An anti-corrosion low-viscosity solvent-free coating for oil well pipes, its preparation method and application

Abstract

The present invention provides a kind of anti-corrosion low-viscosity solvent-free coating for oil well pipes and its preparation method and application, which belongs to the technical field of coatings. The raw materials for preparing the coating include component A and component B; by mass fraction, the component A includes the following raw materials: phenolic epoxy resin, epoxy reactive diluent, adhesion promoter, filler, leveling agent, dispersant, defoamer, anti-settling agent; the component B includes phthalic anhydride modified polyphenyl ring aromatic amine curing agent; the viscosity of the anti-corrosion low-viscosity solvent-free coating for oil well pipes is 100.1-118.6KU. The coating formed by the coating has high coating hardness, heat resistance and permeability resistance, and meets the high temperature and high pressure autoclave performance requirements in the SY / T6717-2016 standard; the coating has low viscosity and can be sprayed internally without heating using ordinary single-component spraying equipment, which can solve the problem of coating construction inside small-diameter oil well pipes with a pipe diameter of less than 89mm.

Description

Technical Field

[0001] The invention relates to the technical field of coatings, and in particular to an anti-corrosion low-viscosity solvent-free coating for oil well pipes, a preparation method and application thereof. Background Art

[0002] The industrial development of countries around the world has led to an increasing demand for oil and a growing dependence on the oil industry. The development of the oil industry is inseparable from the supporting facilities of the entire process of oil field exploitation. In the process of crude oil exploitation, the oil well produced contains a variety of complex corrosive media, such as hydrogen sulfide, carbon dioxide, dissolved oxygen, etc., which cause serious corrosion of the downhole oil pipe. At the same time, the working environment safety, corrosion, wax deposition, scaling and other problems of oil well pipes have become more prominent.

[0003] Traditional solvent-free coatings have high viscosity and need to be heated and applied using a high-pressure airless spraying machine with a double-tube feed, which brings inconvenience to the construction. Oil well pipes with a diameter less than 89mm cannot even be processed. Moreover, the coatings formed by existing solvent-free coatings lack the performance in hardness, heat resistance and anti-penetration. Summary of the invention

[0004] The purpose of the present invention is to provide an anti-corrosion low-viscosity solvent-free coating for the inside of an oil well pipe, and a preparation method and application thereof. The coating provided by the present invention is an environmentally friendly coating with low viscosity. It can be sprayed inside using an ordinary single-component spraying machine without heating, and can solve the problem of coating construction inside small-diameter oil well pipes with a diameter of less than 89 mm. At the same time, it has high hardness, heat resistance and permeability resistance, and meets the high-temperature and high-pressure autoclave performance requirements in the SY / T6717-2016 standard.

[0005] In order to achieve the above-mentioned object of the invention, the present invention provides the following technical solutions:

[0006] The present invention provides an anti-corrosion low-viscosity solvent-free coating for oil well pipes, the raw materials for preparing the coating include component A and component B;

[0007] Calculated by weight, the component A includes the following raw materials: 20-50 parts of phenolic epoxy resin, 0-15 parts of epoxy reactive diluent, 5-15 parts of adhesion promoter, 20-40 parts of filler, 0.3-0.5 parts of leveling agent, 0.2-0.5 parts of dispersant, 0.2-0.5 parts of defoamer, and 0.2-0.5 parts of anti-settling agent;

[0008] The component B includes a phthalic anhydride-modified polyphenyl aromatic amine curing agent;

[0009] The mass ratio of component A to component B is (6-8):1;

[0010] The viscosity of the anti-corrosion low-viscosity solvent-free coating for oil well pipes is 100.1 to 118.6 KU.

[0011] Preferably, the phenolic epoxy resin is DEN-431 phenolic epoxy resin and / or NPPN-631 phenolic epoxy resin.

[0012] Preferably, the epoxy active diluent is a glycidyl ether diluent; the glycidyl ether diluent is AGE748 diluent and / or HS622 diluent.

[0013] Preferably, the adhesion promoter is HY-F4011 adhesion promoter and / or Momentive A-187 adhesion promoter.

[0014] Preferably, the filler includes one or more of glass powder, precipitated barium sulfate, talc powder, and carbon black.

[0015] Preferably, the leveling agent includes one or more of BYK-358N leveling agent, BYK-350 leveling agent, and BYK354 leveling agent.

[0016] Preferably, the dispersant includes one or more of ANTI-TERRA-U dispersant, BYK-110 dispersant, and HY-9010 dispersant.

[0017] Preferably, the anti-settling agent includes one or more of CARH-HD810 anti-settling agent, Clayminton 72 anti-settling agent, and M-5 anti-settling agent.

[0018] The present invention also provides a preparation method of the anti-corrosion low-viscosity solvent-free coating for oil well pipes described in the above technical solution, including the following steps:

[0019] Mix the phenolic epoxy resin, epoxy active diluent, adhesion promoter, filler, leveling agent, dispersant, defoaming agent, and anti-settling agent to obtain component A;

[0020] Mix component A with a trimellitic anhydride-modified polycyclic aromatic amine curing agent to obtain the anti-corrosion low-viscosity solvent-free coating for oil well pipes.

[0021] The present invention also provides the application of the anti-corrosion low-viscosity solvent-free coating for oil well pipes described in the above technical solution or the anti-corrosion low-viscosity solvent-free coating for oil well pipes prepared by the preparation method described in the above technical solution in oil well pipes.

[0022] The present invention provides an anti-corrosion low-viscosity solvent-free coating for the inner part of oil well pipes, which is characterized in that its preparation raw materials include component A and component B; by mass parts, the component A includes the following preparation raw materials: 20-50 parts of phenolic epoxy resin, 0-15 parts of epoxy active diluent, 5-15 parts of adhesion promoter, 20-40 parts of filler, 0.3-0.5 parts of leveling agent, 0.2-0.5 parts of dispersant, 0.2-0.5 parts of defoaming agent, 0.2-0.5 parts of anti-settling agent; the component B includes a trimellitic anhydride-modified polycyclic aromatic amine curing agent; the mass ratio of the component A to the component B is (6-8):1; the viscosity of the anti-corrosion low-viscosity solvent-free coating for the inner part of oil well pipes is 100.1-118.6 KU. The anti-corrosion low-viscosity solvent-free coating for the inner part of oil well pipes provided by the present invention adopts a film-forming system of phenolic epoxy resin and trimellitic anhydride-modified polycyclic aromatic amine curing agent. The aromatic amine contains multiple stable benzene rings, and the amino group is connected to the benzene ring. At the same time, the trimellitic anhydride skeleton introduced in the structure, the hydroxyl group on the main chain of phenolic epoxy resin reacts with the carboxyl group of the acid anhydride to form a stable cyclic acid anhydride, generating a three-dimensional network structure polymer. The polycyclic benzene rings and the introduced acid anhydride skeleton make the cured product have high coating hardness, heat resistance and anti-permeability, solve the problem of anti-corrosion of the inner coating of oil well pipes resistant to H2S and CO2 corrosion, and meet the performance requirements of high temperature and high pressure autoclave in SY / T6717-2016 standard. The viscosity of traditional solvent-free coatings is high, reaching 120 KU (50 °C), and two-component airless spraying is required after heating. The coating provided by the present invention has low viscosity, and ordinary single-component spraying equipment can be used for inner spraying operation without heating, which can solve the problem of inner coating construction of small-diameter oil well pipes with a diameter less than 89 mm. Detailed embodiments

[0023] The present invention provides an anti-corrosion low-viscosity solvent-free coating for the inner part of oil well pipes, and its preparation raw materials include component A and component B;

[0024] By mass parts, the component A includes the following preparation raw materials: 20-50 parts of phenolic epoxy resin, 0-15 parts of epoxy active diluent, 5-15 parts of adhesion promoter, 20-40 parts of filler, 0.3-0.5 parts of leveling agent, 0.2-0.5 parts of dispersant, 0.2-0.5 parts of defoaming agent, 0.2-0.5 parts of anti-settling agent;

[0025] The component B includes a trimellitic anhydride-modified polycyclic aromatic amine curing agent;

[0026] The mass ratio of the component A to the component B is (6-8):1;

[0027] The viscosity of the anti-corrosion low-viscosity solvent-free coating for the inner part of oil well pipes is 100.1-118.6 KU.

[0028] Unless otherwise specified, the present invention has no special requirements for the sources of the raw materials used, and commercially available products well-known to those skilled in the art can be used.

[0029] The raw materials for preparing the anti-corrosion low-viscosity solvent-free coating inside oil well pipes provided by the present invention include Component A.

[0030] In the present invention, the Component A includes: 20 - 50 parts of phenolic epoxy resin, preferably 40 - 50 parts. In the present invention, the phenolic epoxy resin is preferably DEN-431 phenolic epoxy resin and / or NPPN-631 phenolic epoxy resin, more preferably DEN-431 phenolic epoxy resin; the viscosity of the phenolic epoxy resin is 1100 - 1700 cps at 25°C; the NPPN-631 phenolic epoxy resin is a phenol-type phenolic epoxy resin, with an epoxy equivalent of 168 - 178 g / eq and a viscosity of 1100 - 1700 cps at 52°C; the DEN-431 phenolic epoxy resin has an epoxy equivalent of 172 - 179 g / eq, a viscosity of 1100 - 1700 cps at 25°C, and a functionality of 2.8.

[0031] Based on 1 part by mass of phenolic epoxy resin, the Component A includes: 0 - 15 parts of epoxy active diluent, preferably 10 - 15 parts. In the present invention, the epoxy active diluent is preferably a glycidyl ether diluent; the glycidyl ether diluent is preferably AGE748 diluent and / or HS622 diluent, more preferably AGE748 diluent or HS622 diluent; the viscosity of the AGE748 diluent is 3 - 12 mPa·s at 25°C, and the epoxy value is 0.34 - 0.37 eq / 100 g; the viscosity of the HS622 diluent is 10 - 20 mPa·s at 25°C, and the epoxy value is 0.74 - 0.82 eq / 100 g.

[0032] Based on 1 part by mass of phenolic epoxy resin, the Component A includes: 5 - 15 parts of adhesion promoter, preferably 10 - 15 parts. In the present invention, the adhesion promoter is HY-F4011 adhesion promoter and / or Momentive A-187 adhesion promoter, more preferably Momentive A-187 adhesion promoter.

[0033] Based on 1 part by mass of phenolic epoxy resin, the Component A includes: 20 - 40 parts of filler, preferably 25 - 40 parts. In the present invention, the filler preferably includes one or more of glass powder, precipitated barium sulfate, talc powder, and carbon black, more preferably glass powder, precipitated barium sulfate, talc powder, and carbon black; the glass powder is preferably 1250-mesh glass powder; the precipitated barium sulfate is preferably 800-mesh precipitated barium sulfate; the talc powder is preferably 800-mesh talc powder.

[0034] The 1250-mesh glass powder used in the present invention has good anti-settling effect, small particle size, Mohs hardness of 7.8, and good scratch resistance. The precipitated barium sulfate used has the characteristics of strong chemical inertness, good stability, acid resistance, alkali resistance, water resistance, and moderate hardness. At the same time, it can also improve the stiffness, viscosity, and wear resistance of the product. The talc powder used is rich in components such as calcium silicate and magnesium aluminum silicate. These components can make the coating harden more evenly, improve the quality of the coating, increase the scratch resistance of the coating. At the same time, the talc powder also has good processability and water resistance.

[0035] In the present invention, the mass ratio of the glass powder, precipitated barium sulfate, talc powder, and carbon black is preferably (5-15):(5-15):(5-15):0.2, more preferably (8-15):(5-10):(10-15):0.2.

[0036] Based on 1 part by mass of phenolic epoxy resin, the component A includes: 0.3-0.5 parts of a leveling agent, preferably 0.3-0.4 parts. In the present invention, the leveling agent preferably includes one or more of BYK-358N leveling agent, BYK-350 leveling agent, and BYK354 leveling agent, more preferably BYK-350 leveling agent. The leveling agent used in the present invention can significantly improve the leveling property of the coating and increase the gloss, prevent cratering, and produce a long-wave effect, slightly reducing the surface tension of the coating, but not affecting the recoatability and interlayer adhesion of the coating.

[0037] Based on 1 part by mass of phenolic epoxy resin, the component A includes: 0.2-0.5 parts of a dispersant, preferably 0.3-0.5 parts. In the present invention, the dispersant preferably includes one or more of ANTI-TERRA-U dispersant, BYK-110 dispersant, and HY-9010 dispersant, more preferably BYK-110 dispersant. The function of the dispersant used in the present invention is to reduce the time and energy required to complete the dispersion process, stabilize the dispersed pigment dispersion, modify the surface properties of the pigment particles, adjust the motility of the pigment particles, etc., and prevent flocculation and back coarsening.

[0038] Based on 1 part by mass of phenolic epoxy resin, the component A includes: 0.2-0.5 parts of an antifoaming agent, preferably 0.4-0.5 parts. In the present invention, the antifoaming agent preferably includes one or more of 6800 antifoaming agent, A530 antifoaming agent, and Desmodur44V20 antifoaming agent, more preferably 6800 antifoaming agent. The main function of the antifoaming agent used in the present invention is to reduce the surface tension of the foaming liquid, change the surface pressure of the bubbles, and promote the rupture of the bubbles and the dissipation of the foam. The unique chemical properties of the antifoaming agent can also quickly react with the foaming system, quickly suppress foaming, and prevent the re-generation of bubbles.

[0039] Based on 1 part by mass of phenolic epoxy resin, the component A includes: 0.2 - 0.5 parts of anti-settling agent, preferably 0.3 - 0.5 parts. In the present invention, the anti-settling agent preferably includes one or more of CARH-HD810 anti-settling agent, Clayminton 72 anti-settling agent and M-5 anti-settling agent, more preferably CARH-HD810 anti-settling agent. The addition of the anti-settling agent in the coating of the present invention is to prevent the precipitation of pigments and fillers due to gravity, which may cause color difference or even unevenness in the coating, thereby affecting the service life of the coating.

[0040] The raw materials for preparing the anti-corrosion low-viscosity solvent-free coating for the inner part of oil well pipes provided by the present invention include component B.

[0041] In the present invention, the component B includes: phthalic anhydride-modified polycyclic aromatic amine curing agent.

[0042] In the present invention, the preparation method of the phthalic anhydride-modified polycyclic aromatic amine curing agent is preferably:

[0043] Mix phthalic anhydride and polycyclic aromatic amine, carry out a pre-nucleophilic addition reaction, and after mixing the obtained pre-nucleophilic addition reaction product with a promoter, carry out a nucleophilic addition reaction to obtain a phthalic anhydride-modified polycyclic aromatic amine curing agent.

[0044] In the present invention, the mass ratio of phthalic anhydride to polycyclic aromatic amine is preferably 3:7; the temperature of the pre-nucleophilic addition reaction is preferably 120 - 124 °C, more preferably 124 °C, and the heat preservation time is preferably 2 h; the promoter is preferably 2,4,6-tris(dimethylaminomethyl)phenol (DMP-30); the mass of the promoter is preferably 2% of the total mass of phthalic anhydride and polycyclic aromatic amine; the mixing is preferably carried out under stirring; the stirring rate is preferably 200 - 500 rpm, more preferably 300 - 400 rpm; the stirring time is preferably 30 min; the temperature of the nucleophilic addition reaction is preferably 65 °C, and the heat preservation time is preferably 2 h. After the nucleophilic addition reaction is completed, the present invention preferably further includes cooling the nucleophilic addition reaction product to room temperature for discharging; the cooling is preferably natural cooling to room temperature.

[0045] Nucleophilic addition reaction occurs between the carbonyl carbon atom of phthalic anhydride and the nitrogen atom of polycyclic aromatic amine.

[0046] In the present invention, the mass ratio of component A to component B is preferably (6 - 8):1, more preferably 7:1.

[0047] In the present invention, the viscosity of the anti-corrosion low-viscosity solvent-free coating for the inner part of oil well pipes is 100.1 - 118.6 KU, preferably 101 - 115 KU.

[0048] The anti-corrosion low-viscosity solvent-free coating for the inside of oil well pipes provided by the present invention adopts a film-forming system of phenolic epoxy resin and trimellitic anhydride-modified polycyclic aromatic amine curing agent. The aromatic amine contains multiple stable benzene rings, and the amino group is connected to the benzene ring. At the same time, the trimellitic anhydride skeleton introduced in the structure, and the hydroxyl group on the main chain of the epoxy resin undergoes a condensation reaction with the carboxyl group of the acid anhydride to form a stable cyclic acid anhydride, generating a three-dimensional network structure polymer, making the cured product have high coating hardness, heat resistance and anti-permeability, solving the problem of anti-corrosion of the inner coating of oil well pipes against H2S and CO2 corrosion, and meeting the performance requirements of high temperature and high pressure autoclave in SY / T6717-2016 standard; this coating has low viscosity and can be internally sprayed by ordinary single-component spraying tools without heating, which can solve the problem of internal coating construction of small-diameter oil well pipes with a diameter less than 89mm.

[0049] The performance requirements of high temperature and high pressure autoclave are as follows: Performance requirements of acidic autoclave: Liquid phase: water, toluene and kerosene (mixed in equal volume ratio) Temperature: 107°C, Pressure: 35MPa, Time: 16h, CO2 pressurization. After the test, the coating has no blisters and the adhesion does not degrade; Performance requirements of alkaline autoclave: Liquid phase: NaOHaq., PH = 12.5 Temperature: 148°C, Pressure: 70MPa, Time: 16h, N2 pressurization. After the test, the coating has no blisters and the adhesion does not degrade.

[0050] The present invention also provides a preparation method of the anti-corrosion low-viscosity solvent-free coating for the inside of oil well pipes described in the above technical solution, including the following steps:

[0051] Mix phenolic epoxy resin, epoxy active diluent, adhesion promoter, filler, leveling agent, dispersant, defoamer and anti-settling agent to obtain component A;

[0052] Mix the component A with trimellitic anhydride-modified polycyclic aromatic amine curing agent to obtain the anti-corrosion low-viscosity solvent-free coating for the inside of oil well pipes.

[0053] The present invention has no special limitation on the mixing, and it is only necessary to mix the raw materials evenly.

[0054] The present invention also provides the application of the anti-corrosion low-viscosity solvent-free coating for the inside of oil well pipes described in the above technical solution or the anti-corrosion low-viscosity solvent-free coating for the inside of oil well pipes prepared by the preparation method described in the above technical solution in oil well pipes.

[0055] The present invention has no special limitation on the application of the anti-corrosion low-viscosity solvent-free coating for the inside of oil well pipes in oil well pipes, and the well-known application methods in the art can be adopted.

[0056] In the present invention, the preferred application method of the anti-corrosion low-viscosity solvent-free coating for oil well pipes in the oil well pipes is as follows: spraying the anti-corrosion low-viscosity solvent-free coating for oil well pipes on the inner wall of the oil well pipes, and curing to obtain the oil well pipes with an inner anti-corrosion coating; the preferred curing temperature is 180 °C; the preferred curing time is 2 h.

[0057] Next, the technical solutions in the present invention will be clearly and completely described in conjunction with the embodiments in the present invention, but they cannot be understood as limiting the protection scope of the present invention.

[0058] Example 1

[0059] By mass, the raw materials for preparing the anti-corrosion low-viscosity solvent-free coating for oil well pipes in this example are as follows:

[0060] Component A: 50 parts of phenolic epoxy resin (DEN-431 phenolic epoxy resin), 10 parts of epoxy active diluent (HS622 diluent), 10 parts of adhesion promoter (Momentive A-187 adhesion promoter), 10 parts of glass powder (1250 mesh), 10 parts of barium sulfate (800 mesh), 10 parts of talc powder (800 mesh), 0.2 part of carbon black, 0.3 part of leveling agent (BYK-350 leveling agent), 0.3 part of dispersant (BYK-110 dispersant), 0.3 part of defoaming agent (6800 defoaming agent), 0.2 part of anti-settling agent (CARH-HD810 anti-settling agent);

[0061] Component B: Trimellitic anhydride modified polycyclic aromatic amine curing agent, and the preparation method is as follows: adding trimellitic anhydride (CAS: 552-30-7) and polycyclic aromatic amine (H-113B) into the reactor in a mass ratio of 3:7, heating to 124 °C, carrying out a pre-nucleophilic addition reaction for 2 h, then adding 2% of accelerator DMP-30 based on the total mass of trimellitic anhydride and polycyclic aromatic amine, stirring at 400 rpm for 30 min, carrying out a nucleophilic addition reaction at 65 °C for 2 h, and then naturally cooling to room temperature and discharging;

[0062] Mix components A and B in a mass ratio of 7:1 to obtain the anti-corrosion low-viscosity solvent-free coating for oil well pipes.

[0063] Example 2

[0064] By mass, the raw materials for preparing the anti-corrosion low-viscosity solvent-free coating for oil well pipes in this example are as follows:

[0065] Component A: 40 parts of phenolic epoxy resin (DEN-431 phenolic epoxy resin), 15 parts of epoxy active diluent (HS622 diluent), 10 parts of adhesion promoter (Momentive A-187 adhesion promoter), 5 parts of glass powder (1250 mesh), 15 parts of barium sulfate (800 mesh), 8 parts of talc powder (800 mesh), 0.2 parts of carbon black, 0.3 parts of leveling agent (BYK-350 leveling agent), 0.3 parts of dispersant (BYK-110 dispersant), 0.2 parts of defoamer (6800 defoamer), 0.5 parts of anti-settling agent (CARH-HD810 anti-settling agent);

[0066] Component B: Trimellitic anhydride modified polycyclic aromatic amine curing agent. Preparation method: Add trimellitic anhydride (CAS: 552-30-7) and polycyclic aromatic amine (H-113B) into the reactor in a mass ratio of 3:7, heat up to 124 °C, carry out pre-nucleophilic addition reaction for 2 h, then add 2% of accelerator DMP-30 based on the total mass of trimellitic anhydride and polycyclic aromatic amine, stir at 400 rpm for 30 min, carry out nucleophilic addition reaction at 65 °C for 2 h, and then let it cool naturally to room temperature and discharge;

[0067] Mix Component A and Component B in a mass ratio of 7:1 to obtain an anti-corrosion low-viscosity solvent-free coating for the inner part of oil well pipes.

[0068] Example 3

[0069] By mass fraction, the raw materials for preparing the anti-corrosion low-viscosity solvent-free coating for the inner part of oil well pipes in this example are as follows:

[0070] Component A: 50 parts of phenolic epoxy resin (DEN-431 phenolic epoxy resin), 15 parts of epoxy active diluent (AGE748 diluent), 15 parts of adhesion promoter (Momentive A-187 adhesion promoter), 8 parts of glass powder (1250 mesh), 5 parts of barium sulfate (800 mesh), 15 parts of talc powder (800 mesh), 0.2 parts of carbon black, 0.5 parts of leveling agent (BYK-350 leveling agent), 0.3 parts of dispersant (BYK-110 dispersant), 0.5 parts of defoamer (6800 defoamer), 0.4 parts of anti-settling agent (CARH-HD810 anti-settling agent);

[0071] Component B: Trimellitic anhydride modified polycyclic aromatic amine curing agent. Preparation method: Add trimellitic anhydride (CAS: 552-30-7) and polycyclic aromatic amine (H-113B) into the reactor in a mass ratio of 3:7, heat up to 124 °C, carry out pre-nucleophilic addition reaction for 2 h, then add 2% of accelerator DMP-30 based on the total mass of trimellitic anhydride and polycyclic aromatic amine, stir at 400 rpm for 30 min, carry out nucleophilic addition reaction at 65 °C for 2 h, and then let it cool naturally to room temperature and discharge;

[0072] Mix component A and component B in a mass ratio of 7:1 to obtain a low-viscosity solvent-free anti-corrosion coating for oil well pipes.

[0073] Example 4

[0074] By mass, the raw materials for preparing the low-viscosity solvent-free anti-corrosion coating for oil well pipes in this example are as follows:

[0075] Component A: 50 parts of phenolic epoxy resin (NPPN-631 phenolic epoxy resin), 15 parts of epoxy active diluent (AGE748 diluent), 15 parts of adhesion promoter (Momentive A-187 adhesion promoter), 15 parts of glass powder (1250 mesh), 5 parts of barium sulfate (800 mesh), 10 parts of talc powder (800 mesh), 0.2 part of carbon black, 0.5 part of leveling agent (BYK-350 leveling agent), 0.5 part of dispersant (BYK-110 dispersant), 0.4 part of defoaming agent (6800 defoaming agent), 0.3 part of anti-settling agent (CARH-HD810 anti-settling agent);

[0076] Component B: Trimellitic anhydride modified polycyclic aromatic amine curing agent. Preparation method: Add trimellitic anhydride (CAS: 552-30-7) and polycyclic aromatic amine (H-113B) to the reactor in a mass ratio of 3:7, heat up to 124 °C, carry out a pre-nucleophilic addition reaction for 2 h, then add 2% of accelerator DMP-30 based on the total mass of trimellitic anhydride and polycyclic aromatic amine, stir at 400 rpm for 30 min, carry out a nucleophilic addition reaction at 65 °C for 2 h, and then naturally cool to room temperature and discharge;

[0077] Mix component A and component B in a mass ratio of 7:1 to obtain a low-viscosity solvent-free anti-corrosion coating for oil well pipes.

[0078] Example 5

[0079] By mass, the raw materials for preparing the low-viscosity solvent-free anti-corrosion coating for oil well pipes in this example are as follows:

[0080] Component A: 40 parts of phenolic epoxy resin (NPPN-631 phenolic epoxy resin), 15 parts of epoxy active diluent (AGE748 diluent), 10 parts of adhesion promoter (Momentive A-187 adhesion promoter), 6 parts of glass powder (1250 mesh), 15 parts of barium sulfate (800 mesh), 8 parts of talc powder (800 mesh), 0.2 part of carbon black, 0.4 part of leveling agent (BYK-350 leveling agent), 0.2 part of dispersant (BYK-110 dispersant), 0.3 part of defoaming agent (6800 defoaming agent), 0.4 part of anti-settling agent (CARH-HD810 anti-settling agent);

[0081] Component B: Trimellitic anhydride modified polycyclic aromatic amine curing agent, the preparation method is as follows: Add trimellitic anhydride (CAS: 552-30-7) and polycyclic aromatic amine (H-113B) into the reactor at a mass ratio of 3:7, heat up to 124 °C, carry out a pre-nucleophilic addition reaction for 2 h, then add accelerator DMP-30 which is 2% of the total mass of trimellitic anhydride and polycyclic aromatic amine, stir at 400 rpm for 30 min, carry out a nucleophilic addition reaction at 65 °C for 2 h, and then cool naturally to room temperature and discharge;

[0082] Mix Component A and B according to a mass ratio of 7:1 to obtain an anti-corrosion low-viscosity solventless coating for oil well pipes.

[0083] Example 6

[0084] By mass, the raw materials for preparing the anti-corrosion low-viscosity solventless coating for oil well pipes in this example are as follows:

[0085] Component A: 30 parts of phenolic epoxy resin (NPPN-631 phenolic epoxy resin), 15 parts of epoxy active diluent (AGE748 diluent), 8 parts of adhesion promoter (Momentive A-187 adhesion promoter), 10 parts of glass powder (1250 mesh), 10 parts of barium sulfate (800 mesh), 5 parts of talc powder (800 mesh), 0.2 part of carbon black, 0.4 part of leveling agent (BYK-350 leveling agent), 0.3 part of dispersant (BYK-110 dispersant), 0.3 part of defoamer (6800 defoamer), 0.5 part of anti-settling agent (CARH-HD810 anti-settling agent);

[0086] Component B: Trimellitic anhydride modified polycyclic aromatic amine curing agent, the preparation method is as follows: Add trimellitic anhydride (CAS: 552-30-7) and polycyclic aromatic amine (H-113B) into the reactor at a mass ratio of 3:7, heat up to 124 °C, carry out a pre-nucleophilic addition reaction for 2 h, then add accelerator DMP-30 which is 2% of the total mass of trimellitic anhydride and polycyclic aromatic amine, stir at 400 rpm for 30 min, carry out a nucleophilic addition reaction at 65 °C for 2 h, and then cool naturally to room temperature and discharge;

[0087] Mix Component A and B according to a mass ratio of 7:1 to obtain an anti-corrosion low-viscosity solventless coating for oil well pipes.

[0088] Comparative Example 1

[0089] By mass, the raw materials for preparing the anti-corrosion low-viscosity solventless coating for oil well pipes in this comparative example are as follows:

[0090] Component A: 40 parts of phenolic epoxy resin (NPPN-638S phenolic epoxy resin), 20 parts of epoxy active diluent (AGE748 diluent), 3 parts of adhesion promoter (Momentive A-187 adhesion promoter), 10 parts of glass powder (1250 mesh), 10 parts of barium sulfate, 5 parts of talc powder, 0.2 parts of carbon black, 0.4 parts of leveling agent (BYK-350 leveling agent), 0.3 parts of dispersant (BYK-110 leveling agent), 0.3 parts of defoamer (6800 defoamer), 0.5 parts of anti-settling agent (CARH-HD810 anti-settling agent);

[0091] Component B: Trimellitic anhydride modified polycyclic aromatic amine curing agent. Preparation method: Add trimellitic anhydride (CAS: 552-30-7) and polycyclic aromatic amine (H-113B) to the reactor in a mass ratio of 3:7, heat up to 124 °C, carry out a pre-nucleophilic addition reaction for 2 h, then add 2% of accelerator DMP-30 based on the total mass of trimellitic anhydride and polycyclic aromatic amine, stir at 400 rpm for 30 min, carry out a nucleophilic addition reaction at 65 °C for 2 h, and then cool naturally to room temperature and discharge;

[0092] Mix Component A and Component B in a mass ratio of 7:1 to obtain an anti-corrosion low-viscosity solvent-free coating for the inner part of oil well pipes.

[0093] Application Examples 1 - 6

[0094] Spray the anti-corrosion low-viscosity solvent-free coatings for the inner part of oil well pipes obtained in Examples 1 - 6 onto the inner part of oil well pipes respectively, and cure at 180 °C for 2 h to obtain oil well pipes with an inner anti-corrosion coating.

[0095] Comparative Application Example 1

[0096] The difference from Application Example 1 is that the anti-corrosion low-viscosity solvent-free coating for the inner part of oil well pipes in Example 1 is replaced with the anti-corrosion low-viscosity solvent-free coating for the inner part of oil well pipes in Comparative Example 1.

[0097] Performance Test

[0098] Test the performance of the anti-corrosion coatings on the oil well pipes with inner anti-corrosion coatings obtained in Application Examples 1 - 6. The results are shown in Table 1.

[0099] Table 1 Performance Test Results of Coatings Prepared in Application Examples 1 - 6

[0100]

[0101]

[0102] As can be seen from Table 1, the coating formed by the anti-corrosion low-viscosity solvent-free coating for oil well pipes provided by the present invention adopts a phenolic epoxy and anhydride-modified aromatic amine modified curing system, and the glass transition temperature of the coating is higher than 130 °C. Through the tests on the detection items of the coatings of 6 formulations, the coatings have excellent performance in high temperature and high pressure autoclaves with acid and alkali resistance, and also have good wear resistance and chemical resistance. All the test results of the coatings can meet the performance requirements of high temperature and high pressure autoclaves in SY / T6717-2016 standard.

[0103] Although the above embodiments have described the present invention in detail, they are only a part of the embodiments of the present invention rather than all embodiments. People can also obtain other embodiments based on this embodiment without creative efforts, and these embodiments all fall within the protection scope of the present invention.

Claims

1. An anti-corrosion low-viscosity solvent-free coating for oil well pipes, characterized in that, Its preparation raw materials include component A and component B; By mass parts, the component A includes the following preparation raw materials: 20 - 50 parts of phenolic epoxy resin, 10 - 15 parts of epoxy active diluent, 5 - 15 parts of adhesion promoter, 20 - 40 parts of filler, 0.3 - 0.5 parts of leveling agent, 0.2 - 0.5 parts of dispersant, 0.2 - 0.5 parts of defoamer, and 0.2 - 0.5 parts of anti-settling agent; The component B includes a trimellitic anhydride modified polycyclic aromatic amine curing agent; the trimellitic anhydride modified polycyclic aromatic amine curing agent is obtained by mixing trimellitic anhydride and polycyclic aromatic amine to conduct a pre-nucleophilic addition reaction, and then mixing the obtained pre-nucleophilic addition reaction product with a promoter and conducting a nucleophilic addition reaction; The mass ratio of the component A to the component B is (6 - 8):1; The viscosity of the anti-corrosion low-viscosity solvent-free coating for oil well pipes is 100.1 - 118.6 KU; The viscosity of the phenolic epoxy resin is 1100 - 1700 cps at 25 °C; The epoxy active diluent is a glycidyl ether diluent; the glycidyl ether diluent is AGE748 diluent and / or HS622 diluent; The filler is glass powder, precipitated barium sulfate, talc powder and carbon black; the glass powder is 1250-mesh glass powder; the precipitated barium sulfate is 800-mesh precipitated barium sulfate; the talc powder is 800-mesh talc powder; the mass ratio of the glass powder, precipitated barium sulfate, talc powder and carbon black is (5 - 15):(5 - 15):(5 - 15):0.

2.

2. The anti-corrosion low-viscosity solvent-free coating for oil well pipes according to claim 1, characterized in that, The phenolic epoxy resin is DEN-431 phenolic epoxy resin and / or NPPN-631 phenolic epoxy resin.

3. The anti-corrosion low-viscosity solvent-free coating for oil well pipes according to claim 1, characterized in that, The adhesion promoter is HY-F4011 adhesion promoter and / or Momentive A-187 adhesion promoter.

4. The anti-corrosion low-viscosity solvent-free coating for oil well pipes according to claim 1, wherein The leveling agent includes one or more of BYK-358N leveling agent, BYK-350 leveling agent and BYK-354 leveling agent.

5. The anti-corrosion low-viscosity solvent-free coating for oil well pipes according to claim 1, wherein The dispersant includes one or more of ANTI-TERRA-U dispersant, BYK-110 dispersant and HY-9010 dispersant.

6. The anti-corrosion low-viscosity solvent-free coating for oil well tubing according to claim 1, characterized in that, The anti-settling agent includes one or more of CARH-HD810 anti-settling agent, Clayminton 72 anti-settling agent and M-5 anti-settling agent.

7. The preparation method of the anti-corrosion low-viscosity solvent-free coating for oil well pipes according to any one of claims 1 to 6, characterized in that, It includes the following steps: Mix the phenolic epoxy resin, epoxy active diluent, adhesion promoter, filler, leveling agent, dispersant, defoamer and anti-settling agent to obtain component A; Mix the component A with the trimellitic anhydride modified polycyclic aromatic amine curing agent to obtain the anti-corrosion low-viscosity solvent-free coating for oil well pipes.

8. Application of the anti-corrosion low-viscosity solvent-free coating for oil well pipes according to any one of claims 1 - 6 or the anti-corrosion low-viscosity solvent-free coating for oil well pipes prepared by the preparation method according to claim 7 in oil well pipes.

Images