A pipeline inner wall anticorrosive coating and a preparation method thereof

Abstract

The present application relates to the technical field of paint, in particular to a pipeline inner wall anticorrosive paint and a preparation method thereof. The pipeline inner wall anticorrosive paint comprises a component A and a component B. The component A comprises organosilicon modified epoxy resin, inorganic silicon hybrid epoxy resin, active diluent, additive, bulk filler and functional filler. The component B comprises amine curing agent. The mass ratio of the organosilicon modified epoxy resin, the inorganic silicon hybrid epoxy resin, the active diluent, the bulk filler and the functional filler is (25-35):(10-25):(1-6):(20-30):(15-25). The paint has anticorrosive function at high temperature and excellent drag reduction performance, and has good impact resistance and wear resistance. The paint is applied to the pipeline inner wall protection, and plays a role of drag reduction and long-term corrosion prevention under high temperature use.

Description

TECHNICAL FIELD

[0001] The present application relates to the field of coating technology, in particular to a pipeline inner wall anticorrosive coating and a preparation method thereof. BACKGROUND

[0002] The crude oil and natural gas transported in the pipeline contain various corrosive pollutants, such as CO2, H2S, water, and microorganisms, which can cause corrosion inside the pipeline. The corrosion can be alleviated by using corrosion inhibitors, metal and non-metal liners or coatings.

[0003] However, the corrosion inhibitor has poor protection at high temperature, high consumption rate, and high price. The corrosion-resistant liner is expensive for long-distance pipeline engineering. Considering the natural gas transportation efficiency and the comprehensive effect of pipeline corrosion, the coating technology with excellent performance, both internal drag reduction and corrosion resistance, is a high-performance-price ratio technical solution.

[0004] With the deep exploitation of submarine natural gas and crude oil, the temperature of the transportation medium is getting higher and higher, and the medium is getting more and more complex. The existing pipeline internal drag reduction coating is mostly solvent-based coating, with thin single coating thickness. During the film forming process, pinholes are caused by the volatilization of the solvent, and the solvent is still left in the local thick coating. The coating has poor resistance to chemical substances such as carbon dioxide, hydrogen sulfide, phosphate synthetic oil, salt water, and heavy hydrocarbons, is relatively soft, has poor wear resistance, low adhesive strength, and often causes damage such as bubbling, cracking, and delamination of the pipeline internal drag reduction coating. Moreover, the currently developed coating is generally only suitable for use in a gas-liquid environment at room temperature to reduce drag, and is not suitable for use in a higher temperature environment. The coating cannot still maintain good temperature resistance, medium chemical resistance, wear resistance, adhesive strength, and gas-liquid pressure loss resistance in a high temperature environment.

[0005] A pipeline inner wall coating for oil field is disclosed in Chinese patent application No. CN201010501831.9, published on January 19, 2011. The coating of the first component is composed of trifluorochloroethylene-vinyl ether fluororesin 15-50 parts by weight, lubricating filler 8-30 parts by weight, dispersion aid 1-3 parts by weight, solvent 10-20 parts by weight, color paste 15-45 parts by weight, and lubricating aid 1-6 parts by weight. The color paste is composed of film-forming resin 40-80 parts by weight, dispersion aid 1-3 parts by weight, solvent 10-40 parts by weight, and pigment 2-40 parts by weight. The film-forming resin is three kinds of bisphenol A type epoxy resins E-20, E-12, and E-06, or trifluorochloroethylene-vinyl ether fluororesin. The second component is a curing agent, aromatic toluene diisocyanate addition product. The application contains solvent, which is not conducive to the drying of thick film pipeline inner wall and can easily cause defects, resulting in poor corrosion resistance and other properties. SUMMARY

[0006] To solve the problems of the existing pipeline inner wall anticorrosive coating mentioned in the background art, the present application provides a pipeline inner wall coating with good temperature resistance, medium chemical corrosion resistance, wear resistance and drag reduction performance, and the technical scheme is as follows:

[0007] The pipeline inner wall anticorrosive coating comprises a component A and a component B, the component A comprises organosilicon modified epoxy resin, inorganic silicon hybrid epoxy resin, active diluent, additive, bulk filler and functional filler; the component B comprises amine curing agent; the mass ratio of the organosilicon modified epoxy resin, the inorganic silicon hybrid epoxy resin, the active diluent, the bulk filler and the functional filler is (25-35):(10-25):(1-6):(20-30):(15-25).

[0008] In some embodiments, the preparation process of the inorganic silicon hybrid epoxy resin is as follows:

[0009] The ethyl silicate is dissolved in anhydrous ethanol and stirred uniformly at room temperature; hydrochloric acid aqueous solution is slowly added to the reaction system and stirred fully, and after the addition is completed, the reaction is carried out at room temperature for (20-40) min, then filtered and washed, and then added to the epoxy resin and 3-aminopropyl triethoxysilane and heated to (60-90) ℃ for reaction for (1-3) h, and then cooled to room temperature; wherein the mass ratio of the ethyl silicate, the anhydrous ethanol, the hydrochloric acid aqueous solution, the epoxy resin and the 3-aminopropyl triethoxysilane is (20-30):(20-30):(2-6):(20-30):(4-6); the mass concentration of the hydrochloric acid aqueous solution is 0.2-1.0%.

[0010] In some embodiments, the 3-aminopropyl triethoxysilane is KH-550; the epoxy resin is bisphenol F type resin; and in the preparation process of the inorganic silicon hybrid epoxy resin, the hydrochloric acid aqueous solution is added to the reaction system in a dropwise manner.

[0011] In some embodiments, the additive comprises dispersant, defoaming agent, leveling agent and thixotropic agent; the component A comprises organosilicon modified epoxy resin 25-35 parts, inorganic silicon hybrid epoxy resin 10-25 parts, active diluent 1-6 parts, dispersant 0.2-0.8 parts, defoaming agent 0.2-0.6 parts, leveling agent 0.4-0.8 parts, thixotropic agent 0.3-0.8 parts, bulk filler 20-30 parts and functional filler 15-25 parts by mass.

[0012] In some embodiments, the ratio of the epoxy equivalent in the organosilicon modified epoxy resin, the inorganic silicon hybrid epoxy resin and the active diluent in the component A to the active hydrogen equivalent in the amine curing agent in the component B is 1:1.

[0013] In some embodiments, the functional filler includes a rust-proof filler, a wear-resistant filler, a lubricating filler; the rust-proof filler is aluminum tripolyphosphate; the wear-resistant filler is one or more combinations of silicon carbide, silicon powder; the lubricating filler is molybdenum dioxide.

[0014] In some embodiments, the silicone-modified epoxy resin is one or more combinations of Shin-Etsu KR-2046, ES-1023, ES-100N, TY-H26; the active diluent is one or more combinations of 692, AGE, 501; the body filler is one or more combinations of titanium white powder, barite powder, feldspar powder, talc powder.

[0015] In some embodiments, the dispersant is one or more combinations of BYK110, BYK163, and Ucare 710s; the defoaming agent is one or more combinations of 6600, 6800, BYK A530, and Ucare 272s; the leveling agent is one or more combinations of BYK333, AFCONA3238, and Ucare Chemical 384s; the thixotropic agent is one or more combinations of fumed silica and polyamide wax thixotropic agent.

[0016] In some embodiments, the amine curing agent is one or more combinations of an alicyclic amine curing agent, a phenolic amide curing agent, and a polyamide curing agent.

[0017] The application also provides a preparation method of the pipeline inner wall anticorrosive coating.

[0018] Based on the above, compared with the prior art, the pipeline inner wall anticorrosive coating provided by the application has the following beneficial effects:

[0019] The pipeline inner wall anticorrosive coating provided by the application has high-temperature anticorrosive function and excellent drag reduction performance, and has good impact resistance and wear resistance, and is applied to pipeline inner wall protection, and plays a role of drag reduction and long-acting corrosion prevention in a high-temperature use state.

[0020] Other features and advantages of the application will be set forth in the following description, and in part will become apparent to those skilled in the art upon examination of the following or can be learned by practice of the application. The objects and other advantages of the application can be realized and attained by the structure and / or components particularly pointed out in the description and claims. DETAILED DESCRIPTION

[0021] In order to make the purposes, technical solutions and advantages of the embodiments of the present application clearer, the following will clearly and completely describe the technical solutions in the embodiments of the present application. Obviously, the described embodiments are only some but not all of the embodiments of the present application; as long as there is no conflict, the technical features in the different embodiments of the present application can be combined with each other; based on the embodiments in the present application, all other embodiments obtained by those of ordinary skill in the art without creative work fall into the protection scope of the present application.

[0022] In the description of the present application, it should be noted that all the terms (including technical terms and scientific terms) used in the present application have the same meanings as those commonly understood by those of ordinary skill in the art to which the present application belongs, and should not be understood as limiting the present application; it should be further understood that the terms used in the present application should be understood as having meanings consistent with the meanings of these terms in the context of the present specification and the related art, and should not be understood in an idealized or overly formal sense, except as expressly defined in the present application.

[0023] The present application provides a preparation method of a pipeline inner wall anticorrosive coating, which comprises the following steps:

[0024] The preparation method of the component A is as follows:

[0025] (1) adding silicone modified epoxy resin, inorganic silicon hybrid epoxy resin, active diluent, dispersant, defoaming agent and leveling agent into a dispersion cylinder, uniformly dispersing to obtain a mixture M;

[0026] (2) adding body filler and functional filler into the obtained mixture M and uniformly dispersing, and then adding thixotropic agent and uniformly dispersing, to obtain the component A.

[0027] After the preparation of the component A and the component B, when used, the component A and the component B are mixed uniformly at a ratio of 1:1 of the epoxy equivalent in the silicone modified epoxy resin, the inorganic silicon hybrid epoxy resin and the active diluent in the component A to the active hydrogen equivalent in the amine curing agent in the component B, and then the coating can be used.

[0028] The formula of the component A and the component B is as follows:

[0029] The component A comprises, by mass fraction, 25-35 parts of silicone modified epoxy resin, 10-25 parts of inorganic silicon hybrid epoxy resin, 1-6 parts of active diluent, 0.2-0.8 parts of dispersant, 0.2-0.6 parts of defoaming agent, 0.4-0.8 parts of leveling agent, 0.3-0.8 parts of thixotropic agent, 20-30 parts of body filler and 15-25 parts of functional filler; the component B comprises amine curing agent.

[0030] The inorganic silicon hybrid epoxy resin is self-made, and the preparation process is as follows:

[0031] Ethyl silicate (TEOS) is dissolved in anhydrous ethanol, and stirred uniformly at room temperature;

[0032] Hydrochloric acid aqueous solution is slowly added into the reaction system and stirred fully, after the addition is completed, the reaction is carried out at room temperature for (20-40) min, then filtered and washed, and then added into epoxy resin and 3-aminopropyl triethoxysilane, and heated to (60-90) ℃ and reacted for (1-3) h, and then cooled to room temperature.

[0033] The mass ratio of the ethyl silicate, the anhydrous ethanol, the hydrochloric acid aqueous solution, the epoxy resin, and the 3-aminopropyl triethoxysilane is (20-30) :(20-30) :(2-6) :(20-30) :(4-6); the mass concentration of the hydrochloric acid aqueous solution is 0.2-1.0%; and the epoxy resin is a bisphenol F type resin.

[0034] The application also provides the formula (unit: weight fraction) of the following examples and comparative examples, as shown in Tables 1-2:

[0035] Table 1

[0036]

[0037] Table 2

[0038]

[0039]

[0040] In Table 1-2, the selection of the specific components of the above examples and comparative examples is as follows:

[0041] The organic silicon modified epoxy resin is selected from KR-2046 of Shin-Etsu; the active diluent is selected from 692; the dispersant is selected from Optic 710s; the defoaming agent is selected from 6800; the leveling agent is selected from AFCONA3238; the thixotropic agent is selected from polyamide wax thixotropic agent Optima; the body filler is composed of titanium white powder, feldspar and barite powder at a mass ratio of 1:1:1; and the amine curing agent is selected from Kadelite LITE 3070.

[0042] The preparation process of the inorganic silicon hybrid epoxy resin is as follows:

[0043] Ethyl silicate (TEOS) is dissolved in a certain amount of anhydrous ethanol, stirred at room temperature for 10 min; an aqueous hydrochloric acid solution is slowly added to the system and stirred thoroughly, after the addition is completed, the reaction is carried out at room temperature for 30 min, then filtered and washed, and then epoxy resin Nanya NPEF-170 and 3-aminopropyl triethoxysilane KH-550 are added and mixed, and the mixture is heated to 70℃ and reacted for 2 h, and then cooled to room temperature. The mass ratio of the ethyl silicate, anhydrous ethanol, aqueous hydrochloric acid solution, epoxy resin, and 3-aminopropyl triethoxysilane is 20:30:3:20:4. The mass concentration of the aqueous hydrochloric acid solution is 0.5%.

[0044] In Table 1-2, in particular:

[0045] The functional fillers of the above Examples 1-3 and Comparative Examples 1-3 are composed of anti-rust fillers, wear-resistant fillers, and lubricating fillers in a mass ratio of 1:2:2;

[0046] The epoxy resin in Comparative Example 3 is Nanya NPEF-170;

[0047] The functional fillers of Comparative Example 4 are composed of anti-rust fillers and wear-resistant fillers in a mass ratio of 1:2;

[0048] The functional fillers of Comparative Example 5 are composed of wear-resistant fillers and lubricating fillers in a mass ratio of 2:2;

[0049] The functional fillers of Comparative Example 6 are composed of anti-rust fillers and lubricating fillers in a mass ratio of 1:2;

[0050] The anti-rust fillers are aluminum tripolyphosphate, the wear-resistant fillers are selected from silicon carbide, and the lubricating fillers are molybdenum dioxide;

[0051] According to the formulations in Table 1-2, the above examples and comparative examples are prepared into Group A components and Group B components according to the following preparation method:

[0052] (1) Resins (silicone-modified epoxy resin, inorganic silicon hybrid epoxy resin, and epoxy resin), active diluents, dispersants, defoamers, and leveling agents are added to a dispersion cylinder and dispersed uniformly to obtain a mixture M;

[0053] (2) The body fillers and functional fillers are added to the obtained mixture M and dispersed uniformly, and then the thixotropic agent is added and dispersed uniformly to obtain the Group A component.

[0054] The epoxy equivalent in the silicone-modified epoxy resin, inorganic silicon hybrid epoxy resin, and active diluent in the Group A component is matched with the active hydrogen equivalent in the amine curing agent in the Group B component at a ratio of 1:1.

[0055] The products prepared in the above examples and the products prepared in the comparative examples, the component A and the component B were mixed and used, and the following performance tests were carried out and the test results were obtained, as shown in Tables 3-4 below:

[0056] Table 3 Performance data of examples and comparative examples

[0057]

[0058]

[0059] Table 4 Performance data of examples and comparative examples

[0060]

[0061]

[0062] Among them, the main performance indicators of the pipeline inner wall anticorrosive coating provided by the application and the detection method thereof are shown in Table 5 below:

[0063] Table 5

[0064]

[0065] The data results of the examples and the comparative examples show that:

[0066] The difference between the comparative example 1 and the examples is that: it uses inorganic silicon hybrid epoxy resin to replace the organic silicon modified epoxy resin in the example 1, that is, the resin only uses inorganic silicon hybrid epoxy resin; compared with the example 1, the bending resistance, elongation at break of the comparative example 1 decreases, indicating that the toughness is poor, and the wear resistance is poor, the contact angle of the coating film with water decreases, indicating that the drag reduction effect is reduced, in addition, the adhesion is reduced and the liquid pressure loss resistance is poor.

[0067] The difference between the comparative example 2 and the examples is that: it uses organic silicon modified epoxy resin to replace the inorganic silicon hybrid epoxy resin in the example 1, that is, the resin only uses organic silicon modified epoxy resin; compared with the example 1, the wear resistance and the corrosion resistance under high temperature use of the comparative example 2 are poor, and the contact angle of the coating film with water decreases, indicating that the drag reduction effect is reduced.

[0068] The difference between the comparative example 3 and the examples is that: the resin uses organic silicon modified epoxy resin and unmodified bisphenol F type resin; compared with the example 1, the wear resistance and the corrosion resistance of the comparative example 3 are reduced, the corrosion resistance under high temperature use decreases, and the contact angle of the coating film with water decreases, indicating that the drag reduction effect is reduced.

[0069] Compared with the example 1, the wear resistance of the comparative example 4 decreases slightly, and the contact angle of the coating film with water decreases, indicating that the drag reduction effect is reduced.

[0070] Compared with Example 1, the corrosion resistance of Comparative Example 5 is poor.

[0071] Compared with Example 1, the wear resistance of Comparative Example 6 is poor.

[0072] The pipeline inner wall anticorrosive coating prepared by the embodiment of the present application has high-temperature anticorrosive function and excellent drag reduction performance, and has good impact resistance and wear resistance, and is applied to the pipeline inner wall protection, plays the role of drag reduction and long-acting corrosion resistance in the high-temperature use state.

[0073] The pipeline inner wall anticorrosive coating technical scheme provided by the present application comprises at least the following design concepts and beneficial effects:

[0074] (1) The present application scheme selects organic silicon epoxy resin and inorganic silicon hybrid epoxy resin, wherein the organic silicon epoxy resin has good high-temperature stability and low surface tension, the inorganic silicon epoxy resin increases the crosslinking density and blocks the penetration of chemical media, and the two have a synergistic effect, and have good high-temperature corrosion resistance.

[0075] (2) The present application selects organic silicon modified epoxy resin and inorganic silicon hybrid epoxy resin with good flexibility, wherein inorganic silicon is used as a crosslinking point, and cooperates with wear-resistant fillers to improve the wear resistance of the coating together, and the coating of the present application can reduce the frictional damage of impurities to the pipeline during transportation and prolong the service life of the pipeline.

[0076] (3) The organic silicon modified epoxy resin has low friction coefficient and low surface tension characteristics, and the coating film has a water contact angle > 90°, becoming a hydrophobic coating, and the lubricating filler is added in the coating system, so that when the coating of the present application is used as the inner wall coating of the oilfield pipeline, the flow resistance of the liquid in the pipeline can be reduced, and the effect of drag reduction and efficiency improvement can be achieved.

[0077] (4) The present application scheme selects organic silicon epoxy resin and inorganic silicon hybrid epoxy resin, wherein the inorganic silicon hybrid epoxy resin has balanced flexibility of bisphenol F type, reduces internal stress, and uses active diluent and solvent-free curing agent to reduce the influence of solvent, avoids thick film construction at one time, large internal stress, and internal solvent volatilization, and causes defects.

[0078] In summary, the pipeline inner wall anticorrosive coating prepared by the present application has high-temperature anticorrosive function and excellent drag reduction performance, and has good impact resistance and wear resistance, and is applied to the pipeline inner wall protection, plays the role of drag reduction and long-acting corrosion resistance in the high-temperature use state; and the preparation process of the coating provided by the present application is simple and has good construction performance.

[0079] It should be noted that:

[0080] The room temperature used in the specific implementation process herein is 15-35℃.

[0081] In this document, the expression "between ~ and ~" is used to indicate a range of values, and the expression includes the two end values.

[0082] The specific parameters or some common reagents in the above examples are specific embodiments or preferred embodiments under the concept of the present application, but not a limitation; those skilled in the art can make adaptive adjustment within the concept and protection scope of the present application. In addition, if not specifically stated, the raw materials used can be conventional commercial products in the art, or prepared by conventional methods in the art.

[0083] In addition, those skilled in the art should understand that although there are many problems in the prior art, each embodiment or technical solution of the present application can only be improved in one or several aspects, and it is not necessary to solve all the technical problems listed in the prior art or background art at the same time. Those skilled in the art should understand that what is not mentioned in a claim should not be regarded as a limitation of the claim.

[0084] Although the terms such as functional filler, curing agent, etc. are used more frequently in this document, the possibility of using other terms is not excluded. The use of these terms is only to facilitate the description and explanation of the essence of the present application; any additional limitation by interpreting them is contrary to the spirit of the present application; the terms "first", "second", etc. (if any) in the specification and claims of the embodiments of the present application are used to distinguish similar objects, and do not necessarily describe a specific order or sequence.

[0085] Finally, it should be pointed out that: the above embodiments are only used to illustrate the technical solutions of the present application, but not a limitation; although the present application has been described in detail with reference to the foregoing embodiments, those skilled in the art should understand that they can still modify the technical solutions recorded in the foregoing embodiments, or make equivalent replacement for part or all of the technical features; and these modifications or replacements do not make the essence of the corresponding technical solution deviate from the scope of the technical solutions of the embodiments of the present application.

Claims

1. A pipe inner wall anti-corrosion coating, comprising component A and component B, characterized in that: The first component includes organosilicon-modified epoxy resin, inorganic silicon hybrid epoxy resin, reactive diluent, additives, extender filler, and functional filler. Component B includes an amine curing agent; The mass ratio of the organosilicon-modified epoxy resin, inorganic silicon hybrid epoxy resin, reactive diluent, extender filler, and functional filler is (25-35):(10-25):(1-6):(20-30):(15-25); The preparation process of the inorganic silicon hybrid epoxy resin is as follows: Dissolve ethyl silicate in anhydrous ethanol and stir until homogeneous at room temperature; Slowly add hydrochloric acid aqueous solution to the reaction system and stir thoroughly. After the addition is complete, react at room temperature for (20-40) min, filter, wash, and then add to epoxy resin and 3-aminopropyltriethoxysilane. Heat to (60-90) °C and react for (1-3) h. Cool to room temperature to obtain the product; wherein the epoxy resin is bisphenol F type resin. The mass ratio of the ethyl silicate, anhydrous ethanol, hydrochloric acid aqueous solution, epoxy resin, and 3-aminopropyltriethoxysilane is (20-30):(20-30):(2-6):(20-30):(4-6). The mass concentration of the hydrochloric acid aqueous solution is 0.2%–1.0%; The functional fillers include rust-preventive fillers, wear-resistant fillers, and lubricating fillers; the rust-preventive filler is aluminum tripolyphosphate; the wear-resistant filler is one or more combinations of silicon carbide and silicon micro powder; and the lubricating filler is molybdenum dioxide.

2. The anti-corrosion coating for the inner wall of pipes according to claim 1, characterized in that: In the preparation of the inorganic silicon hybrid epoxy resin, the hydrochloric acid aqueous solution is added to the reaction system dropwise.

3. The anti-corrosion coating for the inner wall of pipes according to claim 1, characterized in that: The additives include dispersants, defoamers, leveling agents, and thixotropic agents; By weight, component A comprises 25-35 parts of organosilicon-modified epoxy resin, 10-25 parts of inorganic silicon hybrid epoxy resin, 1-6 parts of reactive diluent, 0.2-0.8 parts of dispersant, 0.2-0.6 parts of defoamer, 0.4-0.8 parts of leveling agent, 0.3-0.8 parts of thixotropic agent, 20-35 parts of extender filler, and 15-25 parts of functional filler.

4. The anti-corrosion coating for the inner wall of pipes according to claim 1, characterized in that: The ratio of epoxy equivalent in the organosilicon-modified epoxy resin, inorganic silicon hybrid epoxy resin, and reactive diluent in component A to the active hydrogen equivalent in the amine curing agent in component B is 1:

1.

5. The anti-corrosion coating for the inner wall of pipes according to claim 1, characterized in that: The organosilicon-modified epoxy resin is one or more combinations of Shin-Etsu KR-2046, ES-1023, and ES-100N; The reactive diluent is one or more combinations of 692, AGE, and 501; The filler material is one or more of titanium dioxide, barite powder, feldspar powder, and talc powder.

6. The anti-corrosion coating for the inner wall of pipes according to claim 3, characterized in that: The dispersant is one or more combinations of BYK110, BYK163, and Eucalyptus 710s; The defoamer is one or more of BYKA530 and Yoka272s; The leveling agent is one or a combination of BYK333, AFCONA3238, and Yoka Chemicals 384s; The thixotropic agent is one or more combinations of fumed silica and polyamide wax thixotropic agents.

7. The anti-corrosion coating for the inner wall of pipes according to claim 1, characterized in that: The amine curing agent is one or more combinations of alicyclic amine curing agents, phenolic amide curing agents, and polyamide curing agents.

8. A method for preparing a pipeline inner wall anti-corrosion coating according to claim 3, characterized in that, The preparation method of component A is as follows: Organosilicon-modified epoxy resin, inorganic silicon hybrid epoxy resin, reactive diluent, dispersant, defoamer, and leveling agent are dispersed evenly to obtain mixture M; extender filler and functional filler are added to mixture M and dispersed evenly, and then thixotropic agent is added and dispersed evenly to obtain component A. Mix component A and component B evenly to obtain the anti-corrosion coating for the inner wall of the pipe.

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