CN114854282A

CN114854282A - Solvent-free in-pipeline drag reduction coating and preparation method thereof

Info

Publication number: CN114854282A
Application number: CN202210542590.5A
Authority: CN
Inventors: 吕魁奇; 孙明志; 张文惠
Original assignee: Harbin Yuyang Jiatai Environmental Protection New Material Co ltd
Current assignee: Harbin Yuyang Jiatai Environmental Protection New Material Co ltd
Priority date: 2022-05-18
Filing date: 2022-05-18
Publication date: 2022-08-05
Anticipated expiration: 2042-05-18
Also published as: CN114854282B

Abstract

The invention relates to a solvent-free drag reduction coating in a pipeline and a preparation method thereof. The non-coating comprises a component A and a component B; the component A comprises 1-10 parts of epoxy resin E44, 15-40 parts of epoxy resin E51, 0.5-4 parts of active diluent, 0.1-0.5 part of defoaming agent, 0.5-1 part of dispersing agent, 0.1-0.5 part of flatting agent, 0.1-0.5 part of anti-shrinkage agent, 5-15 parts of iron oxide red, 5-15 parts of sericite powder, 10-20 parts of superfine barium sulfate, 5-10 parts of talcum powder, 10-15 parts of zinc phosphate, 5-10 parts of modified polytetrafluoroethylene powder and 0.1-1 part of anti-settling agent; the component B comprises alicyclic amine curing agent and polyamide curing agent. According to the invention, two epoxy resins are used as film forming substances, and the paint is cured by using the mixed curing agent, so that the paint film has excellent resistance reduction, water resistance, corrosion resistance and wear resistance; and the paint has low resin content, no solvent, economy and environmental protection.

Description

Solvent-free in-pipeline drag reduction coating and preparation method thereof

Technical Field

The invention belongs to the technical field of new materials, and particularly relates to a solvent-free in-pipeline drag reduction coating and a preparation method thereof.

Background

China is a large natural gas storage country, and natural gas energy accounts for nearly 1/3 of total energy in China. However, natural gas resources are mainly concentrated in southwest parts, coastal continents and open sea, and the utilization rate of natural gas energy is less than 10%. With the increase of the exploration and development of natural gas resources in China, the natural gas industry in China enters a period of accelerated development. In order to reduce the conveying resistance and improve the gas conveying efficiency. Research and development of natural gas pipeline internal coating materials are widely concerned by relevant decision-making departments, scientific research, design, construction and other units in China. The natural gas inner resistance-reducing coating has multiple practical benefits and economic benefits in the use process, for example, the gas transmission quantity can be greatly improved when the pipe diameter is fixed, the pipe diameter can be reduced on the premise that the gas transmission quantity is fixed, steel is saved, the station spacing is increased, the gas compression station is reduced, the power consumption of a compressor is reduced, the pipe cleaning period is prolonged, the pipe cleaning times are reduced, the corrosion of the inner wall of the pipeline can be reduced, the purity of a medium is ensured, and the harm possibly caused by a corrosive medium to the compressor is eliminated.

Epoxy resin is often used as a film-forming material of solvent-free internal drag-reduction coatings due to its advantages of strong adhesion, high hardness, acid and alkali resistance, wear resistance, etc. The film-forming resin in the component A of the existing solvent-free epoxy internal drag reduction coating is generally single epoxy resin E51, which is convenient for construction due to the lower viscosity of the E51 resin. However, due to its high epoxy value, the cured coating has a high crosslinking density and a high brittleness, and the bending resistance of the coating needs to be further improved. In order to improve the bending resistance of the coating, a toughening resin is usually introduced into the E51 resin, but the introduction of the toughening resin generally affects the strength, modulus and heat resistance of the material, so that the improvement of the physical, mechanical and thermal properties of the material is limited. The component B of the existing epoxy resin internal drag reduction coating is generally a polyamide curing agent, because a paint film cured by the polyamide curing agent has good flexibility, but the paint film has long drying time and poor low-temperature curing property, and causes inconvenience to construction. The polytetrafluoroethylene powder is a common pigment filler in the drag reduction coating in the epoxy resin, has good chemical stability and corrosion resistance, has low friction coefficient, and can improve the smoothness of a paint film. At present, in order to further reduce the conveying resistance and improve the gas conveying efficiency, higher requirements are put on the smoothness of a coating material (paint film) in a natural gas pipeline. When the existing common polytetrafluoroethylene powder is used as a pigment filler and added into a solvent-free internal anti-drag coating, the existing common polytetrafluoroethylene powder is easy to float on the surface of a paint film due to poor dispersibility, so that the smoothness of the paint film needs to be further improved.

In addition, the epoxy resin content of the component A in the existing solvent-free type drag reduction coating in the pipeline is generally more than 35%, and the resin content in a part of the formula can even reach 60%. However, too high a resin content increases paint cost and limits the development of solvent-free drag-reducing coatings in pipelines.

In conclusion, there is a great need for a novel solvent-free drag-reducing coating in pipeline and a preparation method thereof.

Disclosure of Invention

The invention provides a solvent-free drag reduction coating in a pipeline and a preparation method thereof, aiming at solving one or more technical problems in the prior art. According to the invention, the mixed resin of epoxy resin E44 and E51 is used as a film forming substance, the proper proportion is adjusted, the toughness of a paint film is ensured, the influence on viscosity is small, meanwhile, the modified polytetrafluoroethylene powder is used as pigment and filler, the smoothness of the paint film is further improved, in addition, an alicyclic amine curing agent and a polyamide curing agent are used for resin curing, the curing speed of the paint film is improved, and the bending resistance of the paint film is maintained.

The invention provides a solvent-free type in-pipeline drag reduction coating in a first aspect, which comprises a component A and a component B; the component A comprises the following components in parts by weight:

1-10 parts of epoxy resin E44, 15-40 parts of epoxy resin E51, 0.5-4.0 parts of active diluent, 0.1-0.5 part of defoaming agent, 0.5-1 part of dispersing agent, 0.1-0.5 part of flatting agent, 0.1-0.5 part of anti-shrinkage agent, 5-15 parts of iron oxide red, 5-15 parts of sericite powder, 10-20 parts of superfine barium sulfate, 5-10 parts of talcum powder, 10-15 parts of zinc phosphate, 5-10 parts of modified polytetrafluoroethylene powder and 0.1-1 part of anti-settling agent;

the component B comprises alicyclic amine curing agent and polyamide curing agent.

Preferably, the preparation of the modified polytetrafluoroethylene powder comprises the following steps:

(a) dissolving naphthalene in tetrahydrofuran, adding metal sodium, and stirring for 1-2 hours under the protection of nitrogen to obtain a modified solution; the mass ratio of the naphthalene to the tetrahydrofuran to the metal sodium is (40-50): (800-1000): (10-15);

(b) adjusting the temperature of the modification liquid to 5-15 ℃, then adding polytetrafluoroethylene powder into the modification liquid with the temperature of 5-15 ℃, stirring and modifying for 5-10min, then separating the modified polytetrafluoroethylene powder from the modification liquid, and then washing and drying to obtain the modified polytetrafluoroethylene powder.

Preferably, in step (b), washing is performed with acetone and water in this order; and/or the particle size of the polytetrafluoroethylene powder is not more than 5 mu m.

Preferably, the mass ratio of the component A to the component B is (4-10): 1; the alicyclic amine curing agent is a low-viscosity alicyclic amine curing agent, and preferably, the alicyclic amine curing agent is one or more of TAC-900 alicyclic amine curing agent, YH-505 alicyclic amine curing agent and PACM alicyclic amine curing agent; the polyamide curing agent is one or more of 400 polyamide curing agent, 650 polyamide curing agent and 651 polyamide curing agent; and/or the mass ratio of the alicyclic amine curing agent to the polyamide curing agent is (0.5-1.5): 1, preferably 1: 1.

Preferably, the reactive diluent is C _12-14 One or more of alkyl glycidyl ether, butyl glycidyl ether, trimethylolpropane triglycidyl ether, phenyl glycidyl ether and 1, 4-butanediol diglycidyl ether, preferably C _12-14 An alkyl glycidyl ether; the defoaming agent is an organic silicon defoaming agent; the dispersant is hydrophilicA high molecular block copolymer of a pigment group; the leveling agent is a polysiloxane compound; the anti-shrinkage agent is an organic silicon anti-shrinkage agent; and/or the anti-settling agent is one or more of organic bentonite, gas-phase white carbon black and polyolefin wax.

Preferably, the iron oxide red is modified iron oxide red, and the sericite powder is modified sericite powder; and/or the component A also comprises 5-15 parts of modified glass beads.

Preferably, the preparation of the modified iron oxide red or the modified sericite powder or the modified glass beads comprises the following steps:

(i) adding iron oxide red or sericite powder or glass beads into a sodium hydroxide solution, stirring, and performing post-treatment to obtain pretreated powder; preferably, the concentration of the sodium hydroxide solution is 1-2 wt%; preferably, the stirring temperature is 40-60 ℃, and the stirring time is 3-5 h;

(ii) adding the pretreated powder into a methanol aqueous solution with the pH value of 7.5-8.0, uniformly mixing to obtain a mixed system, adding a silane coupling agent into the mixed system, stirring and refluxing, and performing post-treatment to obtain the modified iron oxide red or the modified sericite powder or the modified glass beads; preferably, the silane coupling agent is one or more of KH-560, KH570 and JH-N308, and more preferably is KH-560; preferably, the obtained modified iron oxide red or modified sericite powder or modified glass beads contain the silane coupling agent by weight percentage of 0.5-3.5%.

Preferably, the weight part of the epoxy resin E44 is 3-6 parts, and the weight part of the epoxy resin E51 is 15-24 parts.

In a second aspect, the present invention provides a method for preparing the solvent-free drag-reducing coating for pipelines in the first aspect, the method comprising the following steps:

(1) uniformly mixing epoxy resin E44, epoxy resin E51, an active diluent, a defoaming agent, a dispersing agent, a leveling agent, an anti-shrinkage agent, iron oxide red, sericite powder, superfine barium sulfate, talcum powder, zinc phosphate, modified polytetrafluoroethylene powder and an anti-settling agent to obtain a component A; optionally, adding modified glass beads and uniformly mixing to obtain a component A;

(2) and uniformly mixing the component A and the component B to obtain the solvent-free anti-drag coating in the pipeline.

Preferably, step (1) is: firstly, mixing and stirring epoxy resin E44 and epoxy resin E51 with an active diluent for 5-15min, then adding a dispersing agent and a defoaming agent under the stirring condition, continuously stirring for 5-15min, then sequentially adding iron oxide red, sericite powder, superfine barium sulfate, talcum powder, zinc phosphate, modified polytetrafluoroethylene powder and an anti-settling agent under the stirring condition, then continuously stirring for 30-60min, finally adding a leveling agent and an anti-shrinkage agent, and then continuously stirring for 10-20min to obtain a component A.

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

(1) the film forming material in the invention is a mixed resin of epoxy resin E44 and epoxy resin E51, and the toughness and the bending resistance of a paint film are effectively improved by adjusting the proper proportion under the condition of basically not influencing the viscosity.

(2) The invention uses the modified polytetrafluoroethylene powder as the pigment filler, and further improves the smoothness of a paint film formed by the drag reduction coating in the solvent-free pipeline.

(3) The curing agent in the invention is prepared by mixing the polyamide curing agent and the alicyclic amine curing agent, so that the curing speed of a paint film is effectively improved, and the bending resistance of the paint film is kept.

(4) In some preferred embodiments of the invention, the modified iron oxide red, the modified sericite powder and the modified glass beads are used as pigments and fillers, so that the resin dosage for coating the powder can be effectively reduced on the premise of ensuring that the performance of the paint is not reduced, the resin content in the paint film can be effectively reduced, the resin content in the component A in the invention is less than 35%, the resin content is low, and the paint cost can be effectively reduced.

Drawings

FIG. 1 is a graph showing the results of bending a paint film formed using the solvent-free internal drag reducing coating of example 1 of the present invention and the results of salt spray experiments.

FIG. 2 is a graph showing the results of bending a paint film formed using the solvent-free internal drag reducing coating of the present invention in comparative example 6 and a graph showing the results of salt spray experiments.

Detailed Description

In order to make the objects, technical solutions and advantages of the present invention more apparent, the technical solutions of the present invention will be clearly and completely described below with reference to the embodiments of the present invention. It is to be understood that the embodiments described are only a few embodiments of the present invention, and not all embodiments. All other embodiments, which can be obtained by a person skilled in the art without any inventive step based on the embodiments of the present invention, are within the scope of the present invention.

The invention provides a solvent-free type in-pipeline drag reduction coating in a first aspect, which comprises a component A and a component B;

the component A comprises the following components in parts by weight:

1-10 parts (e.g., 1, 1.5, 2, 2.5, 3, 3.5, 4, 4.5, 5, 5.5, 6, 6.5, 7, 7.5, 8, 8.5, 9, 9.5, or 10 parts) of epoxy resin E44, 15-40 parts (e.g., 15, 16, 17, 18, 19, 20, 21, 22, 23, 24, 25, 26, 27, 28, 29, 30, 31, 32, 33, 34, 35, 36, 37, 38, 39, or 40 parts) of epoxy resin E51, 0.5-4.0 parts (e.g., 0.5, 1.0, 1.5, 2.0, 2.5, 3.0, 3.5, or 4.0 parts) of a reactive diluent, 0.1-0.5 parts (e.g., 0.1, 0.15, 0.2, 0.25, 0.3, 0.35, 0.45, 0.5 parts (e.5), 0.0.5, 0.5 parts of a leveling agent, 0.5 parts (e.0.5 parts) of a dispersant, 0.1-0.5 parts (e., 0.1, 0.5 parts) of a dispersant, 0.5 parts (e.5 parts) of a dispersant, 0.0.5 parts) of a dispersant, 0.5 parts (e.5 parts) of a dispersant, 0.0.0.0.5 parts) of a dispersant, 0.0.0.5 parts, 0.0.5 parts, 0.0 parts (0.5 parts) of a dispersant, 0.0.0.5 parts, 0.0.5 parts, 0.0.0.0.5 parts, 0.0.5 parts of a dispersant, 0.5 parts of a dispersant, 0.0.0.5 parts of a dispersant, 0.0.0.0.5 parts of a dispersant, 0.5 parts of a 1 parts of a dispersant, 0.0 parts of a 1 parts of a dispersant, 0.0.0.0.0.5 parts of a dispersant, 0.5 parts of a dispersant, 0 parts of a 1 parts of a dispersant, 0 parts of a dispersant, 0.5 parts of a dispersant, 0 parts of a dispersant, 0.5 parts of a dispersant, 0 parts of a dispersant, 0.5 parts of a dispersant, 0, 0.5 parts of a dispersant, 0, 0.5 parts of a dispersant, 0.0.0.0.0.5 parts of a dispersant, 0, 0.0.5 parts of a dispersant, 0, 0.5 parts of a dispersant, 0, 0.5 parts of a dispersant, 0, 0.0, 0, 0.2, 0.25, 0.3, 0.35, 0.4, 0.45 or 0.5 part) of an anticratering agent, 5 to 15 parts (e.g., 5, 5.5, 6, 6.5, 7, 7.5, 8, 8.5, 9, 9.5, 10, 10.5, 11, 11.5, 12, 12.5, 13, 13.5, 14, 14.5 or 15 parts) of red iron oxide, 5 to 15 parts (e.g., 5, 5.5, 6, 6.5, 7, 7.5, 8, 8.5, 9, 9.5, 10, 10.5, 11, 11.5, 12, 12.5, 13, 13.5, 14, 14.5 or 15 parts) of sericite powder, 10 to 20 parts (e.g., 10, 11, 12, 13, 14, 15, 16, 17, 18, 19 or 20 parts) of ultrafine barium sulfate, 5 to 10 parts (e.g., 5, 5.5, 5, 10, 5, 10, 5, 10, 5, 10, 5, 10, 5, or 15 parts of zinc phosphate, or 15 parts of such as zinc phosphate, 6. 6.6, 7, 7.5, 8, 8.5, 9, 9.5 or 10 parts) of modified polytetrafluoroethylene powder and 0.1 to 1 part (e.g., 0.1, 0.2, 0.3, 0.4, 0.5, 0.6, 0.7, 0.8, 0.9 or 1 part) of an anti-settling agent;

The invention has no special limit to iron oxide red, sericite powder, superfine barium sulfate, zinc sulfate, talcum powder and the like, and can be prepared by adopting products which can be directly purchased in the market; the dispersant, the defoamer, the anti-settling agent, the leveling agent and the anti-cratering agent are not particularly limited, and the dispersant, the defoamer, the anti-settling agent, the leveling agent and the anti-cratering agent which are used for epoxy resin paint and are conventional in the prior art can be adopted.

The film forming resin in the component A of the existing solvent-free epoxy internal drag reduction coating is generally single epoxy resin E51, but the bending resistance of the coating which singly adopts epoxy resin E51 as a film forming substance needs to be further improved. At present, toughened resin is usually introduced into E51 resin to improve the bending resistance of the coating, but the introduction of the toughened resin generally affects the strength, modulus and heat resistance of the material, so that the improvement of the physical, mechanical and thermal properties of the material is limited. The viscosity of the epoxy resin E44 is relatively high, and generally, the introduction of the epoxy resin E44 into the epoxy resin E51 is not considered to improve the bending resistance of the coating. In the invention, the mixed resin of the epoxy resin E44 and the epoxy resin E51 is used as a film forming substance, and the mass ratio of the epoxy resin E44 to the epoxy resin E51 is (1-10): (15-40), more preferably 1: (2.5-8), the strength, modulus and heat resistance of the paint film are guaranteed, the influence on viscosity is small, construction is facilitated, the toughness of the paint film is effectively improved by introducing epoxy resin E44, and the bending resistance of the paint film is improved.

The polytetrafluoroethylene powder can promote the smoothness of a paint film, when the using amount of the polytetrafluoroethylene powder is small, the effect of promoting the smoothness of the paint film is not obvious, and when the using amount of the polytetrafluoroethylene powder is large, the polytetrafluoroethylene powder is easier to float on the surface of the paint film due to poor dispersion performance of the polytetrafluoroethylene powder, so that the effect of promoting the smoothness of the paint film is poor. In addition, the alicyclic amine curing agent and the polyamide curing agent are used for resin curing, so that the temperature and time for curing the paint are effectively reduced, the construction of the drag reduction paint in a solvent-free pipeline is facilitated, the bending resistance of the paint film is kept while the curing speed of the paint film is effectively increased, and the paint (paint) disclosed by the invention is solvent-free, convenient to construct, economic and environment-friendly, and has excellent water resistance, corrosion resistance, wear resistance and excellent resistance reduction.

According to the invention, two epoxy resins are used as film forming substances, and the paint is cured by using the mixed curing agent, so that the paint film has excellent resistance reduction, water resistance, corrosion resistance and wear resistance; and the paint has low resin content, no solvent, economy and environmental protection.

According to some preferred embodiments, the a component comprises the following components in parts by weight:

5-10 parts of epoxy resin E44, 25-40 parts of epoxy resin E51, 0.5-4.0 parts of active diluent, 0.1-0.5 part of defoaming agent, 0.5-1 part of dispersing agent, 0.1-0.5 part of flatting agent, 0.1-0.5 part of anti-shrinkage agent, 5-15 parts of iron oxide red, 5-15 parts of sericite powder, 10-20 parts of superfine barium sulfate, 5-10 parts of talcum powder, 10-15 parts of zinc phosphate, 5-10 parts of modified polytetrafluoroethylene powder and 0.1-1 part of anti-settling agent.

According to some preferred embodiments, the preparation of the modified polytetrafluoroethylene powder comprises the steps of:

(a) dissolving naphthalene in tetrahydrofuran, adding metal sodium, and stirring for 1-2h (such as 1, 1.5 or 2h) under the protection of nitrogen to obtain a modified solution; the mass ratio of the naphthalene to the tetrahydrofuran to the metal sodium is (40-50): (800-1000): (10-15) (e.g., 40:800:10, 40:850:10, 40:900:10, 40:950:10, 40:1000:10, 45:800:10, 45:850:10, 45:900:10, 45:950:10, 45:1000:10, 50:800:10, 50:850:10, 50:900:10, 50:950:10, or 50:1000: 10);

(b) adjusting the temperature of the modification liquid to 5-15 ℃ (for example, 5, 6, 7, 8, 9, 10, 11, 12, 13, 14 or 15 ℃), then soaking polytetrafluoroethylene powder in the modification liquid with the temperature of 5-15 ℃ and stirring for modification for 5-10min (for example, 5, 6, 7, 8, 9 or 10min), then separating the modified polytetrafluoroethylene powder from the modification liquid, and washing and drying to obtain modified polytetrafluoroethylene powder; the present invention is not particularly limited to the separation, and in the specific embodiment of the present invention, for example, the modified polytetrafluoroethylene powder can be separated from the modified solution by suction filtration; the invention has no special requirement on the rotating speed of stirring involved in the preparation process of the modified polytetrafluoroethylene powder, and the conventional rotating speed can be adopted, and can be 200-400 r/min for example.

The particle size of the polytetrafluoroethylene powder adopted in the invention is generally not more than 5 μm, and the invention finds that the modification degree of the polytetrafluoroethylene fine powder is not higher and better, the invention obtains the optimal modification condition of the polytetrafluoroethylene powder through a large number of creative tests, namely preferably, the modification liquid is obtained by only stirring 1-2h after mixing naphthalene, tetrahydrofuran and sodium, and in the modification liquid, the mass ratio of the naphthalene, the tetrahydrofuran and the metal sodium is controlled to be (40-50): (800-1000): (10-15), and the temperature of the modification is controlled to be 5-15 ℃, so that the obtained modified polytetrafluoroethylene powder is more beneficial to improving the smoothness of a paint film, and the paint film has excellent resistance reduction performance.

According to some preferred embodiments, in the step (b), washing is sequentially performed by using acetone and water to clean the modifying solution on the surface of the modified polytetrafluoroethylene powder.

According to some preferred embodiments, the particle size of the polytetrafluoroethylene powder is not greater than 5 μm.

According to some specific embodiments, the preparation of the modified polytetrafluoroethylene powder comprises:

(a) adding 40-50 parts of naphthalene into 800-1000 parts of tetrahydrofuran, stirring to completely dissolve the naphthalene, slowly adding 10-15 parts of sodium metal into the naphthalene, controlling the system temperature at 5-15 ℃ under the protection of nitrogen, and stirring for 1-2 hours to obtain dark brown liquid, namely the modified liquid;

(b) adding polytetrafluoroethylene powder to be modified into the modification liquid at the temperature of 5-15 ℃, stirring for 5-10min, separating the modified polytetrafluoroethylene powder from the modification liquid, soaking the obtained powder in acetone for 3-5 min, cleaning the powder from the acetone, cleaning the powder with water, and naturally drying the obtained powder in the shade to obtain the modified polytetrafluoroethylene powder; the invention does not specifically limit the separation of the powder and the liquid, and the separation is carried out by adopting a suction filtration mode, for example, when the powder is cleaned by water, the separation of the powder and the water is also carried out by adopting the suction filtration mode; the mass ratio of the modifying liquid to the polytetrafluoroethylene powder is (60-100): 1; in the invention, when acetone and water are used for cleaning, the dosage of acetone and water is not particularly limited, for example, the dosage of acetone and/or water is 60-100 times of the weight of the powder.

According to some preferred embodiments, the mass ratio of the component A to the component B is (4-10): 1 (e.g., 4, 4.5:1, 5:1, 5.5:1, 6:1, 6.5:1, 7:1, 7.5:1, 8:1, 8.5:1, 9:1, 9.5:1, or 10: 1); the alicyclic amine curing agent is a low-viscosity alicyclic amine curing agent, and preferably, the alicyclic amine curing agent is one or more of TAC-900 alicyclic amine curing agent, YH-505 alicyclic amine curing agent and PACM alicyclic amine curing agent; in the invention, preferably, the curing agent is 4,4 '-diaminodicyclohexyl methane alicyclic amine curing agent PACM (PACM alicyclic amine curing agent), the modified alicyclic amine curing agent taking 4,4' -diaminodicyclohexyl methane as a main component has small odor, safe use, strong corrosion resistance of cured resin, high mechanical property and toughness, and high curing speed, and can effectively improve the curing speed of the coating; the polyamide curing agent is one or more of 400 polyamide curing agent, 650 polyamide curing agent and 651 polyamide curing agent; and/or the mass ratio of the alicyclic amine curing agent to the polyamide curing agent is (0.5-1.5): 1, preferably 1: 1.

According to some preferred embodiments, the reactive diluent is C _12-14 One or more of Alkyl Glycidyl Ether (AGE), Butyl Glycidyl Ether (BGE), trimethylolpropane triglycidyl ether, phenyl glycidyl ether, 1, 4-butanediol diglycidyl ether (e.g., epoxy reactive diluent 622), preferably C _12-14 An alkyl glycidyl ether; AGE is C _12-14 Alkyl glycidyl ethers of the formula C _12-14 H _25-29 OCH ₂ (CHCH ₂ ) O; the invention discovers that the reactive diluent AGE can not only reduce the system viscosity, but also improve the construction feasibility of the paint vehicle; the toughness of the paint film can be effectively enhanced, the problem of large brittleness of the cured epoxy resin E51 film can be solved, and the paint is economical and environment-friendly; and the reactive diluent also participates in the curing reaction, and the properties of the cured product are maintained.

The types of the defoaming agent, the dispersing agent, the leveling agent, the anti-cratering agent, the anti-settling agent and the like are not particularly limited, and conventional defoaming agents, dispersing agents, leveling agents, anti-cratering agents and anti-settling agents suitable for coating materials can be adopted; in some preferred embodiments, the defoaming agent is a silicone defoaming agent, the silicone defoaming agent can be one or more of Tego-2700 defoaming agent, Tego-30 defoaming agent and Bick BYK-072 defoaming agent, and products such as Tego-2700 defoaming agent (chemical component: silicone acrylate), Tego-30 defoaming agent (chemical component: organic modified polysiloxane emulsion containing gas phase silicon dioxide), Bick BYK-072 defoaming agent (chemical component: foam breaking polysiloxane solution) and the like can be directly purchased from the market; the dispersant is a macromolecular block copolymer containing pigment-philic groups, more preferably, the dispersant can be one or more of BYK-163 dispersant, BYK-170 dispersant, BYK-161 dispersant and Tego-650 dispersant, and the products can be directly purchased from the market; the flatting agent is a polysiloxane compound, and can be one or more of BYK-333 flatting agent, DC-51 flatting agent and BYK-335 flatting agent, and products such as BYK-333 flatting agent (chemical component: polyether modified polydimethylsiloxane), DC-51 flatting agent (chemical component: pasty ultra-high molecular weight polydimethylsiloxane dispersion liquid), BYK-335 flatting agent (chemical component: polyether modified polydimethylsiloxane) and the like can be directly purchased from the market; the anti-shrinkage agent is an organic silicon anti-shrinkage agent, the anti-shrinkage agent can be one or more of 2266 anti-shrinkage agent, Tego Twin4100 anti-shrinkage agent and BYK-341 anti-shrinkage agent, and products such as the 2266 anti-shrinkage agent (chemical component: modified polysiloxane solution), the Tego Twin4100 anti-shrinkage agent (chemical component: organic silicon geminal structure siloxane), the BYK-341 anti-shrinkage agent (chemical component: polyether modified polydimethylsiloxane solution) and the like can be directly purchased from the market; and/or the anti-settling agent is one or more of organic bentonite, fumed silica and polyolefin wax, and preferably, the anti-settling agent products can be directly purchased from the market.

According to some preferred embodiments, the iron oxide red is modified iron oxide red, and the sericite powder is modified sericite powder; and/or the a-component further comprises 5-15 parts (e.g., 5, 6, 7, 8, 9, 10, 11, 12, 13, 14, or 15 parts) of modified glass microspheres.

As is well known, if the content of the resin in the solvent-free type drag reduction coating in the pipeline is too low, the coating adhesion of the coating is affected, and the overall performance of a paint film is poor due to insufficient coating of the resin on powder, so that the epoxy resin content of the component A in the existing solvent-free type drag reduction coating in the pipeline is generally more than 35%, and the resin content in a part of the formula can even reach 60%. However, too high a resin content increases paint cost and limits the development of solvent-free drag-reducing coatings in pipelines. Although there is a constant desire to reduce the cost of producing coatings, there has been no adequate solution to this problem, taking into account the properties of the paint film.

In some preferred embodiments, modified iron oxide red, modified sericite powder and/or modified glass beads are used as a filler for the first time, so that the content of resin in the coating is effectively reduced, the component A only needs to contain 15-30% by mass of epoxy resin, and more preferably 18-30%, the solvent-free in-pipeline drag reduction coating can achieve the paint film performance equivalent to that of the coating with the resin content of more than 35%, and the formed coating is ensured to have excellent water resistance, corrosion resistance, wear resistance and excellent drag reduction, and also has the coating adhesion equivalent to that of the coating with high resin content; the solvent-free type drag reduction coating in the pipeline has excellent overall performance of a paint film, but the resin content is extremely low and is far lower than the conventional requirement by more than 35 percent, compared with the coating in the prior art, the solvent-free type drag reduction coating in the pipeline has the effect of remarkably reducing the cost of the coating, and the progress achieved in the preferable technical scheme of the invention is unprecedented.

According to some preferred embodiments, the preparation of the modified iron oxide red or the modified sericite powder or the modified glass microspheres comprises the following steps:

(i) adding iron oxide red or sericite powder or glass beads into a sodium hydroxide solution, stirring, and performing post-treatment to obtain pretreated powder; the invention has no special limit to the iron oxide red, the sericite powder and the glass beads, and only needs to adopt products which can be directly purchased in the market; preferably, the concentration of the sodium hydroxide solution is 1-2 wt%; preferably, the stirring temperature is 40-60 ℃ (e.g., 40 ℃, 45 ℃, 50 ℃, 55 ℃ or 60 ℃), and the stirring time is 3-5h (e.g., 3, 3.5, 4, 4.5 or 5 h); preferably, the post-treatment comprises suction filtration, washing and drying, and preferably, the drying temperature is 80 to 120 ℃ (for example, 80 ℃, 85 ℃, 90 ℃, 95 ℃, 100 ℃, 105 ℃, 110 ℃, 115 ℃ or 120 ℃), and the drying time is 2 hours or more.

(ii) Adding the pretreated powder into a methanol aqueous solution with the pH value of 7.5-8.0, uniformly mixing to obtain a mixed system, adding a silane coupling agent into the mixed system, stirring and refluxing, and performing post-treatment to obtain the modified iron oxide red or the modified sericite powder or the modified glass beads; the invention has the same modification method for the iron oxide red, the sericite powder and the glass beads; in the invention, the modified iron oxide red, the modified sericite powder and the modified glass beads are collectively called as modified powder; in the invention, the amount of the methanol aqueous solution can be, for example, 5 to 25 times of the mass amount of the pretreatment powder; the methanol aqueous solution is prepared from methanol and water according to the mass ratio of (8-12): 1, mixing; in the present invention, the pH of the aqueous methanol solution may be adjusted to 7.5 to 8.0 using, for example, ammonia water; preferably, the silane coupling agent is one or more of KH-560, KH570 and JH-N308, and is preferably KH-560; preferably, the obtained modified iron oxide red or modified sericite powder or modified glass beads contains 0.5 to 3.5 mass percent (e.g., 0.5%, 1.0%, 1, 5%, 2.0%, 2.5%, 3.0%, 3.5%) of the silane coupling agent; preferably, the particle size of the obtained modified iron oxide red or modified sericite powder or modified glass beads is 200-400 meshes (for example, 200 meshes, 250 meshes, 300 meshes, 350 meshes or 400 meshes), and preferably 300 meshes; preferably, the temperature of the stirring reflux is 60-80 ℃ (for example, 60 ℃, 65 ℃, 70 ℃, 75 ℃ or 80 ℃), and the time of the stirring reflux is 1-3h (for example, 1, 1.5, 2, 2.5 or 3 h); preferably, in step (ii), the post-treatment comprises suction filtration, washing, drying, crushing, grinding and sieving; the rotating speed of stirring involved in the preparation process of the modified powder is not particularly required, and the conventional rotating speed can be adopted, and can be 200-400 r/min for example.

According to some specific embodiments, step (i) is: adding iron oxide red or sericite powder or glass beads to be modified into a sodium hydroxide solution with the concentration of 1-2 wt%, stirring at the temperature of 40-60 ℃ for 3-5h, performing suction filtration to obtain powder, repeatedly washing with distilled water until the washing liquid is neutral, and finally drying the filtered product in a drying oven at the temperature of 80-120 ℃ for more than 2 h.

According to some specific embodiments, said step (ii) is: adding 50-100 parts of mixed solution of methanol and water into stirring equipment with a reflux device, wherein the mass ratio of the methanol to the water is 10: 1; adjusting pH value of the system to 7.5-8.0 with ammonia water, slowly adding pretreated powder under stirring, slowly adding silane coupling agent KH-560, stirring at 60-80 deg.C for 1-3 hr. Then cooling and filtering to obtain a filtered product. Repeatedly washing with distilled water until the washing liquid is neutral, drying the filtered product in a drying oven at 80-120 deg.C for more than 2h, pulverizing, grinding, and sieving with 300 mesh sieve to obtain powder modified by silane coupling agent KH-560.

According to the invention, sodium hydroxide solution is used for pretreating powder before modifying the powder, and then silane coupling agent is used for modifying, so that compared with the powder obtained by directly modifying with silane coupling agent, the obtained modified powder can effectively reduce the resin content in the coating on the premise of ensuring that the performance of the coating is not reduced; in addition, the pretreated powder is modified with the silane coupling agent in the methanol aqueous solution with the pH value of 7.5-8.0, and compared with the modification in the neutral or strong-alkaline methanol aqueous solution, the method is more beneficial to effectively reducing the resin content in the coating on the premise of ensuring that the performance of the coating is not reduced; the invention discovers that if the pH value is too low, the reaction activity of the silane coupling agent is low, and the silane coupling agent does not fully react with the powder; too high pH value can lead the silane coupling agent to generate too much polymerization, thus leading the modification effect to be poor; in the present invention, the modification is preferably performed in an aqueous methanol solution having a pH of 7.5 to 8.0.

The modified iron oxide red and the modified sericite powder are used, so that the compatibility of the modified iron oxide red and the modified sericite powder in a resin system can be obviously improved, the agglomeration of the modified iron oxide red and the modified sericite powder is greatly reduced, and the dispersion performance of the modified sericite powder is improved; the invention discovers that the modified glass beads are used as oleophilic pigment and filler, so that the acid and alkali resistance of a paint film can be improved, the spherical particles determine that the paint film has smaller specific surface area and lower oil absorption rate, and meanwhile, the modified glass beads can more effectively reduce the resin dosage for coating powder, greatly reduce the resin dosage in the using process and ensure that other properties of the paint are not reduced.

According to some preferred embodiments, in the component a, the mass ratio of the modified iron oxide red, the modified sericite powder and the modified glass beads is (0.6-0.8): 1: (0.35-0.45); a large number of tests prove that in the component A, the optimal dosage ratio of the modified iron oxide red, the modified sericite powder and the modified glass beads is (0.6-0.8): 1: (0.35-0.45), so that the performance of the coating can be better ensured not to be reduced, and the resin content in the coating can be more effectively reduced.

According to some preferred embodiments, the epoxy resin E44 is present in an amount of 3 to 6 parts by weight (e.g., 3, 3.5, 4, 4.5, 5, 5.5, or 6 parts) and the epoxy resin E51 is present in an amount of 15 to 24 parts by weight (e.g., 15, 16, 17, 18, 19, 20, 21, 22, 23, or 24 parts).

According to some specific embodiments, the a component comprises the following components in parts by weight:

3-6 parts of epoxy resin E44, 15-24 parts of epoxy resin E51, 0.5-4.0 parts of active diluent, 0.1-0.5 part of defoaming agent, 0.5-1 part of dispersing agent, 0.1-0.5 part of flatting agent, 0.1-0.5 part of anti-shrinkage agent, 5-15 parts of modified iron oxide red, 5-15 parts of modified sericite powder, 5-15 parts of modified glass beads, 10-20 parts of superfine barium sulfate, 5-10 parts of talcum powder, 10-15 parts of zinc phosphate, 5-10 parts of modified polytetrafluoroethylene powder and 0.1-1 part of anti-settling agent.

In a second aspect, the present invention provides a method for preparing a solvent-free drag-reducing coating for pipelines according to the first aspect of the present invention, the method comprising the steps of:

(2) uniformly mixing the component A and the component B to obtain a solvent-free in-pipeline drag reduction coating; specifically, the solvent-free internal drag reduction coating comprises a component A and a component B, and the component A and the component B are uniformly mixed before use to obtain the solvent-free internal drag reduction coating.

According to some preferred embodiments, step (1) is: firstly, mixing and stirring epoxy resin E44 and epoxy resin E51 with an active diluent for 5-15min, then adding a dispersing agent and a defoaming agent under the stirring condition, continuously stirring for 5-15min, then sequentially adding iron oxide red, sericite powder, superfine barium sulfate, talcum powder, zinc phosphate, modified polytetrafluoroethylene powder and an anti-settling agent under the stirring condition, then continuously stirring for 30-60min, finally adding a leveling agent and an anti-shrinkage agent, and then continuously stirring for 10-20min to obtain a component A.

According to some specific embodiments, the step (1) is: adding 1-10 parts of epoxy resin E44, 25-40 parts of epoxy resin E51 and 0.5-2.0 parts of reactive diluent into a stirring device, and stirring for 5-15min, wherein the reactive diluent can effectively reduce the viscosity of the system and is convenient for adding powder at the later stage; then adding 0.5-1.0 part of dispersing agent and 0.1-0.5 part of defoaming agent under stirring state, and continuing stirring for 5-15min, wherein the dispersing agent and the defoaming agent are added before the powder, so that the overflow of system foam and the uniform dispersion of the powder are facilitated; then adding 5-15 parts of iron oxide red, 5-15 parts of sericite powder, 10-20 parts of superfine barium sulfate, 5-10 parts of talcum powder, 10-15 parts of zinc phosphate, 5-10 parts of modified polytetrafluoroethylene powder and 0.1-1.0 part of anti-settling agent in sequence under the stirring state; after the powder is completely added, continuously stirring for 30-60min to ensure that the powder is uniformly dispersed in the system; finally, 0.1 to 0.5 part of flatting agent and 0.1 to 0.5 part of anti-shrinkage agent are added and stirred for 10 to 20min to obtain a component A; the stirring speed in the preparation of the component A is not particularly limited, and a conventional stirring speed can be adopted, and can be 600-900 r/min.

According to some specific embodiments, the step (1) is: adding 3-6 parts of epoxy resin E44, 15-24 parts of epoxy resin E51 and 0.5-4.0 parts of reactive diluent into a stirring device, and stirring for 5-15min, wherein the reactive diluent can effectively reduce the viscosity of the system, so that the later-stage powder can be conveniently added; then adding 0.5-1.0 part of dispersing agent and 0.1-0.5 part of defoaming agent under the stirring state, and continuing stirring for 5-15min, wherein the dispersing agent and the defoaming agent are added before the powder, so that the overflow of system foam and the uniform dispersion of the powder are facilitated; then adding 5-15 parts of modified iron oxide red, 5-15 parts of modified sericite powder, 10-20 parts of superfine barium sulfate, 5-15 parts of modified glass beads, 5-10 parts of talcum powder, 10-15 parts of zinc phosphate, 5-10 parts of modified polytetrafluoroethylene powder and 0.1-1.0 part of anti-settling agent in sequence under the stirring state; after the powder is completely added, continuously stirring for 30-60min to ensure that the powder is uniformly dispersed in the system; finally, 0.1 to 0.5 portion of flatting agent and 0.1 to 0.5 portion of anti-shrinkage agent are added and stirred for 10 to 20min to obtain the component A.

In particular, the term "part" as used herein means "part by weight".

The invention will be further illustrated by way of example, but the scope of protection is not limited to these examples. The present invention is capable of other embodiments, and various changes and modifications may be made by one skilled in the art without departing from the spirit and scope of the invention as defined in the appended claims.

Example 1

Preparing modified polytetrafluoroethylene powder:

(a) adding 40g of naphthalene into 1000g of tetrahydrofuran, stirring to completely dissolve the naphthalene, then slowly adding 13g of metal sodium into the naphthalene, controlling the system temperature at 15 ℃ under the protection of nitrogen, and stirring for 1.5h to obtain dark brown liquid, namely the modified liquid.

(b) Adding 15g of polytetrafluoroethylene powder into the modifying solution at the temperature of 15 ℃, stirring for 5min, separating the modified polytetrafluoroethylene powder from the modifying solution, soaking the obtained powder in 1000g of acetone for 5min for cleaning, separating the powder from the acetone, cleaning the powder with water, and naturally drying the obtained powder in the shade to obtain the modified polytetrafluoroethylene powder.

The preparation of the solvent-free drag reduction coating in the pipeline comprises the following steps:

s1, preparation of the component A:

adding 5g of epoxy resin E44, 35g of epoxy resin E51 and 3.0g of active diluent AGE into a stirring device, and stirring for 10 min; adding 0.8g of BYK-163 dispersing agent and 0.3g of Tego-2700 defoaming agent under the stirring state, and continuing stirring for 10 min; then, 10g of iron oxide red, 10g of sericite powder, 15g of ultrafine barium sulfate, 5g of talcum powder, 15g of zinc phosphate, 10g of modified polytetrafluoroethylene powder and 0.2g of organic bentonite are added in sequence under the stirring state; after the powder is completely added, continuously stirring for 40 min; and finally, adding 0.2g of BYK-333 leveling agent and 0.4g of Tego Twin4100 anti-shrinkage agent, and stirring for 20min to obtain the component A.

The component S2 and the component B are formed by mixing 4,4' -diaminodicyclohexyl methane alicyclic amine curing agent PACM and 650 polyamide curing agent according to the mass ratio of 1: 1; and uniformly mixing the component A and the component B according to the mass ratio of 5:1 to obtain the solvent-free anti-drag coating in the pipeline.

Example 2

Preparing modified polytetrafluoroethylene powder:

s1, preparation of the component A:

adding 10g of epoxy resin E44, 40g of epoxy resin E51 and 3.0g of active diluent AGE into a stirring device, and stirring for 10 min; adding 0.8g of BYK-163 dispersing agent and 0.3g of Tego-2700 defoaming agent under the stirring state, and continuing stirring for 10 min; then, 10g of iron oxide red, 15g of sericite powder, 10g of ultrafine barium sulfate, 5g of talcum powder, 15g of zinc phosphate, 10g of modified polytetrafluoroethylene powder and 0.2g of organic bentonite are added in sequence under the stirring state; after the powder is completely added, continuously stirring for 40 min; and finally, adding 0.2g of BYK-333 leveling agent and 0.4g of Tego Twin4100 anti-shrinkage agent, and stirring for 20min to obtain the component A.

Example 3

Preparing modified polytetrafluoroethylene powder:

Preparing modified powder:

adding 12g of powder (iron oxide red or sericite powder or glass beads) to be modified into 100g of a 1.5 wt% sodium hydroxide aqueous solution, stirring at 60 ℃ for 5 hours, performing suction filtration to obtain powder, repeatedly washing the powder with distilled water until the washing liquid is neutral, and finally drying the filtered product in a drying oven at 80 ℃ for 2 hours to obtain pretreated powder;

adding 100g of mixed solution (methanol aqueous solution) of methanol and water into stirring equipment with a reflux device, wherein the mass ratio of the methanol to the water is 10: 1; adjusting the pH value of the system to 8.0 by using ammonia water, slowly adding the pretreated powder into the system under the stirring state, slowly dripping 0.24g of silane coupling agent KH-560 into the pretreated powder after uniform stirring, setting the temperature of a stirring device to 80 ℃ after the addition is finished, and stirring and refluxing for 2 hours. Then cooling and filtering to obtain a filtered product. Repeatedly washing with distilled water until the washing liquid is neutral, drying the filtered product in a drying oven at 100 deg.C for 3h, pulverizing, grinding, and sieving with 300 mesh sieve to obtain modified powder modified with silane coupling agent KH-560.

The modified powder is modified iron oxide red, modified sericite powder and modified glass beads; the modified iron oxide red, the modified sericite powder and the modified glass beads are prepared by the same method in the first step and the second step.

s1, preparation of the component A:

adding 3g of epoxy resin E44, 21g of epoxy resin E51 and 3.0g of active diluent AGE into a stirring device, and stirring for 10 min; adding 0.8g of BYK-163 dispersing agent and 0.3g of Tego-2700 defoaming agent under the stirring state, and continuing stirring for 10 min; then, 10g of modified iron oxide red, 10g of modified sericite powder, 15g of superfine barium sulfate, 10g of modified glass beads, 5g of talcum powder, 15g of zinc phosphate, 10g of modified polytetrafluoroethylene powder and 0.2g of organic bentonite are added in sequence under the stirring state; after the powder is completely added, continuously stirring for 40 min; and finally, adding 0.2g of BYK-333 leveling agent and 0.4g of Tego Twin4100 anti-shrinkage agent, and stirring for 20min to obtain the component A.

Example 4

Example 4 is essentially the same as example 3, except that:

in step S1, the a component is prepared by:

adding 3g of epoxy resin E44, 15g of epoxy resin E51 and 3.0g of active diluent AGE into a stirring device, and stirring for 10 min; adding 0.8g of BYK-163 dispersing agent and 0.3g of Tego-2700 defoaming agent under the stirring state, and continuing stirring for 10 min; then, 10g of modified iron oxide red, 10g of modified sericite powder, 15g of superfine barium sulfate, 10g of modified glass beads, 5g of talcum powder, 15g of zinc phosphate, 10g of modified polytetrafluoroethylene powder and 0.2g of organic bentonite are added in sequence under the stirring state; after the powder is completely added, continuously stirring for 40 min; and finally, adding 0.2g of BYK-333 leveling agent and 0.4g of Tego Twin4100 anti-shrinkage agent, and stirring for 20min to obtain the component A.

Example 5

Example 5 is essentially the same as example 3, except that:

in step S1, preparation of a component a:

adding 3g of epoxy resin E44, 15g of epoxy resin E51 and 3.0g of active diluent AGE into a stirring device, adding 0.8g of BYK-163 dispersing agent and 0.3g of Tego-2700 defoaming agent under the stirring state, and continuing stirring for 20 min; then, 10g of modified iron oxide red, 14.3g of modified sericite powder, 15g of superfine barium sulfate, 5.7g of modified glass beads, 5g of talcum powder, 15g of zinc phosphate, 10g of modified polytetrafluoroethylene powder and 0.2g of organic bentonite are added in sequence under the stirring state; after the powder is completely added, continuously stirring for 30 min; finally, 0.2g of BYK-333 leveling agent and 0.4g of Tego Twin4100 anti-cratering agent are added and stirred for 50min to obtain the component A.

When the modified iron oxide red powder is prepared, in the step I, the using amount of the iron oxide red is 12 g; in the second step, KH-560 is used in an amount of 0.24 g.

When the modified sericite powder is prepared, in the step I, the using amount of the sericite powder is 15 g; in the second step, KH-560 is used in an amount of 0.3 g.

When the modified glass beads are prepared, in the step I, the using amount of the glass beads is 12 g; in the second step, KH-560 is used in an amount of 0.24 g.

Example 6

Example 6 is essentially the same as example 3, except that:

in step S1, the a component is prepared by:

adding 5.7g of epoxy resin E44, 40g of epoxy resin E51 and 3.0g of active diluent AGE into a stirring device, stirring for 10min, adding 0.8g of BYK-163 dispersing agent and 0.3g of Tego-2700 defoaming agent under the stirring state, and continuing stirring for 10 min; then, 10g of modified iron oxide red, 10g of modified sericite powder, 15g of superfine barium sulfate, 10g of modified glass beads, 5g of talcum powder, 15g of zinc phosphate, 10g of modified polytetrafluoroethylene powder and 0.2g of organic bentonite are added in sequence under the stirring state; after the powder is completely added, continuously stirring for 40 min; and finally, adding 0.2g of BYK-333 leveling agent and 0.4g of Tego Twin4100 anti-shrinkage agent, and stirring for 20min to obtain the component A.

Example 7

Example 7 is essentially the same as example 3, except that:

the modified powder was prepared by directly preparing a modified powder without including the step (r) in example 3 by:

adding 100g of a mixed solution (methanol aqueous solution) of methanol and water into a stirring device with a reflux device, wherein the mass ratio of the methanol to the water is 10: 1; adjusting the pH value of the system to 8.0 by using ammonia water, slowly adding 12g of powder (iron oxide red or sericite powder or glass microspheres) to be modified into the system under the stirring state, slowly dripping 0.24g of silane coupling agent KH-560 into the system after uniform stirring, setting the temperature of a stirring device to 80 ℃ after the adding is finished, and stirring and refluxing for 2 hours. Then cooling and filtering to obtain a filtered product. Repeatedly washing with distilled water until the washing liquid is neutral, drying the filtered product in a drying oven at 100 deg.C for 3h, pulverizing, grinding, and sieving with 300 mesh sieve to obtain modified powder modified with silane coupling agent KH-560.

The modified powder is modified iron oxide red, modified sericite powder and modified glass beads; the modified iron oxide red, the modified sericite powder and the modified glass beads are prepared by the same method.

Example 8

Example 8 is essentially the same as example 3, except that:

in the preparation of the modified powder, the step two is as follows: adding 100g of a mixed solution (methanol aqueous solution) of methanol and water into a stirring device with a reflux device, wherein the mass ratio of the methanol to the water is 10: 1; slowly adding the pretreated powder under stirring, slowly adding 0.24g of silane coupling agent KH-560 dropwise after stirring, setting the temperature of the stirring device at 80 deg.C, and stirring and refluxing for 2 hr. Then cooling and filtering to obtain a filtered product. Repeatedly washing with distilled water until the washing liquid is neutral, drying the filtered product in a drying oven at 100 deg.C for 3h, pulverizing, grinding, and sieving with 300 mesh sieve to obtain modified powder modified with silane coupling agent KH-560.

Example 9

Example 9 is essentially the same as example 3, except that:

in the preparation of the modified powder, the step two is as follows: adding 100g of a mixed solution (methanol aqueous solution) of methanol and water into stirring equipment with a reflux device, wherein the mass ratio of the methanol to the water is 10: 1; adjusting the pH value of the system to 9.0 by using ammonia water, slowly adding the pretreated powder into the system under the stirring state, slowly dripping 0.24g of silane coupling agent KH-560 into the pretreated powder after uniform stirring, setting the temperature of a stirring device to 80 ℃ after the addition is finished, and stirring and refluxing for 2 hours. Then cooling and filtering to obtain a filtered product. Repeatedly washing with distilled water until the washing liquid is neutral, drying the filtered product in a drying oven at 100 deg.C for 3h, pulverizing, grinding, and sieving with 300 mesh sieve to obtain modified powder modified by silane coupling agent KH-560.

Comparative example 1

Comparative example 1 is substantially the same as example 1 except that:

preparing modified polytetrafluoroethylene powder:

(a) adding 30g of naphthalene into 1000g of tetrahydrofuran, stirring to completely dissolve the naphthalene, then slowly adding 8g of metal sodium into the naphthalene, controlling the system temperature at 15 ℃ under the protection of nitrogen, and stirring for 1.5h to obtain dark brown liquid, namely the modified liquid.

Comparative example 2

Comparative example 2 is substantially the same as example 1 except that:

preparing modified polytetrafluoroethylene powder:

(a) adding 30g of naphthalene into 1000g of tetrahydrofuran, stirring to completely dissolve the naphthalene, then slowly adding 8g of metal sodium into the naphthalene, controlling the system temperature at 30 ℃ under the protection of nitrogen, and stirring for 2 hours to obtain dark brown liquid, namely the modified liquid.

(b) Adding 15g of polytetrafluoroethylene powder into the modification solution at the temperature of 30 ℃, stirring for 5min, separating the modified polytetrafluoroethylene powder from the modification solution, soaking the obtained powder in 1000g of acetone for 5min for cleaning, separating the powder from the acetone, cleaning the powder with water, and naturally drying the obtained powder in the shade to obtain the modified polytetrafluoroethylene powder.

Comparative example 3

Comparative example 3 is substantially the same as example 1 except that:

preparing modified polytetrafluoroethylene powder:

(a) adding 120g of naphthalene into 1000g of tetrahydrofuran, stirring to completely dissolve the naphthalene, then slowly adding 25g of sodium metal into the mixture, and stirring for 1.5 hours under the protection of nitrogen and at the system temperature of 2 ℃ to obtain dark brown liquid, namely the modified liquid.

(b) Adding 15g of polytetrafluoroethylene powder into the modifying solution at the temperature of 2 ℃, stirring for 5min, separating the modified polytetrafluoroethylene powder from the modifying solution, soaking the obtained powder in 1000g of acetone for 5min for cleaning, separating the powder from the acetone, cleaning the powder with water, and naturally drying the obtained powder in the shade to obtain the modified polytetrafluoroethylene powder.

Comparative example 4

Comparative example 4 is substantially the same as example 1 except that:

preparing modified polytetrafluoroethylene powder:

(a) adding 120g of naphthalene into 1000g of tetrahydrofuran, stirring to completely dissolve the naphthalene, then slowly adding 25g of metal sodium into the naphthalene, controlling the system temperature at 30 ℃ under the protection of nitrogen, and stirring for 1.5h to obtain dark brown liquid, namely the modified liquid.

Comparative example 5

Comparative example 5 is substantially the same as example 1 except that:

when the component A is prepared, 10g of polytetrafluoroethylene powder is adopted to replace 10g of modified polytetrafluoroethylene powder.

Does not include the preparation of modified polytetrafluoroethylene powder.

Comparative example 6

Comparative example 6 is substantially the same as example 3 except that:

when the component A is prepared, 10g of iron oxide is used for replacing 10g of modified iron oxide red, 10g of sericite powder is used for replacing 10g of modified sericite powder, and 10g of glass beads is used for replacing 10g of modified glass beads.

Does not include the preparation of modified powder (modified iron oxide red, modified sericite powder and modified glass micro-beads).

Comparative example 7

Preparing modified polytetrafluoroethylene powder:

(a) adding 40g of naphthalene into 1000g of tetrahydrofuran, stirring to completely dissolve the naphthalene, then slowly adding 13g of metal sodium into the naphthalene, and stirring for 1.5 hours under the protection of nitrogen and at the system temperature of 15 ℃ to obtain dark brown liquid, namely the modified liquid.

s1, preparation of the component A: adding 3g of epoxy resin E44, 21g of epoxy resin E51 and 3.0g of reactive diluent AGE into a stirring device, and stirring for 10 min; adding 0.8g of BYK-163 dispersing agent and 0.3g of Tego-2700 defoaming agent under the stirring state, and continuing stirring for 10 min; then, 10g of iron oxide red, 10g of sericite powder, 15g of ultrafine barium sulfate, 10g of glass microspheres, 5g of talcum powder, 15g of zinc phosphate, 10g of modified polytetrafluoroethylene powder, 0.2g of organic bentonite and 0.6g of silane coupling agent KH-560 are added in sequence under the stirring state; after the powder materials are completely added, stirring for 40 min; and finally, adding 0.2g of BYK-333 leveling agent and 0.4g of Tego Twin4100 anti-shrinkage agent, and stirring for 20min to obtain the component A.

The solvent-free type in-pipeline drag reduction coating in the embodiments 1 to 9 and the comparative examples 1 to 7 is subjected to performance detection, and detection data are respectively shown in the following tables 1 and 2.

The invention carries out performance detection on the pull-off method adhesion and the contact angle of the coating formed by the solvent-free type in-pipeline drag reduction coating in the examples 1 to 9 and the comparative examples 1 to 7, and the result is shown in the table 3. The coating pull-off method adhesion test execution standard is as follows: GB 5210-85 coating adhesion determination method. Contact angle test performance criteria: GB/T30447 and 2013 nanometer film contact angle measurement method. The method uses contact angle data to judge the dispersion effect of the polytetrafluoroethylene powder in the coating; the polytetrafluoroethylene powder has low surface energy and large contact angle with water due to the F element. If the polytetrafluoroethylene powder is uniformly dispersed in the coating, the contact angle between each point on the surface of the paint film and water is uniform, the average contact angle is large, and the paint film is smoother; if the polytetrafluoroethylene is unevenly dispersed in the paint, the contact angle between each point on the surface of the paint film and water is greatly different, and the average contact angle is small, so that the paint film is not smooth.

TABLE 3

As can be seen from the results in tables 1 to 3, the solvent-free in-pipe drag reduction coating of the present invention has excellent drag reduction properties, water resistance, corrosion resistance, abrasion resistance, and the like; the paint has the advantages of low resin content, strong adhesive force with a base material, no solvent, economy, environmental protection, good flexibility, capability of being constructed at the bent part of a pipeline, smoother paint film surface and the like

The invention has not been described in detail and is in part known to those of skill in the art.

Finally, it should be noted that: the above examples are only intended to illustrate the technical solution of the present invention, but not to limit it; although the present invention has been described in detail with reference to the foregoing embodiments, it will be understood by those of ordinary skill in the art that: the technical solutions described in the foregoing embodiments may still be modified, or some technical features may be equivalently replaced; and such modifications or substitutions do not depart from the spirit and scope of the corresponding technical solutions of the embodiments of the present invention.

Claims

1. A solvent-free drag reduction coating in a pipeline is characterized in that:

the solvent-free drag reduction coating in the pipeline comprises a component A and a component B;

the component A comprises the following components in parts by weight:

1-10 parts of epoxy resin E44, 15-40 parts of epoxy resin E51, 0.5-4 parts of reactive diluent, 0.1-0.5 part of defoaming agent, 0.5-1 part of dispersing agent, 0.1-0.5 part of flatting agent, 0.1-0.5 part of anti-shrinkage agent, 5-15 parts of iron oxide red, 5-15 parts of sericite powder, 10-20 parts of superfine barium sulfate, 5-10 parts of talcum powder, 10-15 parts of zinc phosphate, 5-10 parts of modified polytetrafluoroethylene powder and 0.1-1 part of anti-settling agent;

2. The solvent-free drag-reducing coating in pipelines as claimed in claim 1, wherein the preparation of the modified polytetrafluoroethylene powder comprises the following steps:

3. The solvent-free drag reducing coating for pipelines according to claim 2, characterized in that:

in the step (b), washing is carried out by sequentially adopting acetone and water; and/or

The particle size of the polytetrafluoroethylene powder is not more than 5 mu m.

4. The solvent-free drag reducing coating for pipelines according to claim 1, characterized in that:

the mass ratio of the component A to the component B is (4-10): 1;

the alicyclic amine curing agent is a low-viscosity alicyclic amine curing agent, and preferably, the alicyclic amine curing agent is one or more of TAC-900 alicyclic amine curing agent, YH-505 alicyclic amine curing agent and PACM alicyclic amine curing agent;

the polyamide curing agent is one or more of 400 polyamide curing agent, 650 polyamide curing agent and 651 polyamide curing agent; and/or

The mass ratio of the alicyclic amine curing agent to the polyamide curing agent is (0.5-1.5): 1, preferably 1: 1.

5. The solvent-free drag reducing coating for pipelines according to claim 1, characterized in that:

the active diluent is C _12-14 One or more of alkyl glycidyl ether, butyl glycidyl ether, trimethylolpropane triglycidyl ether, phenyl glycidyl ether and 1, 4-butanediol diglycidyl ether, preferably C _12-14 An alkyl glycidyl ether;

the defoaming agent is an organic silicon defoaming agent;

the dispersing agent is a macromolecular block copolymer containing pigment-philic groups;

the leveling agent is a polysiloxane compound;

the anti-shrinkage agent is an organic silicon anti-shrinkage agent; and/or

The anti-settling agent is one or more of organic bentonite, fumed silica and polyolefin wax.

6. The solvent-free drag reducing coating for pipelines according to any one of claims 1 to 5, characterized in that:

the iron oxide red is modified iron oxide red, and the sericite powder is modified sericite powder; and/or

The component A also comprises 5-15 parts of modified glass beads.

7. The solvent-free drag-reducing coating for pipelines according to claim 6, wherein the preparation of the modified iron oxide red or the modified sericite powder or the modified glass beads comprises the following steps:

(ii) adding the pretreated powder into a methanol aqueous solution with the pH value of 7.5-8.0, uniformly mixing to obtain a mixed system, adding a silane coupling agent into the mixed system, stirring and refluxing, and performing post-treatment to obtain the modified iron oxide red or the modified sericite powder or the modified glass beads; preferably, the silane coupling agent is one or more of KH-560, KH570 and JH-N308, and more preferably is a KH-560 silane coupling agent; preferably, the obtained modified iron oxide red or modified sericite powder or modified glass beads contain the silane coupling agent by weight percentage of 0.5-3.5%.

8. The solvent-free drag reducing coating for pipelines according to claim 6, wherein:

the epoxy resin E44 is 3-6 parts by weight, and the epoxy resin E51 is 15-24 parts by weight.

9. The method for preparing a solvent-free drag reducing coating for pipelines according to any of claims 1 to 8, comprising the steps of:

10. The method of claim 9, wherein:

the step (1) is as follows: firstly, mixing and stirring epoxy resin E44 and epoxy resin E51 with an active diluent for 5-15min, then adding a dispersing agent and a defoaming agent under the stirring condition, continuously stirring for 5-15min, then sequentially adding iron oxide red, sericite powder, superfine barium sulfate, talcum powder, zinc phosphate, modified polytetrafluoroethylene powder and an anti-settling agent under the stirring condition, then continuously stirring for 30-60min, finally adding a leveling agent and an anti-shrinkage agent, and then continuously stirring for 10-20min to obtain a component A.