Powder coating applied to pipeline protection and preparation method thereof
By introducing functionalized epoxy resin components and modified fillers into epoxy powder coatings, and utilizing the synergistic effect of hindered amine structures and pyrimidine rings, the problem of insufficient weather resistance and waterproofing of epoxy powder coatings is solved, achieving high weather resistance and waterproofing of the coatings.
Patent Information
- Authority / Receiving Office
- CN · China
- Patent Type
- Applications(China)
- Current Assignee / Owner
- Filing Date
- 2026-01-16
- Publication Date
- 2026-04-07
AI Technical Summary
Existing epoxy powder coatings have insufficient weather resistance and waterproofing during use. Conventional additives are prone to migration, affecting coating performance and resulting in poor waterproofing.
The coating employs functionalized epoxy resin components and modified fillers. The functionalized epoxy resin components contain hindered amine structures and pyrimidine rings, while the modified fillers form nano-silica structures and unsaturated double bonds through nucleophilic substitution reactions, synergistically improving the coating's weather resistance and water resistance.
It significantly improves the weather resistance and water resistance of powder coatings, enhances mechanical properties, and solves the problem of damage to epoxy powder coatings under external stimuli.
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Abstract
Description
TECHNICAL FIELD
[0001] The present application relates to the technical field of powder coating preparation, more particularly, it relates to a powder coating applied to pipeline protection and a preparation method thereof. BACKGROUND
[0002] Epoxy powder coating has a wide application in the field of pipeline protection due to its advantages such as good corrosion resistance, high adhesion, excellent mechanical properties and convenient construction.
[0003] However, the epoxy powder coating is inevitably affected by external stimuli such as heat, mechanical, chemical and ultraviolet radiation during use, which causes local damage or microcrack expansion in the epoxy resin, affecting the comprehensive performance of the epoxy powder coating. In the prior art, antioxidants, ultraviolet absorbers and other additives are often added to improve the weather resistance, but the molecular weight of the conventional antioxidants and ultraviolet absorbers is small, they cannot participate in the curing reaction, and they are easy to migrate and precipitate, resulting in poor weather resistance of the epoxy powder coating, and the existing epoxy powder coating has poor waterproof performance, and the corrosion medium such as water molecules can easily enter the inside of the coating film and corrode the pipeline material.
[0004] Based on the above statement, the present application provides a powder coating applied to pipeline protection with good mechanical properties, good weather resistance and excellent waterproof performance. SUMMARY
[0005] In order to solve the problems mentioned in the background art, the present application provides a powder coating applied to pipeline protection and a preparation method thereof.
[0006] A powder coating applied to pipeline protection comprises the following raw materials by weight: 40-50 parts of functionalized epoxy resin component, 15-25 parts of silicone resin, 20-30 parts of phenolic resin, 5-7 parts of diluent, 5-10 parts of leveling agent, 15-25 parts of modified filler, 1.4-1.8 parts of accelerator, 18-20 parts of curing agent and 0.3-0.5 parts of photoinitiator.
[0007] The functionalized epoxy resin component is first prepared by ring-opening reaction of 4,6-diamino-2-mercapto pyrimidine and 4-hydroxy phthalic anhydride to obtain a carboxyl monomer, then by amidation reaction of 4-aminopiperidine to obtain a piperidyl compound, and finally by nucleophilic substitution reaction of epoxy chloropropane.
[0008] The modified filler is first prepared by treating mica powder with hydrochloric acid aqueous solution to obtain pretreated mica powder, then by hydrolysis coating of tetraethyl orthosilicate to obtain core-shell particles, then by modification of KH-560 to obtain epoxy core-shell particles, and finally by nucleophilic substitution reaction of 4-vinyl benzyl chloride.
[0009] The application discloses a preparation method of a powder coating applied to pipeline protection.
[0010] Step S1, uniformly mixing a functional epoxy resin component, a silicon resin, a phenolic resin, a diluent and a leveling agent, vacuum degassing to prepare component A;
[0011] Step S2, uniformly mixing a modified filler, an accelerator, a curing agent and a photoinitiator to prepare component B;
[0012] Step S3, uniformly mixing component A and component B, irradiating under ultraviolet light for 14-18 min, then extruding through a double-screw extruder, crushing, sieving to obtain the powder coating applied to pipeline protection.
[0013] Further, the diluent is butyl glycidyl ether or 1,4-butanediol diglycidyl ether.
[0014] Further, the leveling agent is BYK-329 or TEGO 1484.
[0015] Further, the accelerator is 2,4,6-tris(dimethylaminomethyl)phenol or 2-ethyl-4-methylimidazole.
[0016] Further, the curing agent is diethylenetriamine or polyetheramine D230.
[0017] Further, the photoinitiator is 2,4,6-trimethylbenzoyl-diphenyl phosphine oxide.
[0018] Further, the wavelength peak of the ultraviolet light irradiation is 365 nm, and the intensity is 80 mW / cm 2 .
[0019] Further, the extrusion process of the double-screw extruder is as follows: 80-100 DEG C in a first zone, 105-120 DEG C in a second zone, 100-110 DEG C in a third zone, 95-105 DEG C in a fourth zone, 100-105 DEG C in a fifth zone, a die temperature of 105 DEG C and a screw rotation speed of 200 rpm.
[0020] Further, the functional epoxy resin component is prepared by the following steps:
[0021] Step A1, 4, 6-diamino-2-mercapto pyrimidine, 4-hydroxy phthalic anhydride and tetrabutyl ammonium bromide were added into anhydrous THF, stirred uniformly, heated to reflux temperature, stirred for 12-16 h, cooled to room temperature, rotary evaporation, to obtain the carboxyl monomer. During the above reaction process, the amino group of 4, 6-diamino-2-mercapto pyrimidine can undergo ring-opening reaction with the acid anhydride group of 4-hydroxy phthalic anhydride to obtain the carboxyl monomer. During the reaction process, the amount of substance of 4, 6-diamino-2-mercapto pyrimidine is slightly higher than that of 4-hydroxy phthalic anhydride, so that there are still remaining amino groups after the reaction to participate in the subsequent reaction process;
[0022] Step A2, the carboxyl monomer was added into anhydrous DMF, stirred uniformly, and the mixed solution a of N, N-dicyclohexyl carbodiimide, 4-dimethyl amino pyridine, 4-amino piperidine and anhydrous DMF was added dropwise, after dropping, heated to 78-82℃, stirred for 3.2-3.6 h, centrifuged, washed, dried, to obtain the piperidyl compound. During the above reaction process, the carboxyl group of the carboxyl monomer can undergo amide reaction with the amino group of the amino pyridine to obtain the piperidyl compound.
[0023] Step A3, the piperidyl compound and triethylamine were added into anhydrous DMF, heated to 40-50℃, stirred uniformly, and epichlorohydrin was added dropwise, after dropping, heated to 64-70℃, stirred for 4.6-5.4 h, reduced pressure distillation, to obtain the functional epoxy resin component. The active amino group of the piperidyl compound undergoes nucleophilic substitution reaction with the chlorine atom of epichlorohydrin to obtain the functional epoxy resin component.
[0024] Further, in the step A1, the mass ratio of 4, 6-diamino-2-mercapto pyrimidine, 4-hydroxy phthalic anhydride, tetrabutyl ammonium bromide and anhydrous THF is 1-2:1.1-2.2:0.02-0.04:40-50.
[0025] Further, in the step A2, the mass ratio of the carboxyl monomer, anhydrous DMF and the mixed solution a is 3-4:40-50:20-30, and the mass ratio of N, N-dicyclohexyl carbodiimide, 4-dimethyl amino pyridine, 4-amino piperidine and anhydrous DMF in the mixed solution a is 2.6-3.2:1.4-1.8:1-1.4:15.
[0026] Further, in the step A3, the mass ratio of the piperidyl compound, triethylamine, anhydrous DMF and epichlorohydrin is 1.6-2.4:0.02-0.04:50-60:0.4-0.58.
[0027] Further, the modified filler is prepared by the following steps:
[0028] Step B1, mica powder is added into hydrochloric acid aqueous solution for acid pickling treatment, filtered, washed, dried, crushed, sieved, and pretreated mica powder is obtained; the pretreated mica powder is added into ethanol aqueous solution, stirred uniformly, the pH value is adjusted to 8.6-9.2, tetraethyl orthosilicate is added, the temperature is raised to 58-64℃, and stirring is continued for 5-8h; after the reaction is completed, the pH value is adjusted to neutral, centrifuged, washed, dried, and calcined, and core-shell particles are obtained; in the above reaction process, the mica powder is first subjected to acid pickling treatment to expose abundant active hydroxyl groups on the surface, and then the surface is coated with tetraethyl orthosilicate as a silicon source to obtain core-shell particles;
[0029] Step B2, the core-shell particles, deionized water, anhydrous ethanol and KH-560 are ultrasonically mixed uniformly, the temperature is raised to 50-56℃, and stirring is continued for 5.4-6h; centrifuged, washed, and dried, and epoxidized core-shell particles are obtained; the epoxidized core-shell particles and anhydrous DMF are ultrasonically dispersed uniformly, and a mixed solution b of triethylamine, 4-vinylbenzyl chloride and anhydrous DMF is added dropwise; after the dropwise addition is completed, the temperature is raised to 88-92℃, and stirring reaction is carried out for 2.2-2.8h; centrifuged, washed, and dried, and a modified filler is obtained; first, the core-shell particles are treated with KH-560 to obtain epoxidized core-shell particles, and then nucleophilic substitution reaction occurs between the active chlorine atoms on the 4-vinylbenzyl chloride and the epoxidized core-shell particles to obtain the modified filler.
[0030] Further, in step B1, the specific process parameters for acid pickling are as follows: the mass fraction of hydrochloric acid aqueous solution is 8-12%, the acid pickling temperature is 45-55℃, and the acid pickling time is 0.6-0.9h.
[0031] Further, in step B1, the mass fraction of the ethanol aqueous solution is 16-20%.
[0032] Further, in step B1, the mass ratio of mica powder to hydrochloric acid aqueous solution is 1:30-40, and the mass ratio of pretreated mica powder, ethanol aqueous solution and tetraethyl orthosilicate is 0.6-0.8:60-80:0.46-0.52.
[0033] Further, in step B1, the calcination temperature is 1100-1300℃, and the calcination time is 2.2-2.4h.
[0034] Further, in step B2, the mass ratio of core-shell particles, deionized water, anhydrous ethanol and KH-560 is 2.4-3.2:10-16:20-30:0.14-0.2; the mass ratio of epoxidized core-shell particles, anhydrous DMF and mixed solution b is 0.8-1.2:40-50:16, and in the mixed solution b, the mass ratio of triethylamine, 4-vinylbenzyl chloride and anhydrous DMF is 0.02-0.06:0.18-0.22:10.
[0035] Compared with the prior art, the present application has the following beneficial effects:
[0036] In order to improve the weather resistance, water resistance and mechanical properties of the powder coating applied to pipeline protection, the present application proceeds from two aspects, one is to add a functional epoxy resin component in the raw material, the functional epoxy resin component contains a hindered amine structure, a hindered phenol structure and a pyrimidine ring, the hindered amine structure can not only inhibit the polymer photo-oxidative degradation through multiple mechanisms such as free radical capture, hydrogen peroxide decomposition and cyclic regeneration, but also can produce a synergistic effect with the hindered phenol structure having a rigid ring, so as to improve the weather resistance, mechanical properties and water resistance of the powder coating, and the pyrimidine ring not only has a rigid ring structure, but also can form a hydrogen bond with the active hydroxyl group on the modified filler, so as to further improve the weather resistance, water resistance and mechanical properties of the powder coating; the other is to add a modified filler, the modified filler is prepared by a nucleophilic substitution reaction of an epoxidized core-shell particle and 4-vinylbenzyl chloride, the outer layer of the modified filler contains a nano-silica structure, an unsaturated double bond and a hydrophobic benzene ring structure, and the inner core contains pretreated mica powder, the modified filler has the nano-silica structure and the unsaturated double bond, the nano-silica structure and the pretreated mica powder can fill the small defects in the coating, so as to improve the mechanical properties of the powder coating, and the presence of the unsaturated double bond can be chemically bonded with the mercapto group on the functional epoxy resin component, and through the synergistic effect of the above structures, the weather resistance, water resistance and mechanical properties of the coating are synergistically improved. DETAILED DESCRIPTION
[0037] In order to make the embodiments of the present application easier to understand, the present application will be described in detail below in combination with specific examples, which only serve to illustrate the present application and are not limited to the application range of the present application.
[0038] Sodium carbonate-sodium bicarbonate buffer solution was purchased from Shanghai Yuan Ye Biological Technology Co., Ltd., and the pH was 9.79; the silicone resin was purchased from Hubei Longsheng Four Seas New Material Co., Ltd., and the brand was SH-3040; the phenolic resin was purchased from Wuhan Lanya Pharmaceutical Chemical Co., Ltd., and the CAS number was 9003-35-4; the mica powder was purchased from Lingshou Baofeng Mica Processing Co., Ltd.; 2-ethyl-4-methylimidazole was purchased from Shandong Guohua Chemical Co., Ltd., and the CAS number was 931-36-2; polyetheramine D230 was purchased from Jinan Yunuo Chemical Co., Ltd., and the CAS number was 9046-10-0; 2, 4, 6-trimethylbenzoyl-diphenylphosphine oxide was purchased from Guangdong Chengshou New Material Co., Ltd., and the CAS number was 75980-60-8; butyl glycidyl ether, 1, 4-butanediol diglycidyl ether and diethylenetriamine were all purchased from Aladdin Reagent Network; 2, 4, 6-tris (dimethylaminomethyl) phenol was purchased from Jiangsu Lein Environmental Protection Technology Co., Ltd., and the CAS number was 90-72-2.
[0039] The application will be further described in detail in connection with the following examples and comparative examples.
[0040] Examples 1-3 and Comparative Examples 1-4 provide a powder coating applied to pipeline protection and a preparation method thereof.
[0041] Example 1
[0042] The example provides a powder coating applied to pipeline protection, comprising the following raw materials by weight: 40 parts of a functionalized epoxy resin component, 15 parts of a silicone resin, 20 parts of a phenolic resin, 5 parts of butyl glycidyl ether, 5 parts of BYK-329, 15 parts of a modified filler, 1.4 parts of 2,4,6-tris(dimethylaminomethyl)phenol, 18 parts of diethylenetriamine, and 0.3 parts of 2,4,6-trimethylbenzoyl-diphenylphosphine oxide.
[0043] A preparation method of a powder coating applied to pipeline protection, comprising the following steps:
[0044] Step S1, mixing the functionalized epoxy resin component, the silicone resin, the phenolic resin, the butyl glycidyl ether, and the BYK-329 at a rotation speed of 450 rpm for 14 min until uniform, controlling the temperature to be 50℃, and vacuum degassing at a vacuum degree of 0.6 kPa for 30 min to prepare component A;
[0045] Step S2, mixing the modified filler, the 2,4,6-tris(dimethylaminomethyl)phenol, the diethylenetriamine, and the 2,4,6-trimethylbenzoyl-diphenylphosphine oxide at a rotation speed of 500 rpm for 10 min until uniform to prepare component B;
[0046] Step S3, stirring component A and component B at a rotation speed of 560 rpm for 16 min until uniform, then placing under ultraviolet light with a wavelength of 365 nm and an intensity of 80 mW / cm 2 to irradiate for 14 min, then extruding through a twin-screw extruder, crushing, passing through a 140-mesh sieve to obtain the powder coating applied to pipeline protection; wherein the extrusion process of the twin-screw extruder is: zone 1 80℃, zone 2 105℃, zone 3 100℃, zone 4 95℃, zone 5 100℃, die temperature 105℃, screw rotation speed 200 rpm;
[0047] The functionalized epoxy resin component is prepared by the following steps:
[0048] Step A1, the carboxyl monomer was added into anhydrous THF, stirring was carried out at a rotation speed of 500 rpm for 12 min until uniform, the temperature was raised to reflux temperature, the rotation speed was kept unchanged, stirring was carried out for 12 h, the temperature was lowered to room temperature, rotary evaporation was carried out, the rotary evaporation temperature was controlled at 44 ℃, and rotary evaporation was carried out until the anhydrous THF was removed, thereby obtaining the carboxyl monomer, wherein the mass ratio of 4, 6-diamino-2-mercapto pyrimidine, 4-hydroxy phthalic anhydride, tetrabutylammonium bromide and anhydrous THF was 1:1.1:0.02:40;
[0049] Step A2, the carboxyl monomer was added into anhydrous DMF, stirring was carried out at a rotation speed of 560 rpm for 16 min until uniform, the mixture liquid a of N, N-dicyclohexyl carbodiimide, 4-dimethyl amino pyridine, 4-amino piperidine and anhydrous DMF was added dropwise, the dropwise addition was completed within 15 min, the dropwise addition rate was controlled at 3 drops / s, after the dropwise addition was completed, the temperature was raised to 78 ℃, the rotation speed was kept unchanged, and stirring was continuously carried out for 3.2 h, centrifugation was carried out at a rotation speed of 7000 rpm for 12 min, and then washing was sequentially carried out with anhydrous ethanol and deionized water for 3 times (the mass of anhydrous ethanol and deionized water was 15% of the mass of anhydrous DMF), and drying was carried out at 64 ℃ until the weight was constant, thereby obtaining the piperidyl compound, wherein the mass ratio of the carboxyl monomer, anhydrous DMF and the mixture liquid a was 3:40:20, and the mass ratio of N, N-dicyclohexyl carbodiimide, 4-dimethyl amino pyridine, 4-amino piperidine and anhydrous DMF in the mixture liquid a was 2.6:1.4:1:15;
[0050] Step A3, the piperidyl compound and triethylamine were added into anhydrous DMF, the temperature was raised to 40 ℃, stirring was carried out at a rotation speed of 560 rpm for 16 min until uniform, epichlorohydrin was added dropwise, the dropwise addition was completed within 10 min, the dropwise addition rate was controlled at 3 drops / s, after the dropwise addition was completed, the temperature was raised to 64 ℃, the rotation speed was kept unchanged, and stirring was continuously carried out for 4.6 h, anhydrous DMF was removed by distillation under reduced pressure, the distillation under reduced pressure was carried out at a temperature of 76 ℃ and a vacuum degree of 4.8 kPa, thereby obtaining the functionalized epoxy resin component, wherein the mass ratio of the piperidyl compound, triethylamine, anhydrous DMF and epichlorohydrin was 1.6:0.02:50:0.4;
[0051] The modified filler was prepared by the following steps:
[0052] Step B1, mica powder was added into hydrochloric acid aqueous solution, and acid pickling treatment was carried out, then the mixture was filtered, and the mica powder was washed with anhydrous ethanol and deionized water for 3 times respectively (the mass of anhydrous ethanol and deionized water was 15% of the mass of hydrochloric acid aqueous solution), and then the mica powder was dried at 58℃, crushed, and sieved through a 400 mesh screen to obtain pretreated mica powder; the pretreated mica powder was added into an ethanol aqueous solution with a mass fraction of 16%, and stirring was carried out at a rotating speed of 560 rpm for 14 min until the mica powder was uniformly dispersed, then the pH value of the mixture was adjusted to 8.6 by using sodium carbonate-sodium bicarbonate buffer solution, then tetraethyl orthosilicate was added, the temperature was increased to 58℃, and the rotating speed was kept unchanged, and the mixture was continuously stirred for 5 h, then the pH value of the mixture was adjusted to neutral by using an acetic acid aqueous solution with a mass fraction of 3%, and the mixture was centrifuged at a rotating speed of 7000 rpm for 14 min, then the mixture was washed with anhydrous ethanol and deionized water for 3 times respectively (the mass of anhydrous ethanol and deionized water was 15% of the mass of the ethanol aqueous solution), and then the mixture was dried at 55℃ until the mass was constant, calcined, the calcination temperature was controlled at 1100℃, and the calcination time was 2.2 h to obtain core-shell particles, wherein the mass ratio of mica powder to hydrochloric acid aqueous solution was 1:30, the mass ratio of pretreated mica powder, ethanol aqueous solution and tetraethyl orthosilicate was 0.6:60:0.46, and the specific process parameters of acid pickling were as follows: the mass fraction of hydrochloric acid aqueous solution was 8%, the acid pickling temperature was 45℃, and the acid pickling time was 0.6 h;
[0053] Step B2, the core-shell particles, deionized water, anhydrous ethanol and KH-560 are uniformly mixed by ultrasonic, the ultrasonic frequency is controlled to be 35 kHz, the ultrasonic power is controlled to be 500 W, the ultrasonic time is controlled to be 14 min, the temperature is controlled to be 50 DEG C, the rotating speed is controlled to be 640 rpm, the stirring is continued for 5.4 h, centrifugation is carried out, the centrifugal speed is controlled to be 7200 rpm, the centrifugal time is controlled to be 10 min, then the obtained product is washed with anhydrous ethanol and deionized water for 3 times respectively (the mass of anhydrous ethanol and deionized water is 15% of the mass of the ethanol aqueous solution), and the obtained product is dried at 54 DEG C until the weight is constant, to obtain the epoxidized core-shell particles, the epoxidized core-shell particles and anhydrous DMF are uniformly dispersed by ultrasonic, the ultrasonic frequency is controlled to be 35 kHz, the ultrasonic power is controlled to be 500 W, the ultrasonic time is controlled to be 16 min, the mixture b of triethylamine, 4-vinylbenzyl chloride and anhydrous DMF is added dropwise under the condition of stirring at the rotating speed of 560 rpm, the dropping is controlled to be completed within 10 min, the dropping rate is controlled to be 3 drops / s, after the dropping is completed, the temperature is controlled to be 88 DEG C, the rotating speed is kept unchanged, the stirring reaction is carried out for 2.2 h, centrifugation is carried out, the centrifugal speed is controlled to be 7200 rpm, the centrifugal time is controlled to be 10 min, then the obtained product is washed with anhydrous ethanol and deionized water for 3 times respectively (the mass of anhydrous ethanol and deionized water is 15% of the mass of the ethanol aqueous solution), and the obtained product is dried at 54 DEG C until the weight is constant, to obtain the modified filler, wherein the mass ratio of the core-shell particles, deionized water, anhydrous ethanol and KH-560 is 2.4:10:20:0.14; the mass ratio of the epoxidized core-shell particles, anhydrous DMF and the mixture b is 0.8:40:16, and the mass ratio of triethylamine, 4-vinylbenzyl chloride and anhydrous DMF in the mixture b is 0.02:0.18:10;
[0054] Example 2
[0055] The present embodiment provides a powder coating applied to pipeline protection, which comprises the following raw materials in parts by weight: 45 parts of functionalized epoxy resin component, 20 parts of silicone resin, 25 parts of phenolic resin, 6 parts of 1,4-butanediol diglycidyl ether, 7.5 parts of TEGO 1484, 20 parts of modified filler, 1.6 parts of 2-ethyl-4-methylimidazole, 19 parts of polyetheramine D230 and 0.4 parts of 2,4,6-trimethylbenzoyl-diphenylphosphine oxide;
[0056] A preparation method of a powder coating applied to pipeline protection, which comprises the following steps:
[0057] Step S1, the functionalized epoxy resin component, the silicone resin, the phenolic resin, the 1,4-butanediol diglycidyl ether and the TEGO 1484 are mixed at the rotating speed of 450 rpm for 14 min until they are uniform, vacuum degassing is carried out at the temperature of 55 DEG C and the vacuum degree of 0.4 kPa for 35 min, to prepare component A;
[0058] Step S2: Mix the modified filler, 2-ethyl-4-methylimidazolium, polyetheramine D230 and 2,4,6-trimethylbenzoyl-diphenylphosphine oxide at 550 rpm for 12 min until homogeneous to prepare component B;
[0059] Step S3: Stir component A and component B at 580 rpm for 18 minutes until homogeneous, then place the mixture at a wavelength of 365 nm and an intensity of 80 mW / cm². 2 Under ultraviolet light, the material is irradiated for 16 minutes, then extruded through a twin-screw extruder, pulverized, and passed through a 160-mesh sieve to obtain a powder coating for pipeline protection. The extrusion process of the twin-screw extruder is as follows: Zone 1 90℃, Zone 2 112℃, Zone 3 105℃, Zone 4 100℃, Zone 5 102℃, die head temperature 105℃, and screw speed 200rpm.
[0060] The functionalized epoxy resin component is prepared by the following steps:
[0061] Step A1: Add 4,6-diamino-2-mercaptopyrimidine, 4-hydroxyphthalic anhydride, and tetrabutylammonium bromide to anhydrous THF, control the stirring speed at 540 rpm, stir for 16 min until homogeneous, raise the temperature to reflux temperature, maintain the stirring speed at a constant speed, stir for 14 h, cool to room temperature, and rotary evaporate at 44 °C until anhydrous THF is removed to obtain a carboxyl monomer, wherein the mass ratio of 4,6-diamino-2-mercaptopyrimidine, 4-hydroxyphthalic anhydride, tetrabutylammonium bromide, and anhydrous THF is 1.5:1.65:0.03:45;
[0062] Step A2: Add the carboxyl monomer to anhydrous DMF, control the stirring speed at 580 rpm, and stir for 18 min until homogeneous. Add dropwise a mixture of N,N-dicyclohexylcarbodiimide, 4-dimethylaminopyridine, 4-aminopiperidine, and anhydrous DMF, controlling the addition to be completed within 15 min at a dropping rate of 4 drops / second. After the addition is complete, raise the temperature to 80℃, maintain the stirring speed, and continue stirring for 3.4 h. Centrifuge at 7200 rpm for 14 min. The solution was then washed four times each with anhydrous ethanol and deionized water (each time the mass of anhydrous ethanol and deionized water was 15% of the mass of anhydrous DMF), and dried at 66°C to constant weight to obtain a piperidinyl compound. The mass ratio of the carboxyl monomer, anhydrous DMF, and mixture a was 3.5:45:25. In mixture a, the mass ratio of N,N-dicyclohexylcarbodiimide, 4-dimethylaminopyridine, 4-aminopiperidine, and anhydrous DMF was 2.9:1.6:1.2:15.
[0063] Step A3, the piperidyl compound and triethylamine are added into anhydrous DMF, the temperature is raised to 45℃, the stirring speed is controlled at 580 rpm, and the stirring is performed for 18 min until the mixture is uniform, the epichlorohydrin is added dropwise, the dropping is completed within 10 min, the dropping rate is controlled at 4 drops per second, after the dropping is completed, the temperature is raised to 67℃, the stirring speed is kept unchanged, and the stirring is continued for 5 h, the anhydrous DMF is removed by distillation under reduced pressure, the distillation temperature under reduced pressure is controlled at 78℃, and the vacuum degree is 5.0 kPa, thereby obtaining the functionalized epoxy resin component, wherein the mass ratio of the piperidyl compound, triethylamine, anhydrous DMF and epichlorohydrin is 2:0.03:55:0.49;
[0064] The modified filler is prepared by the following steps:
[0065] Step B1, the mica powder is added into the hydrochloric acid aqueous solution for acid pickling treatment, and then filtered, washed with anhydrous ethanol and deionized water for 4 times respectively (the mass of anhydrous ethanol and deionized water is 15% of the mass of the hydrochloric acid aqueous solution), dried at 60℃, crushed, and sieved through a 450 mesh screen, thereby obtaining the pretreated mica powder; the pretreated mica powder is added into an ethanol aqueous solution with a mass fraction of 18%, the stirring speed is controlled at 600 rpm, and the stirring is performed for 16 min until the mixture is uniform, the pH value is adjusted to 8.9 by using a sodium carbonate-sodium bicarbonate buffer solution, the tetraethyl orthosilicate is added, the temperature is raised to 61℃, the stirring speed is kept unchanged, and the stirring is continued for 6.5 h, after the reaction is completed, the pH value is adjusted to neutral by using an acetic acid aqueous solution with a mass fraction of 4%, centrifuged at a centrifugal speed of 7500 rpm for 16 min, and then washed with anhydrous ethanol and deionized water for 4 times respectively (the mass of anhydrous ethanol and deionized water is 15% of the mass of the ethanol aqueous solution), dried at 60℃ until the weight is constant, and then calcined at a calcination temperature of 1200℃ for 2.3 h, thereby obtaining the core-shell particle, wherein the mass ratio of the mica powder and the hydrochloric acid aqueous solution is 1:35, the mass ratio of the pretreated mica powder, the ethanol aqueous solution and the tetraethyl orthosilicate is 0.7:70:0.49, and the specific process parameters for the acid pickling are as follows: the mass fraction of the hydrochloric acid aqueous solution is 10%, the acid pickling temperature is 50℃, and the acid pickling time is 0.75 h;
[0066] Step B2, the core-shell particles, deionized water, anhydrous ethanol and KH-560 are uniformly mixed by ultrasonic, the ultrasonic frequency is controlled to be 40 kHz, the ultrasonic power is controlled to be 550 W, the ultrasonic time is controlled to be 16 min, the temperature is controlled to be 53℃, the rotating speed is controlled to be 660 rpm, the stirring is continued for 5.7 h, centrifugation is performed, the centrifugal speed is controlled to be 7400 rpm, the centrifugal time is controlled to be 12 min, then the obtained product is washed with anhydrous ethanol and deionized water for 4 times respectively (the mass of anhydrous ethanol and deionized water is 15% of the mass of the ethanol aqueous solution), and the obtained product is dried at 56℃ until the weight is constant, to obtain the epoxidized core-shell particles, the epoxidized core-shell particles and anhydrous DMF are uniformly dispersed by ultrasonic, the ultrasonic frequency is controlled to be 40 kHz, the ultrasonic power is controlled to be 550 W, the ultrasonic time is controlled to be 18 min, the mixture b of triethylamine, 4-vinylbenzyl chloride and anhydrous DMF is added dropwise under the condition of stirring at a rotating speed of 580 rpm, the dropping is completed within 10 min, the dropping rate is controlled to be 4 drops per second, after the dropping is completed, the temperature is controlled to be 90℃, the rotating speed is kept unchanged, the stirring reaction is performed for 2.5 h, centrifugation is performed, the centrifugal speed is controlled to be 7600 rpm, the centrifugal time is controlled to be 14 min, then the obtained product is washed with anhydrous ethanol and deionized water for 4 times respectively (the mass of anhydrous ethanol and deionized water is 15% of the mass of the ethanol aqueous solution), and the obtained product is dried at 58℃ until the weight is constant, to obtain the modified filler, wherein the mass ratio of the core-shell particles, deionized water, anhydrous ethanol and KH-560 is 2.8:13:25:0.17, the mass ratio of the epoxidized core-shell particles, anhydrous DMF and the mixture b is 1:45:16, and the mass ratio of triethylamine, 4-vinylbenzyl chloride and anhydrous DMF in the mixture b is 0.04:0.2:10.
[0067] Example 3
[0068] The embodiment provides a powder coating applied to pipeline protection, which comprises the following raw materials in parts by weight: 50 parts of a functionalized epoxy resin component, 25 parts of a silicone resin, 30 parts of a phenolic resin, 7 parts of butyl glycidyl ether, 10 parts of BYK-329, 25 parts of a modified filler, 1.8 parts of 2,4,6-tris(dimethylaminomethyl)phenol, 20 parts of diethylenetriamine and 0.5 part of 2,4,6-trimethylbenzoyl-diphenylphosphine oxide.
[0069] A preparation method of a powder coating applied to pipeline protection, which comprises the following steps:
[0070] Step S1, the functionalized epoxy resin component, the silicone resin, the phenolic resin, the butyl glycidyl ether and the BYK-329 are mixed at a rotating speed of 500 rpm for 16 min until they are uniform, vacuum degassing is performed at a temperature of 60℃ and a vacuum degree of 0.2 kPa for 40 min, to obtain component A;
[0071] Step S2, mixing the modified filler, 2,4,6-tris(dimethylaminomethyl)phenol, diethylenetriamine and 2,4,6-trimethylbenzoyl-diphenylphosphine oxide at a rotation speed of 600 rpm for 14 min to be uniform, to prepare component B;
[0072] Step S3, stirring component A and component B at a rotation speed of 600 rpm for 20 min to be uniform, then placing under ultraviolet light with a wavelength of 365 nm and an intensity of 80 mW / cm 2 Step S4, extruding the mixture through a twin-screw extruder, crushing, sieving through a 180-mesh sieve, to obtain a powder coating for pipeline protection, wherein the extrusion process of the twin-screw extruder is: 100℃ for zone 1, 120℃ for zone 2, 110℃ for zone 3, 105℃ for zone 4, 105℃ for zone 5, a die temperature of 105℃, and a screw rotation speed of 200 rpm;
[0073] The functionalized epoxy resin component is prepared by the following steps:
[0074] Step A1, adding 4,6-diamino-2-mercapto pyrimidine, 4-hydroxy phthalic anhydride and tetrabutylammonium bromide into anhydrous THF, stirring at a rotation speed of 580 rpm for 20 min to be uniform, heating to reflux temperature, maintaining the rotation speed unchanged, stirring for 16 h, cooling to room temperature, rotary evaporation, controlling the rotary evaporation temperature to be 44℃, rotary evaporation to remove anhydrous THF, to obtain a carboxyl monomer, wherein the mass ratio of 4,6-diamino-2-mercapto pyrimidine, 4-hydroxy phthalic anhydride, tetrabutylammonium bromide and anhydrous THF is 2:2.2:0.04:50;
[0075] Step A2, adding the carboxyl monomer into anhydrous DMF, stirring at a rotation speed of 600 rpm for 18 min to be uniform, adding dropwise a mixed solution a of N,N-dicyclohexyl carbodiimide, 4-dimethylamino pyridine, 4-aminopiperidine and anhydrous DMF, controlling the dropwise addition to be completed within 15 min, controlling the dropwise addition rate to be 5 drops per second, after dropwise addition, heating to 82℃, maintaining the rotation speed unchanged, continuing to stir for 3.6 h, centrifuging, controlling the centrifugation rotation speed to be 7400 rpm, centrifuging for 16 min, then sequentially washing with anhydrous ethanol and deionized water for 5 times (the mass of anhydrous ethanol and deionized water is 15% of the mass of anhydrous DMF each time), drying at 68℃ to a constant weight, to obtain a piperidyl compound, wherein the mass ratio of the carboxyl monomer, anhydrous DMF and the mixed solution a is 4:50:30, and in the mixed solution a, the mass ratio of N,N-dicyclohexyl carbodiimide, 4-dimethylamino pyridine, 4-aminopiperidine and anhydrous DMF is 3.2:1.8:1.4:15;
[0076] Step A3, the piperidyl compound and triethylamine are added into anhydrous DMF, the temperature is raised to 50℃, the stirring speed is controlled at 600 rpm, and the stirring is performed for 20 min until the mixture is uniform, the epichlorohydrin is added dropwise, the dropping is completed within 10 min, the dropping rate is controlled at 5 drops / sec, after the dropping is completed, the temperature is raised to 70℃, the stirring speed is kept unchanged, and the stirring is continued for 5.4 h, the anhydrous DMF is removed by distillation under reduced pressure, the distillation temperature under reduced pressure is controlled at 80℃, and the vacuum degree is 5.2 kPa, thereby obtaining the functionalized epoxy resin component, wherein the mass ratio of the piperidyl compound, triethylamine, anhydrous DMF and epichlorohydrin is 2.4:0.04:60:0.58;
[0077] The modified filler is prepared by the following steps:
[0078] Step B1, the mica powder is added into the hydrochloric acid aqueous solution for acid pickling treatment, and then filtered, and then washed with anhydrous ethanol and deionized water for 5 times (the mass of the anhydrous ethanol and the deionized water is 15% of the mass of the hydrochloric acid aqueous solution), dried at 62℃, crushed, and then passed through a 500-mesh sieve to obtain pretreated mica powder; the pretreated mica powder is added into an ethanol aqueous solution with a mass fraction of 20%, the stirring speed is controlled at 600 rpm, and the stirring is performed for 24 min until the mixture is uniform, the pH value is adjusted to 9.2 by using a sodium carbonate-sodium bicarbonate buffer solution, then the tetraethyl orthosilicate is added, the temperature is raised to 64℃, the stirring speed is kept unchanged, and the stirring is continued for 8 h, after the reaction is completed, the pH value is adjusted to neutral by using a 5%-mass fraction acetic acid aqueous solution, centrifuged at a centrifugal speed of 8000 rpm for 18 min, and then washed with anhydrous ethanol and deionized water for 5 times (the mass of the anhydrous ethanol and the deionized water is 15% of the mass of the ethanol aqueous solution), dried at 65℃ until the weight is constant, and then calcined at a calcination temperature of 1300℃ for 2.4 h to obtain the core-shell particle, wherein the mass ratio of the mica powder and the hydrochloric acid aqueous solution is 1:40, and the mass ratio of the pretreated mica powder, the ethanol aqueous solution and the tetraethyl orthosilicate is 0.8:80:0.52; the specific process parameters for the acid pickling are as follows: the mass fraction of the hydrochloric acid aqueous solution is 12%, the acid pickling temperature is 55℃, and the acid pickling time is 0.9 h;
[0079] Step B2, the core-shell particles, deionized water, anhydrous ethanol and KH-560 are uniformly mixed by ultrasonic, the ultrasonic frequency is controlled to be 45 kHz, the ultrasonic power is controlled to be 600 W, the ultrasonic time is 16 min, the temperature is raised to 56 °C, the rotating speed is controlled to be 680 rpm, the stirring is continued for 6 h, centrifugation is performed, the centrifugal rotating speed is controlled to be 7600 rpm, the centrifugal time is 14 min, then the obtained product is washed with anhydrous ethanol and deionized water for 5 times respectively (the mass of anhydrous ethanol and deionized water is 15% of the mass of the ethanol aqueous solution), and the obtained product is dried at 58 °C until the weight is constant, to obtain the epoxidized core-shell particles, the epoxidized core-shell particles and anhydrous DMF are uniformly dispersed by ultrasonic, the ultrasonic frequency is controlled to be 45 kHz, the ultrasonic power is controlled to be 600 W, the ultrasonic time is 20 min, the mixture liquid b of triethylamine, 4-vinylbenzyl chloride and anhydrous DMF is added dropwise under the condition of stirring at a rotating speed of 600 rpm, after the dropwise addition is completed, the temperature is raised to 92 °C, the rotating speed is kept unchanged, the stirring reaction is performed for 2.8 h, centrifugation is performed, the centrifugal rotating speed is controlled to be 8000 rpm, the centrifugal time is 16 min, then the obtained product is washed with anhydrous ethanol and deionized water for 5 times respectively (the mass of anhydrous ethanol and deionized water is 15% of the mass of the ethanol aqueous solution), and the obtained product is dried at 62 °C until the weight is constant, to obtain the modified filler, wherein the mass ratio of the core-shell particles, deionized water, anhydrous ethanol and KH-560 is 3.2:16:30:0.2, the mass ratio of the epoxidized core-shell particles, anhydrous DMF and the mixture liquid b is 1.2:50:16, and the mass ratio of triethylamine, 4-vinylbenzyl chloride and anhydrous DMF in the mixture liquid b is 0.06:0.22:10.
[0080] Comparative Example 1
[0081] Comparative Example 1 is the same as Example 1, except that in the preparation process of the functionalized epoxy resin component, 4,6-diamino-2-mercapto pyrimidine is replaced by an equal mass of 2,4-diaminopyrimidine, and the remaining steps and raw materials are the same as Example 1.
[0082] Comparative Example 2
[0083] Comparative Example 2 is the same as Example 1, except that in the preparation process of the functionalized epoxy resin component, 4-hydroxy phthalic anhydride is replaced by an equal mass of 2-methyl succinic anhydride, and the remaining steps and raw materials are the same as Example 1.
[0084] Comparative Example 3
[0085] Comparative Example 3 is the same as Example 1, except that in the preparation process of the functionalized epoxy resin component, 4-aminopiperidine is replaced by an equal mass of aniline, and the remaining steps and raw materials are the same as Example 1.
[0086] Comparative Example 4
[0087] Comparative Example 4 is the same as Example 1, except that in the preparation of the modified filler, 4-vinylbenzyl chloride is replaced by an equal amount of 2-(chloroethyl)benzene, and the remaining steps and raw materials are the same as in Example 1.
[0088] Performance test
[0089] I. Preparation of test samples: The Q235 iron plate (150 mm x 75 mm) was subjected to oil removal, dust removal treatment, and sanded with 400 mesh sandpaper. After washing the surface with ethanol and drying, it was ready for use. The powder coatings prepared in Examples 1-3 and Comparative Examples 1-4 were electrostatically sprayed, with a controlled coating thickness of 100 μm, and then treated at 150°C for 30 min to obtain test samples. The specific process parameters for electrostatic spraying were: powder spraying amount controlled at 100 g / min, flow rate pressure at 0.42 MPa, atomization pressure at 0.35 MPa, and conveying chain speed at 5 m / min.
[0090] According to GB / T 5478-2008 "Plastics - Rolling abrasion test method" and QJ-Taber abrasion tester, the abrasion mass after 1000 rpm was tested at a rotation speed of 70±1 rpm. The impact resistance test was performed according to GB / T 1732-2020 "Paint film impact resistance test method". The pencil hardness test was performed according to GB / T 6739-2022 "Color paint and varnish - Pencil method for determining paint film hardness". The adhesion test standard refers to GB / T 9286-2021 "Color paint and varnish - Cross-hatch test". The specific test results are shown in Table 1.
[0091] Table 1 Mechanical property test results of powder coatings for pipeline protection
[0092]
[0093] As can be seen from Table 1, compared with Comparative Examples 1-4, the powder coatings for pipeline protection prepared by the method provided in Examples 1-3 have more excellent mechanical properties.
[0094] II. Weather resistance test of powder coatings for pipeline protection
[0095] The waterproofness and weather resistance of the test samples prepared in Examples 1-3 and Comparative Examples 1-4 were tested. The waterproofness was tested according to the standard GB / T 1733-1993, the test sample was immersed in boiling deionized water, and after 90 days of immersion, the sample was dried and observed for phenomena such as blistering, peeling, cracking, and powdering. The salt spray resistance was tested according to the standard GB / T 1771-2007. The alkali resistance was tested according to the standard GB / T 9274-1988, the test sample prepared in Examples 1-3 and Comparative Examples 1-4 was immersed in 0.1M NaOH solution, and after 90 days of immersion, the sample was dried and observed for phenomena such as blistering, peeling, cracking, and powdering. The acid resistance was also tested according to the standard GB / T 9274-1988, the test sample prepared in Examples 1-3 and Comparative Examples 1-4 was immersed in 0.05M H2SO4 solution, and after 90 days of immersion, the sample was dried and observed for phenomena such as blistering, peeling, cracking, and powdering. The specific test results are shown in Table 2.
[0096] Table 2 Weather resistance test results of powder coatings for pipeline protection
[0097]
[0098] As can be seen from Table 2, compared with Comparative Example 1-4, the powder coating for pipeline protection prepared in Example 1-3 has more excellent salt spray resistance, acid resistance, and alkali resistance, which indicates that the powder coating for pipeline protection prepared in Example 1-3 has more excellent waterproofness and weather resistance.
[0099] The specific embodiments are merely illustrative of the present application, and are not intended to limit the present application. Those skilled in the art can make modifications to the embodiments without creative contribution after reading the specification, and as long as the modifications are within the scope of the claims of the present application, they are protected by the patent law.
Claims
1. A powder coating for pipeline protection, characterized in that, The raw materials include the following parts by weight: 40-50 parts functionalized epoxy resin component, 15-25 parts silicone resin, 20-30 parts phenolic resin, 5-7 parts diluent, 5-10 parts leveling agent, 15-25 parts modified filler, 1.4-1.8 parts accelerator, 18-20 parts curing agent and 0.3-0.5 parts photoinitiator; The functionalized epoxy resin component is first prepared by ring-opening reaction of 4,6-diamino-2-mercaptopyrimidine and 4-hydroxyphthalic anhydride to obtain a carboxyl monomer, then by amidation reaction of 4-aminopiperidine to obtain a piperidinyl compound, and finally by nucleophilic substitution reaction of epichlorohydrin. The modified filler is first prepared by treating mica powder with hydrochloric acid aqueous solution to obtain pretreated mica powder, then coating it with tetraethyl orthosilicate to obtain core-shell particles, then modifying it with KH-560 to obtain epoxidized core-shell particles, and finally preparing it by nucleophilic substitution reaction with 4-vinylbenzyl chloride.
2. The powder coating for pipeline protection according to claim 1, characterized in that, The functionalized epoxy resin component is prepared by the following steps: Step A1: Add 4,6-diamino-2-mercaptopyrimidine, 4-hydroxyphthalic anhydride and tetrabutylammonium bromide to anhydrous THF, stir until homogeneous, heat to reflux temperature, stir and react for 12-16 h, cool to room temperature, and rotary evaporate to obtain carboxyl monomer. Step A2: Add the carboxyl monomer to anhydrous DMF, stir well, and dropwise add a mixture of N,N-dicyclohexylcarbodiimide, 4-dimethylaminopyridine, 4-aminopiperidine and anhydrous DMF. After the addition is complete, heat to 78-82℃, stir the reaction for 3.2-3.6 h, centrifuge, wash, and dry to obtain the piperidinyl compound. Step A3: Add piperidinyl compound and triethylamine to anhydrous DMF, heat to 40-50℃, stir until homogeneous, add epichlorohydrin dropwise, after the addition is complete, heat to 64-70℃, stir and react for 4.6-5.4h, distill under reduced pressure to obtain functionalized epoxy resin component.
3. The powder coating for pipeline protection according to claim 2, characterized in that, In step A1, the mass ratio of 4,6-diamino-2-mercaptopyrimidine, 4-hydroxyphthalic anhydride, tetrabutylammonium bromide, and anhydrous THF is 1-2:1.1-2.2:0.02-0.04:40-50.
4. A powder coating for pipeline protection according to claim 2, characterized in that, In step A2, the mass ratio of carboxyl monomer, anhydrous DMF and mixture a is 3-4:40-50:20-30, and the mass ratio of N,N-dicyclohexylcarbodiimide, 4-dimethylaminopyridine, 4-aminopiperidine and anhydrous DMF in mixture a is 2.6-3.2:1.4-1.8:1-1.4:
15.
5. A powder coating for pipeline protection according to claim 2, characterized in that, In step A3, the mass ratio of piperidinyl compound, triethylamine, anhydrous DMF and epichlorohydrin is 1.6-2.4:0.02-0.04:50-60:0.4-0.
58.
6. A powder coating for pipeline protection according to claim 1, characterized in that, The modified filler is prepared by the following steps: Step B1: Add mica powder to hydrochloric acid aqueous solution for acid washing, filter, wash, dry, pulverize, and sieve to obtain pretreated mica powder. Pretreated mica powder was added to an ethanol-water solution and stirred until homogeneous. The pH was adjusted to 8.6-9.2, and then tetraethyl orthosilicate was added. The temperature was raised to 58-64℃ and stirred for 5-8 hours. After the reaction was completed, the pH was adjusted to neutral, centrifuged, washed, dried, and calcined to obtain core-shell particles. Step B2: Ultrasonically mix the core-shell particles, deionized water, anhydrous ethanol, and KH-560 until homogeneous. Heat to 50-56℃ and continue stirring for 5.4-6 hours. Centrifuge, wash, and dry to obtain epoxidized core-shell particles. Ultrasonically disperse the epoxidized core-shell particles and anhydrous DMF until homogeneous. Add dropwise a mixture of triethylamine, 4-vinylbenzyl chloride, and anhydrous DMF (b). After the addition is complete, heat to 88-92℃ and stir for 2.2-2.8 hours. Centrifuge, wash, and dry to obtain the modified filler.
7. A powder coating for pipeline protection according to claim 6, characterized in that, In step B1, the specific process parameters for pickling are as follows: the mass fraction of hydrochloric acid aqueous solution is 8-12%, the pickling temperature is 45-55℃, and the pickling time is 0.6-0.9h; the mass fraction of ethanol aqueous solution is 16-20%; the calcination temperature is 1100-1300℃, and the calcination time is 2.2-2.4h.
8. A powder coating for pipeline protection according to claim 6, characterized in that, In step B2, the mass ratio of core-shell particles, deionized water, anhydrous ethanol, and KH-560 is 2.4-3.2:10-16:20-30:0.14-0.2; the mass ratio of epoxidized core-shell particles, anhydrous DMF, and mixture b is 0.8-1.2:40-50:16; and in mixture b, the mass ratio of triethylamine, 4-vinylbenzyl chloride, and anhydrous DMF is 0.02-0.06:0.18-0.22:
10.
9. A powder coating for pipeline protection according to claim 1, characterized in that, The diluent is butyl glycidyl ether or 1,4-butanediol diglycidyl ether; the leveling agent is BYK-329 or TEGO 1484; the accelerator is 2,4,6-tris(dimethylaminomethyl)phenol or 2-ethyl-4-methylimidazole; the curing agent is diethylenetriamine or polyetheramine D230; and the photoinitiator is 2,4,6-trimethylbenzoyl-diphenylphosphine oxide.
10. A method for preparing a powder coating for pipeline protection as described in any one of claims 1-9, comprising the following steps: Step S1: Mix the functionalized epoxy resin component, silicone resin, phenolic resin, diluent and leveling agent evenly, and degas under vacuum to prepare component A; Step S2: Mix the modified filler, accelerator, curing agent and photoinitiator evenly to prepare component B; Step S3: Mix component A and component B evenly, irradiate with ultraviolet light for 14-18 minutes, then extrude through a twin-screw extruder, crush, and sieve to obtain a powder coating for pipeline protection.