture of ethanol and water is 9:1, the amount of amino silane coupling agent and epoxy silane coupling agent is 0.1-2% of the mixture of ethanol and water during hydrolysis, and 0.1% of acetic acid is added to the mixture of ethanol and water during hydrolysis to adjust the pH to 4-5; at the same time, the solution after hydrolysis is mixed together and stirred at a speed of 100-500 rpm for 1 hour to obtain a B solution.

[0016] Preferably, in S13, the stirring speed is 100-600 rpm and the stirring time is 30 minutes, and the catalyst added is triethylamine or zinc octoate.

[0017] Preferably, in S14, the stirring time is 20 minutes.

[0018] Preferably, in S15, the dispersant added is any one of sodium hexametaphosphate, potassium tripolyphosphate, tetrapotassium pyrophosphate, acrylic acid-sulfonic acid copolymer or high molecular weight copolymer; the wetting agent added is organic silicon / fluorocarbon or phosphate ester wetting agent; and the preservative added is benzimidazole ester or isothiazolinone complex preservative.

[0019] Preferably, in S2, the catalyst added is tertiary amine catalyst and organotin catalyst, and the stirring time during heating is 20 minutes and the stirring time after adding catalyst is 10 minutes.

[0020] Further, the application also provides a high-density thick-coating heavy-duty anticorrosive paint, which is characterized in that it comprises an epoxy resin part and a polyurea part and is prepared by the preparation method as described above.

[0021] Furthermore, the application also provides the application of the high-density thick-coating heavy-duty anticorrosive paint as described above, which is characterized in that it comprises the following steps:

[0022] S1: mixing the epoxy resin part and the polyurea part together, wherein the ratio of the epoxy resin part to the polyurea part is 1:2-1:3, and adding a curing agent and an inhibitor, wherein the ratio of the curing agent to the epoxy resin part is 1:5-1:8, and the inhibitor accounts for 0.1%-2% of the epoxy resin part;

[0023] S2: brushing the mixed solution obtained in S1 onto the equipment to be anticorrosive.

[0024] Finally, the application further provides the application of the high-density thick-coating heavy-duty anticorrosive paint as described above, which is characterized in that it comprises the following steps:

[0025] S1: adding a curing agent to the epoxy resin part, wherein the ratio of the curing agent to the epoxy resin part is 1:5-1:8, and then brushing it onto the equipment to be anticorrosive to form an epoxy coating;

[0026] S2: after the epoxy coating is cured, brushing the polyurea part on the epoxy coating or immersing the epoxy coating in the polyurea part, wherein the ratio of the epoxy resin part to the polyurea part is 1:2-1:3.

[0027] In the application, the epoxy resin part and the polyurea part are not simply physically blended, but a unique two-phase structure, and the rationality is more reflected in the synergistic effect at the microscopic level, so the application has one or more of the following beneficial technical effects:

[0028] 1. Forced mutual compatibility and interface combination: during the formation of the coating, the two polymer networks penetrate and entangle each other when forming, but there is no covalent bond connection between them (which is the key difference from copolymers), this interpenetrating structure greatly increases the contact area between the two phases, producing a forced mutual compatibility effect, even if the two polymers are not compatible, they are also forced to closely combine together; at the same time, the strong mechanical interlocking and physical entanglement make the stress can be effectively transmitted between the two phases, avoiding the common phase separation and large-size interface defects in ordinary blends.

[0029] 2. Biphasic continuous structure and stress dispersion: In the present invention, a perfect biphasic continuous structure can be formed, i.e. both the epoxy phase and the polyurea phase are continuous three-dimensional networks. Thus, when the material is impacted by external force, the rigid epoxy network as the continuous phase bears the main load, while the flexible polyol network dispersed in it acts as a stress concentration point, absorbing a large amount of impact energy through its own yield, deformation, crazing and shear banding, etc., effectively preventing or passivating the propagation of microcracks. The combination of using the epoxy polymer network structure to provide strength and the polyurea polymer network structure to provide toughness and energy dissipation has obvious advantages.

[0030] 3. Densified network structure: In the present invention, the mutual penetration of the two networks significantly increases the crosslinking density of the entire system, and the molecular chain segment movement is more restricted, which directly leads to the material exhibiting higher strength, modulus, hardness, heat resistance and better permeation resistance (enhanced shielding effect on water, oxygen and ions) on the macroscopic level. BRIEF DESCRIPTION OF DRAWINGS

[0031] Figure 1 is a flow chart of the preparation method of the high-density thick-coated heavy-duty coating of the present invention. DETAILED DESCRIPTION

[0032] In order to make the objects, technical solutions and advantages of the embodiments of the present invention clearer, the technical solutions in the embodiments of the present invention will be described clearly and completely below in conjunction with the drawings in the embodiments of the present invention. Obviously, the described embodiments are only a part of the embodiments of the present invention, rather than all the embodiments. The components of the embodiments of the present invention described and shown in the drawings herein can be arranged and designed in various different configurations.

[0033] Therefore, the following detailed description of the embodiments of the present invention provided in the drawings is not intended to limit the scope of the claimed invention, but only represents selected embodiments of the present invention. Based on the embodiments in the present invention, all other embodiments obtained by those of ordinary skill in the art without making creative efforts fall within the scope of protection of the present invention.

[0034] The high-density thick-coating heavy-duty anticorrosive paint of the present application comprises an epoxy resin part and a polyurea part. The mechanical properties of the epoxy resin part are high modulus, high strength, high hardness, and excellent adhesion, but it is brittle, has insufficient toughness, poor weather resistance, and is prone to pulverization. The chemical properties of the epoxy resin part are excellent chemical resistance (especially acid, alkali, and solvent resistance), but it has poor impact resistance and cracking resistance. The polyurea part has extremely high elongation at break, excellent toughness, excellent water resistance, salt spray resistance, aging resistance, and ultraviolet resistance. The toughness of the polyurea part can toughen the rigidity of the epoxy resin part, achieve rigidity and flexibility, and obtain a material with high strength and toughness. The epoxy resin part can be used as a bottom layer or main body to provide strong basic adhesion, and the polyurea part can enhance the toughness of the overall adhesive layer, and the two parts are perfectly complementary. The interpenetrating network system of the two parts has good chemical resistance and excellent weather resistance, and widens the application environment.

[0035] Figure 1 A flow chart of the preparation method of the high-density thick-coating heavy-duty anticorrosive paint of the present application is shown. As shown in the flow chart, Figure 1 the preparation method of the high-density thick-coating heavy-duty anticorrosive paint of the present application comprises the following steps:

[0036] S1: Preparation of an epoxy resin part.

[0037] In the present application, the preparation of the epoxy resin part specifically comprises:

[0038] S11: Preparation of A solution.

[0039] Resorcinol diglycidyl ether is added to the epoxy resin and stirred uniformly to obtain the A solution, wherein the resorcinol diglycidyl ether accounts for 5-15% of the epoxy resin.

[0040] The stirring is low-speed stirring, the stirring speed is 100-600 revolutions per minute, and the stirring time is 5-10 minutes.

[0041] In the present application, the epoxy groups of the resorcinol diglycidyl ether undergo ring-opening reaction with the hydroxyl groups (-OH) on the molecular chain of the epoxy resin to grow longer polyether segments, so as to reduce the viscosity while retaining the epoxy active groups (not completely reacted) for subsequent modification.

[0042] S12: Preparation of B solution.

[0043] The amino silane coupling agent and the epoxy silane coupling agent are hydrolyzed with a mixture of ethanol and water, and the hydrolyzed solutions are mixed together to obtain the B solution.

[0044] The volume ratio of ethanol to water in the mixture of ethanol and water is 9:1. The hydrolysis of amino silane coupling agent and epoxy silane coupling agent accounts for 0.1-2% of the mixture of ethanol and water. And 0.1% of acetic acid is added to the mixture of ethanol and water during the hydrolysis process to adjust the pH to 4-5. At the same time, the solution after hydrolysis is mixed together and stirred at a low speed of 100-500 rpm for 1 hour to obtain the B solution.

[0045] S13: Preparation of C solution.

[0046] The above B solution is added to the above A solution and stirred. The ratio of A solution to B solution is 98-102:1, and 0.1%-0.8% of catalyst is added to the total amount of A solution and B solution before adding 1%-10% of water to the total amount of A solution and B solution during the stirring process to obtain the C solution.

[0047] The stirring speed is 100-600 rpm and the stirring time is 30 minutes. And the added catalyst is triethylamine or zinc octoate.

[0048] In the present application, through step S13, the complete hydrolysis of siloxane groups can be ensured.

[0049] S14: Preparation of D solution.

[0050] The particle size of the microcrystalline graphite is less than 16 microns, the nano silicon carbide is 10%-30% of the C solution, the nano boron nitride is 2%-8% of the C solution, and the flaky mica is 5%-10% of the C solution. Stirring is uniform to obtain the D solution.

[0051] The stirring time is 20 minutes.

[0052] In the present application, the combination of micro-nano and dense structure is established by the combination of flaky, spherical and nano, which makes the water molecule penetration path longer and plays a shielding role. At the same time, the inertness of non-metallic materials fundamentally eliminates electrochemical corrosion, which is better than metal materials.

[0053] S15: Obtain the epoxy resin part.

[0054] The dispersant, wetting agent and preservative are added to the D solution, respectively accounting for 0.3%-1% of the D solution to obtain the epoxy resin part.

[0055] The dispersant is any one of sodium hexametaphosphate, potassium tripolyphosphate, tetrapotassium pyrophosphate, acrylic acid-sulfonic acid copolymer or high molecular weight copolymer; the wetting agent is organic silicon / fluorocarbon or phosphate ester wetting agent; and the preservative is benzimidazole ester or isothiazolinone complex preservative.

[0056] S2: preparing a polyurea part.

[0057] Add 16%-30% of isocyanate and 60%-80% of terminal amino polyether into a reaction kettle, and heat to 40-50℃, continuously stir during the heating process; then add 0.05%-0.4% of catalyst dropwise and continue to stir until the viscosity reaches 150-650mpa.s, stop stirring, to obtain a polyurea part.

[0058] Among them, the added catalyst is a tertiary amine catalyst and an organic tin catalyst, and the stirring time during the heating process is 20 minutes, and the stirring time after adding the catalyst is 10 minutes.

[0059] In the present application, isocyanate provides -NCO groups, which react with -NH2 provided by terminal amino polyether to form urea bonds. Terminal amino polyether provides flexible long chains, endows toughness, and its amino group (-NH2) is a reactive site that can react with -NCO groups provided by isocyanate to form urea bonds. At the same time, organic tin catalyst helps to stabilize the reaction, and tertiary amine catalyst catalyzes the formation of urea bonds.

[0060] The high-density thick-coated heavy-duty anticorrosive coating prepared in the present application can be used for equipment corrosion prevention in marine environment.

[0061] In the present application, there are two methods for preparing and controlling the morphology of the polyurea-epoxy interpenetrating entangled polymer network system:

[0062] 1. One-step interpenetrating entanglement: mix the epoxy resin part and its curing agent, and the polyurea part at the same time, and then let the amine / anhydride curing reaction of the epoxy and the isocyanate-amino reaction of the polyurea proceed at the same time. This method requires precise matching and control of the reaction rate.

[0063] 2. Two-step interpenetrating entanglement: first synthesize the first network (let the epoxy resin part cure first), then immerse it in a solution of the second monomer (in the polyurea part), and let the second monomer polymerize inside the formed epoxy network to form an interpenetrating structure. This method is easier to control the phase morphology.

[0064] Therefore, the application method of the high-density thick-coated heavy-duty anticorrosive coating of the present application also has two methods.

[0065] The first application includes the following steps:

[0066] S1: mix the epoxy resin part and the polyurea part together, wherein the ratio of the epoxy resin part to the polyurea part is 1:2-1:3, and add a curing agent and an inhibitor, wherein the ratio of the curing agent to the epoxy resin part is 1:5-1:8, and the inhibitor accounts for 0.1%-2% of the epoxy resin part.

[0067] In which, since the reaction of the polyurea part is slower than that of the epoxy resin part, the relative rates of the two reactions can be ensured to be similar by adding inhibitors such as acyl chloride and phosphoric acid.

[0068] S2: The mixed solution obtained in S1 is brushed on the equipment to be preserved.

[0069] The second application comprises the following steps:

[0070] S1: A curing agent is added to the epoxy resin part, wherein the ratio of the curing agent to the epoxy resin part is 1:5-1:8, and then the mixture is brushed on the equipment to be preserved to form an epoxy coating.

[0071] S2: After the epoxy coating is cured, the polyurea part is brushed on the epoxy coating or the epoxy coating is immersed in the polyurea part, so that the polyurea part is fully swelled and penetrates into the interior of the epoxy network to form a polyurea network. In which, the ratio of the epoxy resin part to the polyurea part is 1:2-1:3 when brushing or immersing.

[0072] The polyurea-epoxy interpenetrating network system of the high-density thick-coating heavy-duty anticorrosive coating of the present application is not a simple conceptual superposition, but is based on the deep performance complementarity between the two high-performance polymers, and realizes the synergistic effect of rigidity and flexibility on the nanometer / micrometer scale through the unique interpenetrating network structure, and finally shows a leap in comprehensive performance on the macroscopic level. The system is a method for realizing performance optimization in the field of high polymer material design through physical and chemical methods, and provides a powerful solution for harsh environments such as seawater corrosion resistance, ultraviolet aging resistance, and wave impact resistance of ships and offshore platforms, strong adhesion and seamless, impact resistance, and crack resistance of concrete bridges, chemical resistance and permeability resistance of petroleum and chemical facilities.

[0073] The above embodiments of the present application are merely examples for clearly illustrating the present application, and are not intended to limit the embodiments of the present application. Other different forms of changes or variations can be made by those skilled in the art on the basis of the above description. It is impossible to enumerate all the embodiments here. Any obvious changes or variations derived from the technical solutions of the present application still fall within the protection scope of the present application.

Claims

1. A method for producing a high-density thick-coat type heavy-duty coating material, characterized by, The high-density thick-coating heavy-duty coating comprises an epoxy resin part and a polyurea part, and the preparation method comprises the following steps: S1: preparing the epoxy resin part, which specifically comprises: S11: adding resorcinol diglycidyl ether into the epoxy resin and stirring uniformly to obtain an A solution, wherein the resorcinol diglycidyl ether accounts for 5-15% of the epoxy resin; S12: hydrolyzing the amino silane coupling agent and the epoxy silane coupling agent respectively with a mixture of ethanol and water and mixing the hydrolyzed solutions together to obtain a B solution; S13: adding the B solution into the A solution and stirring, wherein the ratio of the A solution to the B solution is 98-102:1, and during the stirring, 0.1%-0.8% of the catalyst based on the total amount of the A solution and the B solution is added first, and then 1%-10% of water based on the total amount of the A solution and the B solution is added, to obtain a C solution; S14: adding 2%-10% of microcrystalline graphite with a particle size of less than 16 microns, 10%-30% of nano silicon carbide, 2%-8% of nano boron nitride and 5%-10% of flaky mica based on the C solution into the C solution and stirring uniformly to obtain a D solution; S15: adding 0.3%-1% of the dispersant, the wetting agent and the preservative based on the D solution respectively into the D solution to obtain the epoxy resin part; S2: preparing the polyurea part, which specifically comprises: adding 16%-30% of isocyanate and 60%-80% of amino-terminated polyether into a reaction kettle and heating to 40-50℃, continuously stirring during the heating; then adding 0.05%-0.4% of the catalyst dropwise and continuing to stir until the viscosity reaches 150-650mpa.s, and stopping the stirring to obtain the polyurea part.

2. The method of producing a high-density thick-coat heavy-duty coating according to claim 1, characterized by, In S11, the stirring speed is 100-600rpm and the stirring time is 5-10 minutes.

3. The method of producing a high-density thick-coat heavy-duty coating according to claim 1, characterized by, In S12, the volume ratio of ethanol to water in the mixture of ethanol and water is 9:1, the amino silane coupling agent and the epoxy silane coupling agent each account for 0.1-2% of the mixture of ethanol and water during the hydrolysis, and 0.1% of acetic acid based on the mixture of ethanol and water is added during the hydrolysis to adjust the pH to 4-5; at the same time, the hydrolyzed solutions are mixed together and stirred at a speed of 100-500rpm for 1 hour to obtain the B solution.

4. The method of producing a high build heavy-duty coating according to claim 1, characterized in that, In S13, the stirring speed is 100-600rpm and the stirring time is 30 minutes, and the added catalyst is triethylamine or zinc octoate.

5. The method of producing a high build heavy-duty coating according to claim 1, wherein In S14, the stirring time is 20 minutes.

6. The method of producing a high build heavy-duty coating according to claim 1, wherein In S15, the added dispersant is any one of sodium hexametaphosphate, potassium tripolyphosphate, tetrapotassium pyrophosphate, acrylic acid-sulfonic acid copolymer or high molecular weight copolymer; the added wetting agent is an organic silicon / fluorocarbon or a phosphate ester wetting agent; and the added preservative is a benzimidazole ester or an isothiazolinone compound.

7. The method of producing a high build heavy-duty coating according to claim 1, wherein In S2, the added catalyst is a tertiary amine catalyst and an organic tin catalyst, and the stirring time during the heating is 20 minutes, and the stirring time after the catalyst is added is 10 minutes.

8. A high build heavy duty coating characterized in that, It comprises an epoxy resin part and a polyurea part and is prepared by the preparation method of any one of claims 1-7.

9. Use of a high build heavy duty coating material according to claim 8, characterized in that The method comprises the following steps: S1: mixing the epoxy resin part and the polyurea part together, wherein the ratio of the epoxy resin part to the polyurea part is 1:2-1:3, and adding a curing agent and an inhibitor, wherein the ratio of the curing agent to the epoxy resin part is 1:5-1:8, and the inhibitor accounts for 0.1%-2% of the epoxy resin part; S2: brushing the mixture obtained in S1 onto the equipment to be preserved.

10. Use of the high-density thick-coat heavy-duty coating material according to claim 8, characterized in that, The method comprises the following steps: S1: adding a curing agent to the epoxy resin part, wherein the ratio of the curing agent to the epoxy resin part is 1:5-1:8, and then brushing the mixture onto the equipment to be preserved to form an epoxy coating; S2: after the epoxy coating is cured, brushing the polyurea part on the epoxy coating, or immersing the epoxy coating in the polyurea part, wherein the ratio of the epoxy resin part to the polyurea part is 1:2-1:3.

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