A deep-sea pressure-resistant self-layering solvent-free coating and a preparation method thereof

Abstract

The application discloses a kind of deep sea pressure-resistant self-layering solvent-free paint and preparation method thereof.The coating includes mutually coordinated A, B component, the mass ratio of both (4-6):1;Component A includes epoxy resin, active diluent, solvent-free hyperdispersant, anticorrosive viscosity reducer, silicone defoamer, polyamide wax thixotropic agent, polytetrafluoroethylene powder, hydrophobic nanosilica, pigment, filler;Component B includes alicyclic amine curing agent, polyethylene imine, long carbon chain fatty amine, adhesion promoter.The coating of the application considers the excellent wet adhesion and hydrophobicity of coating through self-layering effect;Avoid the problem that traditional solvent-free coating causes high water permeability and high hydrophilicity due to high crosslinking density and high polarity, and high water molecule penetration and diffusion rate in paint film under high pressure condition, while avoiding the penetration and foaming problem caused by wet adhesion in deep sea environment due to common solvent-free coating, meet the long-term anticorrosion demand under deep sea high pressure environment.

Description

TECHNICAL FIELD

[0001] The present application relates to the field of chemical coatings, in particular to a deep-sea pressure-resistant self-layering solvent-free coating and a preparation method thereof. BACKGROUND

[0002] With the continuous development of deepwater oil and gas field development in the field of offshore oil and gas, the research on the corrosion and protection of metal materials in deep-sea environment is imminent. Deep sea generally refers to the marine environment below 2000m in depth. Compared with shallow sea, the pressure, temperature, dissolved oxygen and other factors of deep-sea environment have changed greatly. For example, with the increase of seawater depth, the hydrostatic pressure of seawater increases, the dissolved oxygen content decreases first and then increases, and reaches the minimum at about 1000m, and the temperature gradually decreases and remains constant at about 0℃ below 1000m. These factors mix together to form a deep-sea corrosion environment with high pressure, low temperature and low dissolved oxygen content. Under the deep-sea corrosion environment, the coating bears the alternating load of hydrostatic pressure, and the continuous "push-pull" effect will cause the cracking at the "coating-interface", which reduces the adhesion of the coating to the substrate and is one of the important reasons for the failure of the coating. At the same time, the high permeability of water in deep-sea environment will also increase the diffusion rate of water molecules in the coating, increase the water absorption of the coating, and cause the coating to lose adhesion, resulting in failure problems such as blistering and peeling. The characteristics of deep-sea corrosion environment cause the damage speed of traditional organic coating to increase in deep-sea environment, which affects the protective performance of the coating and greatly shortens the protective life of the traditional organic coating. Therefore, it is necessary to develop a deep-sea pressure-resistant coating with excellent long-term corrosion protection performance for related equipment and facilities in deep-sea environment. SUMMARY

[0003] In order to solve the above technical problems, the present application provides a deep-sea pressure-resistant self-layering solvent-free coating and a preparation method thereof. The coating has excellent deep-sea pressure-resistant corrosion resistance and meets the long-term corrosion protection requirements under deep-sea environmental conditions.

[0004] In the first aspect, the present application provides a deep-sea pressure-resistant self-layering solvent-free coating, which is realized by the following technical scheme.

[0005] The deep-sea pressure-resistant self-layering solvent-free coating is composed of two components A and B, and the weight ratio of A component to B component is (4-6):1.

[0006] The A component includes the following components by weight: epoxy resin 30-40 parts; A-type active diluent 10-15 parts; B-type active diluent 10-15 parts; solvent-free super dispersant 1-1.5 parts; anti-corrosion viscosity reducer 0.5-1.5 parts; organic silicon defoaming agent 0.5-1 part; polyamide wax thixotropic agent 0.5-1 part; polytetrafluoroethylene powder 0.5-1 part; hydrophobic nano-silicon dioxide 0.5-1 part; pigment 10-20 parts; filler 10-20 parts.

[0007] The B component includes the following components by weight: alicyclic amine curing agent 50-70 parts; polyethyleneimine 5-10 parts; long carbon chain aliphatic amine 5-10 parts; adhesion promoter 3-5 parts.

[0008] Further, in the A component, the epoxy resin is selected from any one or a combination of bisphenol F epoxy resin and phenolic epoxy resin.

[0009] Further, in the A component, the epoxy resin has a functionality of 2.1-2.4.

[0010] Further, in the A component, the A-type active diluent is selected from one or a combination of a trifunctional glycidyl ether and a tetrafunctional glycidyl ether, specifically, the trifunctional glycidyl ether is trimethylol ethane triglycidyl ether, and the tetrafunctional glycidyl ether is pentaerythritol glycidyl ether.

[0011] Further, in the A component, the B-type active diluent is selected from one or a combination of monofunctional glycidyl ethers containing 8 or more long carbon chains, specifically, the monofunctional glycidyl ethers containing 8 or more long carbon chains include C8-10 alkyl glycidyl ether and C12-14 alkyl glycidyl ether.

[0012] Further, in the A component, the anti-corrosion viscosity reducer is selected from a functional silane dispersant. Specifically, the functional silane dispersant is SIVO 240 from Wacker.

[0013] Further, in the A component, the pigment is selected from any one or a combination of rutile titanium dioxide and carbon black.

[0014] Further, in the A component, the filler is selected from a combination of any two or more of silicon powder, feldspar powder, and mica powder.

[0015] Further, in the B component, the alicyclic amine curing agent is selected from any one or a combination of 1,3-cyclohexanedimethylamine, cyclohexanediamine, isophorone diamine, 4,4'-diaminodicyclohexylmethane, and a modified product of a polycyclic alicyclic amine.

[0016] Further, in the B component, the polyethyleneimine is selected from any one or a combination of polyethyleneimines with a molecular weight of 300-600.

[0017] Further, in the B component, the long carbon chain aliphatic amine is selected from one or a combination of aliphatic diamines containing a long carbon chain of 6-9 C atoms, specifically, the aliphatic diamines containing a long carbon chain of 6-9 C atoms include trimethylhexamethylene diamine and 2-methyl-1,5-pentanediamine.

[0018] Further, in the B component, the adhesion promoter is selected from any one or a combination of bis(3-triethoxysilyl)propylamine and bis(3-trimethoxysilyl)propylamine.

[0019] In a second aspect, the application provides a preparation method of the deep-sea pressure-resistant self-layering solvent-free coating, which is achieved by using the following technical scheme.

[0020] The preparation method of the deep-sea pressure-resistant self-layering solvent-free coating comprises the following steps:

[0021] S1. Preparation of the A component

[0022] i. Mix the epoxy resin and the A-type active diluent, and uniformly stir and disperse at 800-1200 rpm, then add the corrosion-resistant viscosity reducer, the silicone defoaming agent, and the polyamide wax thixotropic agent, and uniformly stir and disperse at 1200-18000 rpm to obtain a mixed solution i;

[0023] ii. Add the pigments and fillers to the mixed solution i, and uniformly stir and disperse at 1200-18000 rpm, and control the temperature at 55-60℃ and the fineness to be less than 80 um during the dispersion process to obtain a mixed solution ii;

[0024] iii. Add the solvent-free superdispersant to the B-type active diluent, and uniformly stir and disperse at 600-800 rpm, then add the polytetrafluoroethylene powder and the hydrophobic nano-silicon dioxide, and uniformly stir and disperse at 1200-2000 rpm to obtain a mixture iii;

[0025] iv. Mix the mixed solution ii and the mixture iii, and uniformly stir and disperse at 800-1200 rpm to obtain the A component;

[0026] S2. Preparation of the B component

[0027] Mix the alicyclic amine curing agent, the polyethylene imine, and the long-carbon-chain aliphatic amine, and uniformly stir and disperse at 800-1200 rpm, then add the adhesion promoter, and uniformly stir and disperse at 600-1000 rpm to obtain the B component;

[0028] S3. When used, the A component and the B component are mixed at a ratio of (4-6):1.

[0029] The application has the following beneficial effects.

[0030] The present application provides a pressure-resistant self-layering solvent-free coating applicable to deep-sea environment, which produces self-layering effect during the curing process after coating application, and the final cured paint film has stronger polarity in the part of the bottom layer contacting the substrate, ensuring excellent wet adhesion between the coating and the substrate, avoiding the failure behaviors such as blistering of the coating due to water penetration into the "coating-substrate" interface under the action of high pressure in deep sea; at the same time, the surface layer of the cured paint film has lower polarity and more excellent hydrophobicity, providing excellent shielding effect, greatly reducing the diffusion rate of water molecules penetrating into the coating film. In addition, the middle part of the cured paint film has higher crosslinking density and curing strength, ensuring excellent physical and mechanical properties of the coating under high pressure conditions.

[0031] The self-layering solvent-free coating of the present application realizes micro-phase layering during the curing process after coating application by the difference in polarity and surface tension of the active diluent, amine curing agent in the coating formula. When the coating A, B components are mixed and applied, during the curing process, the trifunctional glycidyl ether, tetrafunctional glycidyl ether and polyethyleneimine with high polarity and high surface tension migrate more to the surface of the substrate and cure, the large number of ether bond structures in the trifunctional glycidyl ether, tetrafunctional glycidyl ether and the network tertiary amine structure in the polyethyleneimine provide excellent adsorption effect on the substrate, ensuring excellent adhesion between the coating and the substrate, especially when water molecules reach the "coating-substrate" interface, ensuring that the coating is not replaced by water molecules, maintaining excellent wet adhesion. At the same time, the monofunctional glycidyl ether with carbon chain of 8 or more C atoms and the aliphatic diamine with carbon chain of 6-8 C atoms in the coating have lower surface tension and polarity, migrate to the surface and crosslink during curing, and the surface layer of the paint film formed has excellent hydrophobicity due to low polarity and low content of hydrophilic groups; in addition, the polytetrafluoroethylene powder and nano silicon dioxide with hydrophobic properties migrate to the surface of the coating together through the stabilizing effect, further improving the hydrophobicity of the cured coating. The phenolic epoxy resin and modified alicyclic amine curing agent in the self-layering solvent-free coating are enriched in the middle part of the coating, giving the cured paint film high crosslinking density and coating strength, ensuring that the physical and mechanical properties of the coating meet the requirements of deep-sea high pressure resistance.

[0032] Compared with traditional solvent-free coatings for deep-sea high pressure environment, the self-layering solvent-free coating of the present application takes into account the excellent wet adhesion and hydrophobicity of the coating through self-layering effect; avoids the problem of strong hydrophilicity of the coating film of traditional solvent-free coatings due to high crosslinking density and high polarity, high penetration and diffusion rate of water molecules in the paint film under high pressure conditions, and the problem of permeability blistering caused by wet adhesion of common solvent-free coatings used in deep-sea environment, meeting the long-term corrosion prevention requirements in deep-sea environment. DETAILED DESCRIPTION

[0033] The patent application is further illustrated below in conjunction with the examples.

[0034] The materials used in the preparation process in the following examples are not specially mentioned and are not further treated, and are purchased through commercial channels.

[0035] Example 1

[0036] A preparation method of a deep-sea pressure-resistant self-layering solvent-free coating, comprising the following steps:

[0037] (1) Preparation of A component

[0038] (i) 30 g of NPEF170 bisphenol F epoxy resin, 15 g of pentaerythritol glycidyl ether were added, stirred at 1000 rpm for 20 min, then 1.5 g of SIVO240 anti-corrosion viscosity reducer, 0.5 g of BYK-1799 silicone defoamer, 0.5 g of polyamide wax Opitma were added, stirred at 1500 rpm for 45 min, to obtain a step i mixture;

[0039] (ii) 18 g of titanium white powder R-258, 0.1 g of special black 6 carbon black, 10 g of mica powder, 5 g of silicon powder, 4 g of feldspar powder were added to the step i mixture, and stirred at 1500 rpm for 45 min to obtain a step ii mixture;

[0040] (iii) 14 g of C8-10 alkyl glycidyl ether, 1 g of BYK 2155 solvent-free hyperdispersant were added, stirred at 600 rpm for 20 min, 0.5 g of polytetrafluoroethylene powder, 1 g of hydrophobic nano-silicon dioxide were added, stirred at 1500 rpm for 45 min to obtain a step iii mixture;

[0041] (iv) The step ii mixture was mixed with the step iii mixture, stirred at 1000 rpm for 45 min to obtain the A component.

[0042] (2) Preparation of B component

[0043] (i) 10 g of polyethyleneimine SP-006, 55 g of alicyclic amine curing agent Ancmaine 2280, 10 g of trimethylhexamethylene diamine were added, stirred at 1000 rpm for 15 min, then 3 g of bis(3-trimethoxysilyl)propylamine was added, stirred at 800 rpm for 15 min to obtain the B component.

[0044] (3) The A component and the B component were mixed in a mass ratio of 4:1.

[0045] Example 2

[0046] A preparation method of a deep-sea pressure-resistant self-layering solvent-free coating, comprising the following steps:

[0047] (1) Preparation of A component

[0048] (i) 35 g of EPALLOY 8240 phenolic epoxy resin, 15 g of trimethylol ethane triglycidyl ether were added, stirred at 800 rpm for 30 min, then 1.2 g of SIVO 240 anti-corrosion viscosity reducer, 0.8 g of BYK-1799 silicone defoamer, 0.7 g of polyamide wax Opitma were added, stirred at 1200 rpm for 60 min to obtain a step i mixture;

[0049] (ii) 15 g of titanium white powder R-258, 0.3 g of special black 6 carbon black, 8 g of mica powder, 4 g of silicon powder, 4 g of feldspar powder were added to the step i mixture, stirred at 1200 rpm for 60 min to obtain a step ii mixture;

[0050] (iii) 6 g of C8-10 alkyl glycidyl ether, 6 g of C12-14 alkyl glycidyl ether, 1.2 g of BYK 2155 solvent-free hyperdispersant were added, stirred at 800 rpm for 10 min, then 1 g of polytetrafluoroethylene powder, 0.5 g of hydrophobic nano-silicon dioxide were added, stirred at 2000 rpm for 30 min to obtain a step iii mixture;

[0051] (iv) The step ii mixture was mixed with the step iii mixture, stirred at 800 rpm for 60 min to obtain the A component.

[0052] (2) Preparation of B component

[0053] (i) 4 g of polyethyleneimine SP-006, 4 g of polyethyleneimine SP-003, 60 g of alicyclic amine curing agent Ancmaine 2280, 6 g of trimethylhexamethylene diamine were added, stirred at 800 rpm for 20 min, then 2 g of bis(3-trimethoxysilyl)propylamine, 2 g of bis(3-triethoxysilyl)propylamine were added, stirred at 600 rpm for 20 min to obtain the B component.

[0054] (3) The A component and the B component were mixed in a mass ratio of 6:1.

[0055] Example 3

[0056] A preparation method of a deep-sea pressure-resistant self-layering solvent-free coating, comprising the following steps:

[0057] (1) Preparation of A component

[0058] (i) 20 g of NPEF170 bisphenol F epoxy resin, 20 g of EPALLOY8240 phenolic epoxy resin, 6 g of pentaerythritol glycidyl ether, 6 g of trimethylol ethane triglycidyl ether were added, stirred at 1200 rpm for 15 min, then 0.8 g of SIVO240 anti-corrosion viscosity reducer, 1 g of BYK-1799 silicone defoamer, 1 g of polyamide wax Opitma were added, stirred at 1800 rpm for 30 min to obtain a step i mixture;

[0059] (ii) 10 g of titanium white powder R-258, 0.5 g of special black 6 carbon black, 6 g of mica powder, 6 g of silicon powder, 6 g of feldspar powder were added to the step i mixture, stirred at 1800 rpm for 30 min to obtain a step ii mixture;

[0060] (iii) 10 g of C12-14 alkyl glycidyl ether, 1.5 g of BYK 2155 solvent-free hyperdispersant were added, stirred at 700 rpm for 15 min, then 0.6 g of polytetrafluoroethylene powder, 0.6 g of hydrophobic nano-silicon dioxide were added, stirred at 1200 rpm for 60 min to obtain a step iii mixture;

[0061] (iv) The step ii mixture was mixed with the step iii mixture, stirred at 1200 rpm for 30 min to obtain component A.

[0062] (2) Preparation of component B

[0063] (i) 5 g of polyethyleneimine SP-003, 65 g of alicyclic amine curing agent Ancmaine 2280, 5 g of trimethylhexamethylene diamine were added, stirred at 1200 rpm for 10 min, then 5 g of bis(3-triethoxysilyl)propylamine was added, stirred at 1000 rpm for 10 min to obtain component B.

[0064] (3) Components A and B were mixed in a mass ratio of 5:1.

[0065] Comparative Example 1

[0066] A method for preparing a coating, comprising the following steps:

[0067] (1) Preparation of component A

[0068] (i) 30 g of NPEF170 bisphenol F epoxy resin, 15 g of pentaerythritol glycidyl ether were added, stirred at 1000 rpm for 20 min, then 1.5 g of SIVO240 anti-corrosion viscosity reducer, 0.5 g of BYK-1799 silicone defoamer, 0.5 g of polyamide wax Opitma were added, stirred at 1500 rpm for 45 min to obtain a step i mixture;

[0069] (ii) 18 g of titanium white powder R-258, 0.1 g of special black 6 carbon black, 10 g of mica powder, 5 g of silicon powder, and 4 g of feldspar powder were added to the mixture of step i, and stirred at 1500 rpm for 45 min to obtain a mixture of step ii;

[0070] (iii) 14 g of pentaerythritol glycidyl ether, 1 g of BYK 2155 solvent-free hyperdispersant were added, and stirred at 600 rpm for 20 min, 0.5 g of polytetrafluoroethylene powder and 1 g of hydrophobic nano-silicon dioxide were added, and stirred at 1500 rpm for 45 min to obtain a mixture of step iii;

[0071] (iv) The mixture of step ii was mixed with the mixture of step iii, and stirred at 1000 rpm for 45 min to obtain component A.

[0072] (2) Preparation of component B

[0073] (i) 10 g of polyethyleneimine SP-006, 55 g of alicyclic amine curing agent Ancmaine 2280, 10 g of trimethylhexamethylene diamine, 3 g of bis(3-trimethoxysilyl)propylamine were added, and stirred at 1000 rpm for 15 min, and then stirred at 800 rpm for 15 min to obtain component B.

[0074] (3) Component A and component B were mixed in a mass ratio of 4:1.

[0075] Comparative example 2

[0076] A method for preparing a coating, comprising the following steps:

[0077] (1) Preparation of component A

[0078] (i) 35 g of EPALLOY 8240 phenolic epoxy resin, 7.5 g of C8-10 alkyl glycidyl ether, 7.5 g of C12-14 alkyl glycidyl ether were added, and stirred at 800 rpm for 30 min, 1.2 g of SIVO 240 anti-corrosion viscosity reducer, 0.8 g of BYK-1799 silicone defoamer, and 0.7 g of polyamide wax Opitma were added, and stirred at 1200 rpm for 60 min to obtain a mixture of step i;

[0079] (ii) 15 g of titanium white powder R-258, 0.3 g of special black 6 carbon black, 8 g of mica powder, 4 g of silicon powder, and 4 g of feldspar powder were added to the mixture of step i, and stirred at 1200 rpm for 60 min to obtain a mixture of step ii;

[0080] (iii) 6 g C8-10 alkyl glycidyl ether, 6 g C12-14 alkyl glycidyl ether, 1.2 g BYK 2155 solvent-free hyperdispersant were added, stirred at 800 rpm for 10 min, 1 g polytetrafluoroethylene powder, 0.5 g hydrophobic nano-silica were added, stirred at 2000 rpm for 30 min, to obtain a step iii mixture;

[0081] (iv) The step ii mixture was mixed with the step iii mixture, stirred at 800 rpm for 60 min, to obtain component A.

[0082] (2) Preparation of component B

[0083] (i) 4 g polyethyleneimine SP-006, 4 g polyethyleneimine SP-003, 60 g alicyclic amine curing agent Ancmaine 2280, 6 g trimethylhexamethylene diamine were added, stirred at 800 rpm for 20 min, then 2 g bis(3-trimethoxysilyl)propylamine, 2 g bis(3-triethoxysilyl)propylamine were added, stirred at 600 rpm for 20 min, to obtain component B.

[0084] (3) Component A and component B were mixed in a mass ratio of 6:1.

[0085] Comparative Example 3

[0086] A method for preparing a coating, comprising the following steps:

[0087] (1) Preparation of component A

[0088] (i) 20 g NPEF170 bisphenol F epoxy resin, 20 g EPALLOY 8240 phenolic epoxy resin, 6 g pentaerythritol glycidyl ether, 6 g trimethylol ethane triglycidyl ether were added, stirred at 1200 rpm for 15 min, then 0.8 g SIVO 240 anti-corrosion viscosity reducer, 1 g BYK-1799 silicone defoamer, 1 g polyamide wax Opitma were added, stirred at 1800 rpm for 30 min, to obtain a step i mixture;

[0089] (ii) 10 g titanium white powder R-258, 0.5 g special black 6 carbon black, 6 g mica powder, 6 g silica powder, 6 g feldspar powder were added to the step i mixture, stirred at 1800 rpm for 30 min, to obtain a step ii mixture;

[0090] (iii) 10 g C12-14 alkyl glycidyl ether, 1.5 g BYK 2155 solvent-free hyperdispersant were added, stirred at 700 rpm for 15 min, 0.6 g polytetrafluoroethylene powder, 0.6 g hydrophobic nano-silica were added, stirred at 1200 rpm for 60 min, to obtain a step iii mixture;

[0091] (iv) Mix the mixture of step ii with the mixture of step iii, and stir at 1200 rpm for 30 min to obtain the A component.

[0092] (2) Preparation of B component

[0093] (i) Add 10 g of polyethyleneimine SP-003 and 65 g of alicyclic amine curing agent Ancamine 2280, and stir at 1200 rpm for 10 min, then add 5 g of bis(3-triethoxysilyl)propylamine, and stir at 1000 rpm for 10 min to obtain the B component.

[0094] (3) Mix the A component and the B component in a mass ratio of 5:1.

[0095] Comparative Example 4

[0096] A method for preparing a coating, comprising the following steps:

[0097] (1) Preparation of A component

[0098] (i) Add 20 g of EPALLOY 8240 phenolic epoxy resin, 20 g of NPEF 170 bisphenol F epoxy resin, 6 g of pentaerythritol glycidyl ether, and 6 g of trimethylol ethane triglycidyl ether, and stir at 1200 rpm for 15 min, then add 0.8 g of SIVO 240 anti-corrosion viscosity reducer, 1 g of BYK-1799 silicone defoaming agent, and 1 g of polyamide wax Opitma, and stir at 1800 rpm for 30 min to obtain a step i mixture;

[0099] (ii) Add 10 g of titanium white powder R-258, 0.5 g of special black 6 carbon black, 6 g of mica powder, 6 g of silicon powder, and 6 g of feldspar powder to the step i mixture, and stir at 1800 rpm for 30 min to obtain a step ii mixture;

[0100] (iii) Add 10 g of C12-14 alkyl glycidyl ether and 1.5 g of BYK 2155 solvent-free hyperdispersant, and stir at 700 rpm for 15 min, then add 0.6 g of polytetrafluoroethylene powder and 0.6 g of hydrophobic nano-silicon dioxide, and stir at 1200 rpm for 60 min to obtain a step iii mixture;

[0101] (iv) Mix the mixture of step ii with the mixture of step iii, and stir at 1200 rpm for 30 min to obtain the A component.

[0102] (2) Preparation of B component

[0103] (i) 65 g of alicyclic amine curing agent Ancamine 2280, 10 g of trimethylhexamethylene diamine were added, stirred at 1200 rpm for 10 min, and then 5 g of bis(3-triethoxysilyl)propylamine was added, stirred at 1000 rpm for 10 min to obtain the B component.

[0104] (3) The A component and the B component were mixed in a mass ratio of 6:1.

[0105] Performance detection

[0106] The high-pressure salt water immersion resistance and the cathodic disbondment resistance of the deep-sea pressure-resistant self-laminating solvent-free coating prepared by the scheme of the present application (Examples 1-3) and Comparative Examples 1-4 were detected. The substrate was a 3 mm sandblasted steel plate, the deep-sea pressure-resistant self-laminating solvent-free coating was sprayed, the design film thickness was 400 μm, after drying and curing at room temperature for 7 days, the sample plate was edge-protected, and then the high-pressure salt water immersion resistance test was performed according to the standard “NACE TM0185-2024 Evaluation of the Corrosion Protection of Plastic Coatings Inside Pipes by Autoclave Testing”; at the same time, considering that the organic coating used in the deep-sea environment is generally used in combination with cathodic protection, the cathodic disbondment resistance test of the deep-sea pressure-resistant self-laminating solvent-free coating was performed according to the B method in “ISO 15711-2003 Paints and Varnishes Determination of the Resistance of Coatings Exposed to Seawater to Cathodic Disbondment”, after the test, the coating was peeled off, the peeling radius was measured, and the results are shown in Table 1 below.

[0107] Table 1 Test results of deep-sea pressure-resistant self-laminating solvent-free coating for high-pressure salt water immersion resistance and cathodic disbondment resistance

[0108]

[0109]

[0110] As can be seen from Table 1, under the 20 MPa, 3.5% NaCl high-pressure immersion test conditions, the deep-sea pressure-resistant self-layering solvent-free coatings prepared in Examples 1-3 are tested for 90 days, and the coatings are intact without failure problems such as blistering, cracking and peeling; while Comparative Examples 1-4 all have blistering and rusting after 60 days of testing, and the coatings fail; at the same time, through the cathodic disbonding test, it can be seen that the deep-sea pressure-resistant self-layering solvent-free coatings of the present application have a smaller disbonding radius than Comparative Examples 1-4, and thus have excellent cathodic disbonding resistance and good compatibility with cathodic protection. The excellent performance of Examples 1-3 is mainly due to the use of self-layering design concept, in which the polar and high-surface-tension glycidyl ether and organic amine migrate to the "coating-substrate" interface during the curing process of the solvent-free coating, and the wet adhesion is improved through the adsorption of polar groups; at the same time, the glycidyl ether and organic amine with low polarity and surface tension and the polytetrafluoroethylene powder and nano-silicon dioxide with hydrophobic function migrate to the surface of the coating, greatly improving the hydrophobicity of the paint film, reducing the diffusion and transmission of moisture in the paint film, and improving the shielding effect of the paint film. Therefore, through the self-layering effect, the technical problem of high polarity and hydrophobicity of organic coatings used in deep-sea high-pressure conditions cannot be simultaneously considered is solved. In summary, the deep-sea pressure-resistant self-layering solvent-free coating of the present application has excellent wet adhesion and hydrophobic shielding properties, and meets the high-pressure immersion corrosion resistance requirements in the deep-sea field.

[0111] The embodiments of the specific implementation are the preferred embodiments of the present application, and do not limit the protection scope of the present application, so that: any equivalent changes made according to the structure, shape, principle of the present application should be covered within the protection scope of the present application.

Claims

1. A deep-sea pressure-resistant, self-stratifying, solvent-free coating, characterized in that: It consists of two components, A and B, with a weight ratio of (4~6):1 between components A and B. Component A comprises the following components by weight: 30-40 parts epoxy resin; 10-15 parts type A reactive diluent; 10-15 parts type B reactive diluent; 1-1.5 parts solvent-free superdispersant; 0.5-1.5 parts preservative and viscosity reducer; 0.5-1 part silicone defoamer; 0.5-1 part polyamide wax thixotropic agent; 0.5-1 part polytetrafluoroethylene powder; 0.5-1 part hydrophobic nano silica; 10-20 parts pigment; and 10-20 parts filler. The type A reactive diluent is selected from one or a combination of two of trifunctional glycidyl ethers and tetrafunctional glycidyl ethers; the type B reactive diluent is selected from one or a combination of two of monofunctional glycidyl ethers containing eight or more long carbon chains. Component B comprises the following components by weight: 50-70 parts of alicyclic amine curing agent; 5-10 parts of polyethyleneimine; 5-10 parts of long-chain aliphatic amine; 3-5 parts of adhesion promoter; the long-chain aliphatic amine is selected from one or more aliphatic diamines containing 6-9 C atoms in a long carbon chain.

2. The deep-sea pressure-resistant self-stratifying solvent-free coating according to claim 1, characterized in that: In component A, the epoxy resin is selected from any one or a combination of two of bisphenol F epoxy resin and phenolic epoxy resin; the functionality of the epoxy resin is 2.1-2.

4.

3. The deep-sea pressure-resistant self-stratifying solvent-free coating according to claim 1, characterized in that: In component A, the corrosion inhibitor and viscosity reducer is a functional silane dispersant.

4. The deep-sea pressure-resistant self-stratifying solvent-free coating according to claim 1, characterized in that: In component B, the alicyclic amine curing agent is selected from any one or a combination of two or more of 1,3-cyclohexanedimethylamine, cyclohexanediamine, isophoronediamine, and 4,4'-diaminodicyclohexylmethane.

5. The deep-sea pressure-resistant self-stratifying solvent-free coating according to claim 1, characterized in that: In component B, the polyethyleneimine is selected from any one or more of the polyethyleneimines with a molecular weight between 300 and 600.

6. The deep-sea pressure-resistant self-stratifying solvent-free coating according to claim 1, characterized in that: In component B, the adhesion promoter is selected from either bis(3-triethoxysilyl)propylamine or bis(3-trimethoxysilyl)propylamine, or a combination of two of them.

7. A method for preparing a deep-sea pressure-resistant self-stratifying solvent-free coating according to any one of claims 1-6, characterized in that: Includes the following steps: Preparation of component S1.A i. Mix epoxy resin and type A reactive diluent, stir and disperse evenly at 800-1200 rpm, then add anti-corrosion and viscosity reducer, silicone defoamer and polyamide wax thixotropic agent, stir and disperse evenly at 1200-18000 rpm to obtain mixture i. ii. Add pigments and fillers to mixture i, and stir and disperse evenly at 1200-18000 rpm. During the dispersion process, control the temperature at 55-60℃ and the fineness at less than 80μm to obtain mixture ii; iii. Add solvent-free superdispersant to type B reactive diluent, stir and disperse evenly at 600-800 rpm, then add polytetrafluoroethylene powder and hydrophobic nano silica, stir and disperse evenly at 1200-2000 rpm to obtain mixture iii; iv. Mix mixture ii and mixture iii, and stir at 800-1200 rpm to disperse evenly, to obtain component A; Preparation of S2.B component Mix the alicyclic amine curing agent, polyethyleneimine, and long-chain aliphatic amine, and stir at 800-1200 rpm to disperse evenly. Then add the adhesion promoter and stir at 600-1000 rpm to disperse evenly to obtain component B. S3. When using, mix component A and component B at a ratio of (4~6):1.

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