A graphene heavy-duty anticorrosive coating for oil pipes and a preparation method and application thereof

Abstract

The application discloses a graphene heavy-duty anticorrosive coating for oil pipes and a preparation method and application thereof, and belongs to the technical field of anticorrosive coatings.The graphene heavy-duty anticorrosive coating comprises component A and component B, the component A comprises epoxy resin, an organic solvent and graphene oxide, the component B comprises an organic solvent and a phenolic resin, and the mass fraction of the graphene oxide in the coating is 0.05wt%-0.6wt%.The preparation method specifically comprises the following steps: S1) preparing graphene oxide;S2) preparing epoxy resin;S3) respectively configuring the component A and the component B, then adding the component B into the component A, and stirring to obtain the coating.The coating has the advantages of less addition amount of graphene oxide, good dispersion, simple components, easy configuration and easy popularization and use.

Description

TECHNICAL FIELD

[0001] The application belongs to the technical field of anticorrosive coatings, and particularly relates to a graphene heavy-duty anticorrosive coating for oil pipes as well as a preparation method and application thereof. BACKGROUND

[0002] At present, the main pipeline steel in China is used for transporting oil and natural gas resources through long-distance pipelines. However, the buried pipeline will be corroded by the transported medium, which will reduce the wall thickness of the pipeline and thus reduce the strength of the pipeline and cause serious consequences. The methods for preventing metal corrosion mainly include improving the inherent corrosion resistance of metal materials, coating or plating a non-metallic or metallic protective layer, electrochemical protection, improving the corrosion environment or adding corrosion inhibitors or corrosion inhibitors to the medium. Among them, coating an organic non-metallic anticorrosive coating on the surface of the metal is the most easily implemented and effective protection measure so far. At present, solvent-based coatings are generally used for coating an anticorrosive coating on the surface of metal materials, but the VOC content is high, and even some heavy metals are contained, which leads to serious environmental pollution problems.

[0003] Patent CN109777253A discloses a graphene modified epoxy anticorrosive coating. The graphene modified epoxy anticorrosive coating is mainly prepared from component A and component B. Component A is mainly composed of epoxy resin, pigment, filler, additive and graphene dispersion liquid. Component B is phenolic resin. The mass ratio of the graphene dispersion liquid to component A is 6-12:100, and the mass ratio of component A to component B is 6-8:1. The graphene dispersion liquid is obtained by compounding graphene, mixed solvent and dispersant B. The mixed solvent is a mixture of dimethylbenzene, cyclohexanone, butanol, ethylene glycol ether and ethylene glycol ether acetate. The graphene is uniformly dispersed in the coating by using the mixed solvent, and the prepared coating has good stability and good corrosion resistance. However, the patent uses graphene and epoxy resin to prepare the anticorrosive coating, but the preparation process is complex, the connection between the graphene and the epoxy resin is poor, and it is difficult to meet the anticorrosive requirements of the oil and gas industry.

[0004] Patent CN110093087A discloses a two-component water-based graphene heavy anti-corrosion heat dissipation coating, which comprises an A component capable of curing into a film and a B component containing phenolic resin. The A component comprises, by weight percentage: graphene 0.5-1.5 wt%, epoxy resin emulsion 30-50 wt%, dispersing agent 0.5-2 wt%, silane coupling agent 0.5-2 wt%, anti-settling agent 1-2 wt%, defoaming agent 0.2-1 wt%, heat dissipation pigment 30-50 wt%, talc powder 6-12 wt%, precipitated barium sulfate 5-10 wt%, and deionized water 3-5 wt%. The B component comprises, by weight percentage: phenolic resin 10-30 wt%, zinc powder 40-70 wt%, phosphorus iron powder 10-20 wt%, anti-settling agent 1-2 wt%, and film-forming aid 5-10 wt%. The two-component water-based graphene heavy anti-corrosion heat dissipation coating can provide good corrosion protection for steel structures and improve heat dissipation efficiency. In addition, a preparation method of the two-component water-based graphene heavy anti-corrosion heat dissipation coating is also provided. However, the anti-corrosion coating provided by the patent has complex components and high configuration difficulty.

[0005] Patent CN109897518A discloses a solvent-free epoxy heavy anti-corrosion coating for underwater painting, which is composed of the following raw materials by weight: modified phenolic resin, epoxy resin, liquid polysulfide rubber, liquid coumarone resin, ester coupling agent, fumed silica, phenolic resin, diluent, toughening agent, adhesion promoter, wetting dispersant, defoaming agent, hydrophobic graphene, talc powder, titanium iron powder, red iron oxide, sericite, barium sulfate, and mica powder. The modified phenolic resin is composed of the following raw materials by weight: phenolic resin, diethylamine, dimethylbenzene, toluene diisocyanate, and 2-mercaptoethanol. The patent is an ecological and environmentally friendly type, non-VOC emission, non-toxic flame retardant, which can be directly painted on the surface of steel structures, concrete, wood, glass steel, etc. in fresh water or seawater, and meets the technical difficulties of underwater anti-corrosion of major equipment such as marine engineering, ocean-going ships, submarines, submarine pipelines, cross-sea bridges, port terminals, reservoir gates, etc. However, the patent provides a heavy anti-corrosion coating suitable for underwater corrosion prevention, which has complex components and high configuration difficulty.

[0006] Document (Preparation and Performance Research of Graphene Oxide Modified Waterborne Epoxy Anticorrosive Coatings, Anhui Chemical Industry, 2019, No. 2, 1-4) discloses that the waterborne epoxy resin emulsion is modified by using the hydrophilicity and corrosion resistance of graphene oxide, and graphene oxide modified waterborne epoxy anticorrosive coatings are prepared. The structure of graphene oxide is characterized by XPS and Raman spectrum, and the influence of the addition amount of graphene oxide and waterborne phenolic resin on the performance of the coating is discussed. The results show that when the addition amount of graphene oxide is 8% and the addition amount of epoxy phenolic resin is 50%, the graphene oxide modified waterborne epoxy anticorrosive coating prepared under the above conditions can well meet the established technical index. The paper discloses that the use of graphene oxide modified waterborne epoxy anticorrosive coating improves the mechanical properties, chemical properties and corrosion resistance of waterborne epoxy resin, but the addition amount of graphene is relatively large.

[0007] In summary, although various anticorrosive coatings are proposed in the prior art, it is still difficult to meet the increasingly improved anticorrosion requirements, and therefore there is still a need to develop anticorrosive coatings with better anticorrosion performance. SUMMARY

[0008] The present application provides a graphene heavy-duty anticorrosive coating for oil pipes and a preparation method and application thereof, which disperses and adds graphene subjected to surface oxidation treatment into phenolic epoxy resin to obtain a graphene heavy-duty anticorrosive coating for oil pipes. The labyrinth effect formed by the sheet structure of graphene oxide effectively blocks the transmission of water medium and oxygen in the coating, and forms an effective physical barrier effect, thereby achieving good anticorrosion effect.

[0009] To achieve the above-mentioned purposes, the technical solutions adopted by the present application are as follows:

[0010] Firstly, a graphene heavy-duty anticorrosive coating is provided, which comprises component A and component B. The component A comprises epoxy resin, organic solvent and graphene oxide, and the component B comprises organic solvent and phenolic resin. The mass fraction of graphene oxide in the graphene heavy-duty anticorrosive coating is 0.05wt% to 0.6wt%.

[0011] Further, the oxidation degree of graphene oxide is 30% to 35%.

[0012] Further, the component A comprises the following components by weight: epoxy resin 20 to 30 parts, organic solvent 30 to 40 parts, and graphene oxide 0.1 to 0.5 parts. The component B comprises the following components by weight: organic solvent 30 to 40 parts, and phenolic resin 15 to 20 parts.

[0013] Further, the organic solvent in component A is one or more of butanol, methyl ethyl ketone, cyclohexanone and ether alcohol, and the organic solvent in component B is one or more of THF, dioxane and DMSO.

[0014] Secondly, the application provides a preparation method of the graphene heavy-duty anticorrosive paint, which comprises the following steps:

[0015] S1) preparing graphene oxide;

[0016] S2) preparing epoxy resin;

[0017] S3) respectively preparing component A and component B, then adding component B into component A and stirring to obtain the paint.

[0018] Further, the preparation of the graphene oxide comprises the following steps: adding graphene into deionized water, stirring and ultrasonic dispersing for 2-3 hours; then adding concentrated acid, stirring and mixing uniformly, heating to 80-100 DEG C and ultrasonic treating for 0.5-1.5 hours, centrifuging, washing and drying to obtain graphene oxide.

[0019] Further, the concentrated acid is an acid with oxidizability, such as concentrated sulfuric acid or concentrated nitric acid; the adding amount is 10%-20% of the total amount of the reagents.

[0020] Further, the preparation of the epoxy resin comprises the following steps: taking bisphenol A and epoxy chloropropane with a mass ratio of 1:1.5-4, stirring and mixing uniformly, heating to 75-90 DEG C, adding alkali solution dropwise and reacting for 3-8 hours to obtain epoxy resin.

[0021] Further, the alkali solution is sodium hydroxide solution or potassium hydroxide solution with a concentration of 10-12%; the adding amount is 3-7% of the total amount of the reagents.

[0022] Further, the preparation of component A comprises the following steps: adding graphene oxide into organic solvent, stirring and ultrasonic dispersing for 10-40 minutes; then adding epoxy resin to obtain component A.

[0023] Finally, the application provides the application of the graphene heavy-duty anticorrosive paint or the graphene heavy-duty anticorrosive paint prepared by the preparation method in oil pipe anticorrosive paint.

[0024] In some specific embodiments, the preparation method of the graphene heavy-duty anticorrosive paint comprises the following steps:

[0025] S1) preparing graphene oxide;

[0026] The preparation of the graphene oxide specifically comprises the following steps: adding powdered graphene into deionized water, stirring and ultrasonic dispersing; then adding concentrated acid, stirring and mixing uniformly, heating and ultrasonic treating, centrifuging, washing and drying to obtain graphene oxide.

[0027] S2) preparing epoxy resin;

[0028] The preparation of the epoxy resin specifically comprises: stirring and mixing bisphenol A and epichlorohydrin, then heating to 75-90 DEG C, slowly adding 10-12% alkali solution, and reacting for 3-8 hours to obtain the epoxy resin.

[0029] S3) adding graphene oxide into an organic solvent, stirring and ultrasonic dispersion for 10-40 min; then adding the epoxy resin to obtain component A; then preparing component B, and then adding component B into component A and stirring to obtain the coating A.

[0030] The percentage content of the solution appearing in the present text is mass fraction.

[0031] Compared with the prior art, the present application has the following beneficial effects:

[0032] (1) The preparation method provided by the present application adds the graphene oxide dispersed after surface oxidation treatment into the phenolic epoxy resin to obtain the graphene heavy anti-corrosion oil pipe coating, the labyrinth effect formed by the thin sheet structure of the graphene oxide effectively blocks the transmission of the water medium and oxygen in the coating, forms an effective physical barrier effect, and achieves good anti-corrosion effect;

[0033] (2) In the preparation method, the graphene oxide is first added into the epoxy resin, the pores on the surface of the epoxy resin are improved, the shielding property is improved, the penetration of oxygen and water molecules is prevented, and the anti-corrosion effect of the coating is improved; meanwhile, the graphene oxide is embedded into the interior of the epoxy phenolic resin to form a multi-layer structure; and the layered graphene oxide is separated by the epoxy phenolic resin, and the conductivity of the graphene oxide is blocked;

[0034] (3) The graphene heavy anti-corrosion coating for oil pipes provided by the present application has the advantages of small addition amount of graphene oxide, good dispersion, simple composition, easy preparation, and easy popularization and use. DETAILED DESCRIPTION

[0035] It should be noted that the raw materials used in the present application are all ordinary commercially available products, and the source thereof is not specifically limited.

[0036] Example 1

[0037] A graphene heavy anti-corrosion coating for oil pipes has the following formula: the raw materials of component A are as follows in terms of mass component: epoxy resin 20 parts, butanol 30 parts, and 0.1 part of graphene oxide; the raw materials of component B are as follows in terms of mass component: THF 30 parts and phenolic resin 15 parts.

[0038] The coating is prepared by the following method:

[0039] S1) preparing graphene oxide;

[0040] The preparation of the graphene oxide specifically includes: adding powdered graphene into deionized water, stirring and ultrasonic dispersion for 2h; then adding concentrated sulfuric acid, stirring and mixing uniformly, heating to 80℃, and ultrasonic dispersion for 1.5h, centrifugal washing and drying to obtain graphene oxide; the mass ratio of graphene, water and concentrated sulfuric acid is 1:10:2.

[0041] S2) preparing an epoxy resin;

[0042] The preparation of the epoxy resin specifically includes: taking bisphenol A and epichlorohydrin at a mass ratio of 1:1.5, stirring and mixing, heating to 75℃, and slowly adding 12% sodium hydroxide solution, the amount of the sodium hydroxide solution accounts for 10% of the total amount of the reagents, and reacting for 8h to obtain the epoxy resin.

[0043] S3) adding graphene oxide into butanol, stirring and ultrasonic dispersion for 10min; then adding the epoxy resin to obtain component A; then preparing component B, and then adding component B into component A, and stirring to obtain coating A.

[0044] Example 2

[0045] A graphene heavy-duty anticorrosive coating for oil pipes, the formula of which is: the raw materials of component A are epoxy resin 25 parts, methyl ethyl ketone 35 parts, and 0.3 parts of graphene oxide; the raw materials of component B are dioxane 36 parts and phenolic resin 17 parts.

[0046] The coating is prepared by the following method:

[0047] S1) preparing graphene oxide;

[0048] The preparation of the graphene oxide specifically includes: adding powdered graphene into deionized water, stirring and ultrasonic dispersion for 3h; then adding concentrated sulfuric acid, stirring and mixing uniformly, heating to 100℃, and ultrasonic dispersion for 0.5h, centrifugal washing and drying to obtain graphene oxide; the mass ratio of graphene, water and concentrated sulfuric acid is 1:10:2.

[0049] S2) preparing an epoxy resin;

[0050] The preparation of the epoxy resin specifically includes: taking bisphenol A and epichlorohydrin at a mass ratio of 1:4, stirring and mixing, heating to 90℃, and slowly adding 10% sodium hydroxide solution, the amount of the sodium hydroxide solution accounts for 20% of the total amount of the reagents, and reacting for 3h to obtain the epoxy resin.

[0051] S3) adding graphene oxide into methyl ethyl ketone, stirring and ultrasonic dispersion for 40min; then adding the epoxy resin to obtain component A; then preparing component B, and then adding component B into component A, and stirring to obtain coating B.

[0052] Example 3

[0053] A graphene heavy-duty coating for oil pipe, the formula is: the raw materials of component A are as follows in mass fraction: epoxy resin 30 parts, butanol 40 parts, 0.5 parts of graphene oxide; the raw materials of component B are as follows in mass fraction: THF 40 parts, phenolic resin 20 parts.

[0054] The coating is prepared by the following method:

[0055] S1) preparing graphene oxide;

[0056] The preparation of the graphene oxide specifically comprises: adding powdered graphene into deionized water, stirring and ultrasonic dispersion for 2.5 h; then adding concentrated sulfuric acid, stirring and mixing uniformly, heating to 85℃, and ultrasonic for 1 h, centrifugal washing and drying to obtain graphene oxide; the mass ratio of graphene, water and concentrated sulfuric acid is 1:10:2.

[0057] S2) preparing epoxy resin;

[0058] The preparation of the epoxy resin specifically comprises: taking bisphenol A and epichlorohydrin in a mass ratio of 1:2.5, stirring and mixing, heating to 80℃, and slowly adding 11% sodium hydroxide solution, the amount of the sodium hydroxide solution added accounts for 15% of the total amount of the reagents, and the reaction is carried out for 5 h to obtain the epoxy resin.

[0059] S3) adding graphene oxide into butanol, stirring and ultrasonic dispersion for 30 min; then adding epoxy resin to obtain component A; then preparing component B, and then adding component B into component A, and stirring to obtain coating C.

[0060] Example 4

[0061] The difference from example 3 is that the formula of the coating is: the raw materials of component A are as follows in mass fraction: epoxy resin 32 parts, butanol 28 parts, 0.6 parts of graphene oxide; the raw materials of component B are as follows in mass fraction: THF 36 parts, phenolic resin 17 parts. Finally, coating D is obtained.

[0062] Example 5

[0063] The difference from example 3 is that the formula of the coating is: the raw materials of component A are as follows in mass fraction: epoxy resin 25 parts, butanol 35 parts, 0.3 parts of graphene oxide; the raw materials of component B are as follows in mass fraction: THF 28 parts, phenolic resin 22 parts. Finally, coating E is obtained.

[0064] Example 6

[0065] The difference from Example 3 is that the mass ratio of bisphenol A and epichlorohydrin in step S2) is 1:4.5 (the total amount of both is unchanged). Finally, coating F is obtained.

[0066] Experimental Example

[0067] The above prepared coatings A-F are respectively coated on metal plates, and after curing, a coating layer with a thickness of 0.5 mm is formed, and the water absorption, corrosion voltage, corrosion rate, and corrosion prevention efficiency are measured, and the test results are shown in Table 1.

[0068] Table 1

[0069] No. Water absorption (%) Corrosion voltage (mV) Corrosion rate (mm / year) Efficiency of corrosion protection (%) Coating A 2.1 -311 4.07 x 10 -4 ]] 97.2 Coating B 2.3 -298 4.11 x 10 -4 ]] 96.9 Coating C 1.9 -279 3.79 x 10 -4 ]] 97.4 Coating D 2.9 -345 4.68 x 10 -4 ]] 85.1 Coating E 2.7 -331 4.49 x 10 -4 ]] 87.3 Coating F 2.8 -337 4.54 x 10 -4 ]]> 85.8

[0070] Finally, it should be noted that the above content is only used to illustrate the technical solutions of the present application, and is not a limitation on the protection scope of the present application. Simple modifications or equivalent replacements of the technical solutions of the present application made by those skilled in the art do not deviate from the essence and scope of the technical solutions of the present application.

Claims

1. A graphene heavy-duty anticorrosive coating, characterized by, For component A and component B, the component A is the following components in parts by weight: epoxy resin 20~30 parts, organic solvent 30~40 parts, graphene oxide 0.1~0.5 parts; the component B is the following components in parts by weight: organic solvent 30~40 parts, phenolic resin 15~20 parts; The organic solvent in component A is one or more of butanol, methyl ethyl ketone, cyclohexanone and ether alcohol; The organic solvent in component B is one or more of THF, dioxane and DMSO; The preparation method of the graphene heavy-duty anticorrosive coating comprises the following steps: S1) preparing graphene oxide; S2) preparing epoxy resin; S3) respectively configuring component A and component B, then adding component B into component A and stirring to obtain the coating; The preparation steps of the epoxy resin are as follows: taking bisphenol A and epichlorohydrin in a mass ratio of 1:1.5~4, stirring uniformly, heating to 75~90℃, and adding alkali solution dropwise, and reacting for 3~8h to obtain the epoxy resin.

2. The graphene heavy-duty anticorrosive paint according to claim 1, characterized in that, The oxidation degree of the graphene oxide is 30~35%.

3. The method for preparing the graphene heavy-duty anticorrosive coating according to any one of claims 1-2, characterized in that, Comprising the following steps: S1) preparing graphene oxide; S2) preparing epoxy resin; S3) respectively configuring component A and component B, then adding component B into component A and stirring to obtain the coating; The preparation steps of the epoxy resin are as follows: taking bisphenol A and epichlorohydrin in a mass ratio of 1:1.5~4, stirring uniformly, heating to 75~90℃, and adding alkali solution dropwise, and reacting for 3~8h to obtain the epoxy resin.

4. The production method according to claim 3, characterized by, The preparation steps of the graphene oxide are as follows: adding graphene into deionized water, stirring and ultrasonicating for 2~3h; then adding concentrated acid, stirring uniformly, heating to 80~100℃, and ultrasonicating for 0.5~1.5h, and then centrifuging, washing and drying to obtain the graphene oxide.

5. The production method according to claim 4, characterized by, The preparation steps of the component A are as follows: adding graphene oxide into organic solvent, stirring and ultrasonicating for 10~40min; then adding epoxy resin to obtain component A.

6. The graphene heavy-duty anticorrosive coating of any one of claims 1-2 or the graphene heavy-duty anticorrosive coating obtained by the preparation method of any one of claims 3-5 is applied to anticorrosive coating for oil pipes.