A method for preparing a fatigue-resistant coating for a guy wire

Abstract

The present application belongs to the technical field of epoxy resin anti-fatigue coating, and particularly relates to a preparation method of an anti-fatigue coating for a pendant line, comprising the following steps: mixing polycaprolactone diol, DBTDL and toluene, adding modified silicon carbide dispersion, adding TDI, mixing and reacting to obtain an inner phase liquid; mixing dimethyl silicone oil and an emulsifier to obtain a dispersion liquid; adding the inner phase liquid into the dispersion liquid, stirring and emulsifying, and then performing a temperature rising reaction; after filtration, washing and drying, a silicon carbide hybrid microcapsule is obtained; then the silicon carbide hybrid microcapsule is dispersed in bisphenol A type epoxy resin, polyamide is added, and vacuum defoaming is performed to obtain a coating; the coating is coated on a pretreated pendant line, and an anti-fatigue coating is obtained after curing. The anti-fatigue coating has excellent bending fatigue resistance during the installation stage of the pendant line, and has excellent wear resistance after being put into use, thereby prolonging the service life of the pendant line.

Description

TECHNICAL FIELD

[0001] The application belongs to the technical field of epoxy resin anti-fatigue coating, and particularly relates to a preparation method of an anti-fatigue coating of a pendant wire. BACKGROUND

[0002] In a catenary system of an electrified railway, a non-current-carrying pendant wire is a key positioning and tension adjusting component. In the micro-motion wear areas such as the upper and lower hooks, the binding area and the contact interface with the metal clamp, surface fatigue wear is easily caused due to the existence of micro-amplitude relative motion, which leads to the peeling of the surface protective layer of the pendant wire, the exposure of the base metal and the acceleration of the corrosion process, and significantly reduces the service life of the pendant wire. In severe cases, it can cause a broken wire accident and threaten the safety of train operation.

[0003] A Chinese patent document with the publication number CN113214718B discloses a wear-resistant coating and a preparation method and application thereof, which contains the following raw materials by weight: 60-80 parts of silicone epoxy resin, 10-20 parts of toluene diisocyanate, 50-70 parts of beta-type silicon carbide whisker, 3-6 parts of carbon fiber, 10-20 parts of reinforcing powder, 8-10 parts of modified dispersant and 1-2 parts of scratch-resistant aid SC050. In the above coating, by introducing high-hardness beta-type silicon carbide whisker, carbon fiber and reinforcing powder into the silicone epoxy resin matrix, the overall wear resistance of the coating is significantly improved. When the above coating is coated on the pendant wire, the surface fatigue wear caused by micro-amplitude relative motion can be effectively inhibited, and the service life of the pendant wire is improved. However, the flexibility and bending fatigue resistance of the above coating are poor. During the installation of the pendant wire, repeated bending, winding and stretching operations are required. The above coating is difficult to deform synchronously with the pendant wire, and micro-cracks or even local peeling are easily generated, resulting in the loss of the protective function. SUMMARY

[0004] The application provides a preparation method of an anti-fatigue coating of a pendant wire. The prepared anti-fatigue coating has excellent bending fatigue resistance during the installation stage of the pendant wire, and has excellent wear resistance after being put into use, thereby prolonging the service life of the pendant wire.

[0005] To solve the above problems, the application adopts the following technical scheme:

[0006] A preparation method of an anti-fatigue coating of a pendant wire, comprising the following steps:

[0007] S1, in inert atmosphere, poly (caprolactone) diol, DBTDL (dibutyl tin dilaurate), toluene are mixed uniformly, then modified silicon carbide dispersion, TDI (toluene diisocyanate) are added, and the pre-polymer mixed solution is obtained by stirring and reacting, in inert atmosphere, the pre-polymer mixed solution, TFEMA (trifluoroethyl methacrylate), PEGMA (poly (ethylene glycol) methyl ether methacrylate), MBA (N,N'-methylene bisacrylamide), free radical initiator are mixed uniformly to obtain the inner phase liquid; the dimethyl silicone oil, emulsifier are mixed uniformly to obtain the dispersion liquid; the inner phase liquid is added into the dispersion liquid, and the emulsion is stirred and emulsified, and the reaction is carried out by heating, and after filtration, washing and drying, the silicon carbide hybrid microcapsule is obtained; the modified silicon carbide is obtained by treating silicon carbide with HPTMS (3-hydroxypropyl trimethoxysilane);

[0008] S2, the silicon carbide hybrid microcapsule is dispersed in bisphenol A type epoxy resin, and polyamide is slowly added under continuous stirring to obtain a coating after mixing and vacuum degassing;

[0009] S3, the coating is coated on the pretreated pendant line, and the anti-fatigue coating is obtained after curing.

[0010] The silicon carbide hybrid microcapsule is dispersed in the matrix composed of bisphenol A epoxy resin and polyamide as a functional filler to prepare a coating, the coating is coated on the surface of the pendant line and cured to obtain an anti-fatigue coating, which has excellent bending fatigue resistance during the installation of the pendant line and can be repeatedly bent synchronously with the pendant line, and after the pendant line is put into use, the shell layer of the silicon carbide hybrid microcapsule is broken due to frequent friction in the fretting wear area, the pre-polymer mixed solution in the microcapsule reacts with the moisture in the air and solidifies to form a polyurea-silicon carbide wear-resistant layer in the fretting wear area, which endows the anti-fatigue coating with excellent local wear resistance and prolongs the service life of the pendant line.

[0011] The shell layer of the silicon carbide hybrid microcapsule is formed by copolymerization and crosslinking of TFEMA, PEGMA and MBA under the initiation of a free radical initiator, and the pre-polymer mixed solution is wrapped inside, the TFEMA molecule contains a trifluoromethyl group, which improves the hydrophobicity of the microcapsule shell layer, inhibits the penetration of moisture, maintains the liquid state of the pre-polymer mixed solution before the microcapsule is broken, avoids the direct dispersion of modified silicon carbide in the matrix, and reduces the influence of the addition of modified silicon carbide on the bending fatigue resistance of the anti-fatigue coating; PEGMA has a flexible segment, which improves the toughness of the microcapsule shell layer and helps the microcapsule to remain intact during processing and storage.

[0012] Further, the modified silicon carbide is prepared by the following method: mixing 8-10 parts by mass of HPTMS and 200-220 parts by mass of a 93-97 wt% ethanol solution, adding an acetic acid solution to adjust the pH value to 4-5, stirring at 300-400 rpm for 1-2 h, adding 20-25 parts by mass of hydrophilic silicon carbide, stirring at 1000-1200 rpm for 15-25 min, heating to 60-70°C, stirring at 300-400 rpm for 3-4 h, filtering, washing with anhydrous ethanol, and then drying at 50-60°C and 10-20 kPa for 10-12 h to obtain the modified silicon carbide; and the hydrophilic silicon carbide is prepared by the following method: mixing 295-303 parts by mass of a 65-70 wt% nitric acid solution and 98-101 parts by mass of a 30-35 wt% hydrogen peroxide solution, adding 28-31 parts by mass of silicon carbide, heating to 73-77°C, stirring at 300-400 rpm for 3-4 h, filtering, washing with deionized water until the pH value of the washing liquid is 7, and then drying at 50-60°C and 10-20 kPa for 8-10 h to obtain the hydrophilic silicon carbide.

[0013] Further, the prepolymer mixture is prepared by the following method: mixing 62-68 parts by mass of polycaprolactone diol, 0.6-0.8 parts by mass of DBTDL, and 130-140 parts by mass of toluene in an inert atmosphere, adding 15-20 parts by mass of modified silicon carbide, stirring at 900-1000 rpm for 20-25 min, heating to 70-80°C, slowly adding 10-13 parts by mass of TDI under continuous stirring, and stirring at 300-400 rpm for 2-3 h to obtain the prepolymer mixture; and the polycaprolactone diol has a Mn of 2000-2200 g / mol.

[0014] The HPTMS undergoes a hydrolysis reaction with water molecules under acidic conditions to generate oligosilanol containing primary alcohol hydroxyl groups and silicon hydroxyl groups. The silicon hydroxyl groups of the oligosilanol and the silicon hydroxyl groups on the surface of the hydrophilic silicon carbide undergo condensation reactions, and the primary alcohol hydroxyl groups are grafted onto the surface of the silicon carbide to obtain modified silicon carbide. This improves the dispersibility of the silicon carbide in the polycaprolactone diol. At the same time, the primary alcohol hydroxyl groups can react with the isocyanate groups of TDI, covalently bonding the modified silicon carbide in the prepolymer mixture and preventing the modified silicon carbide from settling or agglomerating.

[0015] Further, in the step S1, the silicon carbide hybrid microcapsule is prepared by the following method: mixing 90-100 parts by mass of the prepolymer mixture, 2-4 parts by mass of TFEMA, 5-7 parts by mass of PEGMA, 0.2-0.3 parts by mass of MBA, and 0.1-0.2 parts by mass of V-65 (2,2'-azobis(2,4-dimethylvaleronitrile)) in an inert atmosphere to obtain an internal phase liquid; mixing 500-550 parts by mass of dimethyl silicone oil and 1-2 parts by mass of Span-80 to obtain a dispersion liquid; adding the internal phase liquid into the dispersion liquid in an inert atmosphere, stirring at 2500-2700 rpm for 20-30 min, increasing the temperature to 60-65°C, stirring at 500-600 rpm for 3-4 h, and then drying at 30-40°C and 7-10 kPa for 8-12 h after filtration and n-hexane washing to obtain the silicon carbide hybrid microcapsule; the M n of the PEGMA is 400-450 g / mol, and the kinematic viscosity of the dimethyl silicone oil at 25°C is 50-60 mm 2 / s.

[0016] The compatibility of the internal phase liquid with the dimethyl silicone oil is poor, and under the action of the emulsifier Span-80, the internal phase liquid is beneficial to be dispersed in the dispersion liquid and form small droplets; the TFEMA has a low surface energy in the internal phase liquid, and tends to be enriched at the interface of the droplets in the emulsified state, and under the initiation of the free radical initiator V-65, the TFEMA, PEGMA and MBA occur free radical copolymerization to generate a crosslinked product, which has poor compatibility with toluene, and thus continuously deposits at the interface of the droplets and the dispersion liquid, so as to obtain the microcapsule with the liquid prepolymer mixture wrapped inside.

[0017] Further, the coating also includes zeolite hybrid microcapsules, which are prepared by the following method: adding 23-28 parts by mass of zinc stearate modified zeolite into 100-130 parts by mass of deionized water, ultrasonic dispersing at 200-250 W for 15-20 min, mixing 2-4 parts by mass of TFEMA, 5-8 parts by mass of PEGMA, and 0.2-0.3 parts by mass of MBA, adding acetic acid solution to adjust the pH value to 4-5, adding 0.1-0.2 parts by mass of V-50 (2,2'-azobis(2-methyl-2-imidazoline) dihydrochloride), increasing the temperature to 65-70°C, stirring at 300-400 rpm for 2-3 h, cooling, filtering, washing with deionized water and anhydrous ethanol, and then drying at 50-60°C and 10-20 kPa for 8-12 h to obtain the zeolite hybrid microcapsule; the M n of the PEGMA is 450-500 g / mol.

[0018] Further, the zinc stearate modified zeolite is prepared by the following method: dissolving 8-12 parts by mass of zinc stearate in 480-500 parts by mass of toluene at 70-80°C, adding 30-35 parts by mass of zeolite, ultrasonic dispersion at 150-200W for 30-40min, stirring at 300-400rpm for 1-2h, filtering, washing with toluene, and drying at 50-60°C under 10-20kPa for 10-12h to obtain the zinc stearate modified zeolite; the zeolite is USY zeolite.

[0019] The zinc stearate modified zeolite dispersed in deionized water has a hydrophobic surface and can adsorb hydrophobic TFEMA. Under the action of water-soluble free radical initiator V-50, TFEMA and PEGMA and MBA near the surface of the zinc stearate modified zeolite undergo in-situ free radical copolymerization to generate a water-insoluble crosslinked polymer and deposit on the surface of the zinc stearate modified zeolite, forming a polymer shell layer with toughness, thereby obtaining a zeolite hybrid microcapsule. The polymer shell layer can isolate the zeolite from the matrix formed by bisphenol A type epoxy resin and polyamide, effectively avoiding direct contact of the rigid zeolite with the matrix, reducing stress concentration, and avoiding the decrease in the toughness of the anti-fatigue coating.

[0020] Further, in the step S2, 18-23 parts by mass of silicon carbide hybrid microcapsules and 0-12 parts by mass of zeolite hybrid microcapsules are added to 200-220 parts by mass of bisphenol A type epoxy resin, stirred at 600-700rpm for 40-50min, 150-160 parts by mass of polyamide is slowly added under continuous stirring, and mixed uniformly, and then degassed at 10-15kPa for 15-20min to obtain a coating; the epoxy equivalent weight of the bisphenol A type epoxy resin is 210-230g / eq.

[0021] The zeolite hybrid microcapsules and the silicon carbide hybrid microcapsules are added to the matrix formed by the bisphenol A type epoxy resin and the polyamide to obtain a coating, the coating is coated on the outside of the sling line and cured to obtain an anti-fatigue coating. During use, the shell of the zeolite hybrid microcapsules at the fretting wear region is broken, releasing the zinc stearate modified zeolite, and the zinc stearate on the surface of the zinc stearate modified zeolite acts as a solid lubricant to form a lubricating layer at the friction interface, effectively reducing the local friction coefficient. At the same time, the silicon carbide hybrid microcapsules generate polyurea-silicon carbide wear-resistant layers in-situ after breaking, and the zeolite hybrid microcapsules and the silicon carbide hybrid microcapsules synergistically act to significantly improve the wear resistance of the anti-fatigue coating under fretting wear conditions.

[0022] Further, the following method is used for pretreating the sling wire: the sling wire is soaked in 8-10 wt% sodium hydroxide solution for 2-4 min, taken out, washed with deionized water, soaked in KH-560 hydrolysate for 30-40 min, washed with 70-90 wt% ethanol solution, dried at 80-90℃ for 1-2 h, and cooled to complete the pretreatment of the sling wire.

[0023] Further, the KH-560 hydrolysate is prepared by the following method: 10-15 parts by mass of KH-560 and 193-202 parts by mass of 95-97 wt% ethanol solution are mixed, acetic acid solution is added to adjust the pH value to 4-5, and stirring is carried out at 300-400 rpm for 1-2 h to obtain the KH-560 hydrolysate.

[0024] The sodium hydroxide solution is used to soak the sling wire, which is beneficial to remove the grease on the surface of the sling wire and slightly corrode the oxide film, increase the roughness of the surface of the sling wire and the density of the metal hydroxyl group, the condensation reaction occurs between the silicon hydroxyl group of the oligomeric silanol in the KH-560 hydrolysate and the metal hydroxyl group, the epoxy group is grafted and introduced on the surface of the sling wire, which provides active sites for the subsequent ring-opening reaction with polyamide, and is beneficial to the connection of the anti-fatigue coating with the sling wire through the covalent bond, and improves the adhesion of the anti-fatigue coating.

[0025] Further, in the step S3, the pretreated sling wire is soaked in the coating and pulled out upward, and is placed in an environment at 40-50℃ for curing for 72-80 h to obtain the anti-fatigue coating.

[0026] The present application has the following advantages:

[0027] In the present application, the silicon carbide hybrid microcapsule is used as a functional filler and dispersed in a matrix composed of bisphenol A epoxy resin and polyamide to prepare a coating; after the pretreatment of the sling wire, the epoxy group is grafted and introduced on the surface of the sling wire through the Si-O-metal bond, the coating is coated on the surface of the sling wire and cured to obtain an anti-fatigue coating connected with the sling wire through the covalent bond, and the polyamide in the matrix has good toughness, so that the coating can be freely bent along with the sling wire when the sling wire is installed; the shell layer of the silicon carbide hybrid microcapsule is crosslinked by copolymerization of TFEMA, PEGMA and MBA, and the pre-polymer mixture is wrapped inside, the physical coating of the shell layer reduces the influence of the addition of silicon carbide on the bending fatigue resistance of the anti-fatigue coating; during the use of the sling wire, the shell layer is broken due to friction in the fretting wear area, the pre-polymer mixture reacts with the moisture in the air and solidifies to form a polyurea-silicon carbide wear-resistant layer in the fretting wear area, which endows the anti-fatigue coating with excellent local wear resistance and prolongs the service life of the sling wire. DETAILED DESCRIPTION

[0028] Preparation Example One

[0029] Mix 295 g of 70 wt% nitric acid solution and 101 g of 30 wt% hydrogen peroxide solution, add 30 g of silicon carbide with a particle size of 50 nm, heat to 73°C, stir at 300 rpm for 4 h, filter, wash with deionized water until the pH of the eluate is 7, and dry at 50°C under a 10 kPa environment for 10 h to obtain hydrophilic silicon carbide; mix 8 g of HPTMS (3-hydroxypropyltrimethoxysilane) and 200 g of 93 wt% ethanol solution, add 5 wt% acetic acid solution to adjust the pH to 5, stir at 400 rpm for 2 h, add 20 g of hydrophilic silicon carbide, stir at 1000 rpm for 25 min, heat to 65°C, and stir at 300 rpm for 4 h, filter, wash twice with anhydrous ethanol, and dry at 60°C under a 20 kPa environment for 10 h to obtain modified silicon carbide; mix 65 g of polycaprolactone diol (Mn n n Mix 65 g of polycaprolactone diol (Mn

[0030] Preparation Example Two

[0031] Mix 303 g of 65 wt% nitric acid solution and 98 g of 35 wt% hydrogen peroxide solution, add 28 g of silicon carbide with a particle size of 50 nm, heat to 77°C, stir at 400 rpm for 3 h, filter, wash with deionized water until the pH of the eluate is 7, and dry at 60°C under a 20 kPa environment for 8 h to obtain hydrophilic silicon carbide; mix 9 g of HPTMS and 210 g of 95 wt% ethanol solution, add 5 wt% acetic acid solution to adjust the pH to 4, stir at 300 rpm for 2 h, add 22 g of hydrophilic silicon carbide, stir at 1100 rpm for 20 min, heat to 60°C, and stir at 400 rpm for 3 h, filter, wash twice with anhydrous ethanol, and dry at 50°C under a 10 kPa environment for 12 h to obtain modified silicon carbide; mix 62 g of polycaprolactone diol (Mn n Mix 65 g of polycaprolactone diol (Mn

[0032] Preparation Example Three

[0033] Mix 290 g of 68 wt% nitric acid solution and 100 g of 33 wt% hydrogen peroxide solution, add 31 g of silicon carbide with a particle size of 50 nm, heat to 75°C, stir at 350 rpm for 3.5 h, filter, wash with deionized water until the pH of the effluent is 7, and dry at 55°C under a 15 kPa environment for 9 h to obtain hydrophilic silicon carbide; mix 10 g of HPTMS and 220 g of 97 wt% ethanol solution, add 5 wt% acetic acid solution to adjust the pH to 4.5, stir at 350 rpm for 1.5 h, add 25 g of hydrophilic silicon carbide, stir at 1200 rpm for 15 min, heat to 70°C, and stir at 350 rpm for 3.5 h, filter, wash twice with anhydrous ethanol, and dry at 55°C under a 15 kPa environment for 11 h to obtain modified silicon carbide; mix 68 g of polycaprolactone diol (M n is 2200 g / mol), 0.8 g of DBTDL, and 140 g of toluene under a nitrogen atmosphere, stir at 300 rpm for 10 min, add 17 g of modified silicon carbide, stir at 950 rpm for 23 min, heat to 75°C, slowly add 13 g of TDI under stirring at 500 rpm, after the addition is complete, stir at 350 rpm for 2.5 h to obtain a prepolymer mixture.

[0034] Example One

[0035] Mix 100 g of the prepolymer mixture, 2 g of TFEMA (trifluoroethyl methacrylate), 6 g of PEGMA (poly(ethylene glycol) methyl ether methacrylate, M n is 400 g / mol), 0.3 g of MBA (N,N'-methylenebisacrylamide), and 0.15 g of V-65 (2,2'-azobis(2,4-dimethylvaleronitrile)) under a nitrogen atmosphere, stir at 500 rpm for 10 min to obtain an internal phase liquid; mix 500 g of dimethyl silicone oil (kinematic viscosity at 25°C is 50 mm 2Silicon carbide hybrid microcapsules were obtained by mixing 20 g of the inner phase liquid with 1 g of Span-80, stirring at 500 rpm for 20 min to obtain a dispersion liquid; the inner phase liquid was added to the dispersion liquid under a nitrogen atmosphere, stirring at 2500 rpm for 25 min, heating to 65 °C, stirring at 500 rpm for 3 h, filtering, washing with n-hexane for 3 times, and drying at 40 °C under a 7 kPa environment for 10 h; 10 g of zinc stearate was added to 500 g of toluene, heating to 70 °C, stirring at 300 rpm for 20 min, adding 30 g of USY zeolite with a particle size of 100 nm, ultrasonic dispersing at 200 W for 30 min, stirring at 400 rpm for 1 h, cooling to room temperature, filtering, washing with toluene for 2 times, and drying at 50 °C under a 10 kPa environment for 10 h to obtain zinc stearate modified zeolite; 25 g of the zinc stearate modified zeolite was added to 100 g of deionized water, ultrasonic dispersing at 200 W for 20 min, adding 3 g of TFEMA, 6 g of PEGMA (M n Zeolite hybrid microcapsules were obtained by mixing 20 g of the inner phase liquid with 1 g of Span-80, stirring at 500 rpm for 20 min to obtain a dispersion liquid; the inner phase liquid was added to the dispersion liquid under a nitrogen atmosphere, stirring at 2500 rpm for 25 min, heating to 65 °C, stirring at 500 rpm for 3 h, filtering, washing with n-hexane for 3 times, and drying at 40 °C under a 7 kPa environment for 10 h; 10 g of zinc stearate was added to 500 g of toluene, heating to 70 °C, stirring at 300 rpm for 20 min, adding 30 g of USY zeolite with a particle size of 100 nm, ultrasonic dispersing at 200 W for 30 min, stirring at 400 rpm for 1 h, cooling to room temperature, filtering, washing with toluene for 2 times, and drying at 50 °C under a 10 kPa environment for 10 h to obtain zinc stearate modified zeolite; 25 g of the zinc stearate modified zeolite was added to 100 g of deionized water, ultrasonic dispersing at 200 W for 20 min, adding 3 g of TFEMA, 6 g of PEGMA (M

[0036] The coating was prepared by mixing 20 g of the silicon carbide hybrid microcapsules and 10 g of the zeolite hybrid microcapsules into 200 g of bisphenol A type epoxy resin (epoxy equivalent weight of 220 g / eq), stirring at 600 rpm for 40 min, slowly adding 150 g of polyamide under stirring at 300 rpm, stirring at 400 rpm for 30 min, and vacuum degassing at 10 kPa for 15 min.

[0037] The KH-560 hydrolysis solution was prepared by mixing 10 g of KH-560 (γ-glycidoxypropyltrimethoxysilane) with 200 g of 95 wt% ethanol solution, adjusting the pH value to 5 by adding a 5 wt% acetic acid solution, and stirring at 400 rpm for 2 h; the pendant line was soaked in a 10 wt% sodium hydroxide solution for 2 min, taken out, washed with deionized water for 2 times, soaked in the KH-560 hydrolysis solution for 30 min, taken out, washed with a 70 wt% ethanol solution for 2 times, placed in an oven preheated to 80 °C for drying for 1 h, taken out, and naturally cooled to complete the pretreatment of the pendant line; the pretreated pendant line was immersed in the coating, taken out at a uniform speed of 5 mm / s, and placed in a 40 °C environment for curing for 72 h to obtain the anti-fatigue coating.

[0038] The prepolymer mixture used in this example was prepared according to Preparation Example One.

[0039] Example Two

[0040] Under nitrogen atmosphere, 100 g of prepolymer mixture, 3 g of TFEMA, 5 g of PEGMA (M n 450 g / mol), 0.2 g of MBA, 0.1 g of V-65 were mixed, stirred at 500 rpm for 10 min to obtain an internal phase liquid; 550 g of dimethyl silicone oil (kinematic viscosity of 55 mm 2 / s at 25 °C), 1.5 g of Span-80 were mixed, stirred at 500 rpm for 20 min to obtain a dispersion liquid; under nitrogen atmosphere, the internal phase liquid was added to the dispersion liquid, stirred at 2600 rpm for 30 min, heated to 62 °C, stirred at 550 rpm for 4 h, filtered, washed with n-hexane for 3 times, and dried at 30 °C under 7 kPa for 8 h to obtain the silicon carbide hybrid microcapsule; 10 g of zinc stearate was added to 490 g of toluene, heated to 75 °C, stirred at 300 rpm for 20 min, 35 g of USY zeolite with a particle size of 100 nm was added, ultrasonically dispersed at 180 W for 35 min, stirred at 400 rpm for 1 h, cooled to room temperature, filtered, washed with toluene for 2 times, and dried at 60 °C under 20 kPa for 10 h to obtain the zinc stearate modified zeolite; 23 g of the zinc stearate modified zeolite was added to 110 g of deionized water, ultrasonically dispersed at 220 W for 17 min, 2 g of TFEMA, 5 g of PEGMA (M n 460 g / mol), 0.2 g of MBA were added, stirred at 400 rpm for 30 min, 10 wt% acetic acid solution was added dropwise to adjust the pH value to 4, 0.1 g of V-50 was added, heated to 65 °C, stirred at 400 rpm for 2 h, cooled to room temperature, filtered, washed with deionized water for 3 times, washed with anhydrous ethanol for 3 times, and dried at 50 °C under 10 kPa for 10 h to obtain the zeolite hybrid microcapsule.

[0041] 18 g of the silicon carbide hybrid microcapsule and 10 g of the zeolite hybrid microcapsule were added to 210 g of bisphenol A type epoxy resin (epoxy equivalent weight of 225 g / eq), stirred at 650 rpm for 50 min, 155 g of polyamide was slowly added under the condition of stirring at 300 rpm, stirred at 400 rpm for 30 min, and vacuum degassed at 15 kPa for 20 min to obtain a coating.

[0042] Mix 12 g of KH-560, 202 g of 97 wt% ethanol solution, adjust pH value to 4 by adding 5 wt% acetic acid solution, stir at 300 rpm for 2 h to obtain a KH-560 hydrolysate; dip the string into 8 wt% sodium hydroxide solution for 4 min, take out, wash with deionized water for 2 times, dip into the KH-560 hydrolysate for 35 min, take out, wash with 80 wt% ethanol solution for 2 times, place in an oven preheated to 90 ℃ for drying for 1 h, take out, and naturally cool to complete the pretreatment of the string; dip the pretreated string into the coating, take out at a uniform speed of 5 mm / s, and place in a 50 ℃ environment for curing for 76 h to obtain an anti-fatigue coating.

[0043] The prepolymer mixture used in this example is prepared according to Preparation Example One.

[0044] Example Three

[0045] Mix 90 g of the prepolymer mixture, 4 g of TFEMA, 5 g of PEGMA (M n 420 g / mol), 0.3 g of MBA, and 0.2 g of V-65 under a nitrogen atmosphere, stir at 500 rpm for 10 min to obtain an internal phase liquid; mix 520 g of dimethyl silicone oil (kinematic viscosity of 60 mm 2 / s at 25 ℃) and 2 g of Span-80, stir at 500 rpm for 20 min to obtain a dispersion liquid; add the internal phase liquid to the dispersion liquid under a nitrogen atmosphere, stir at 2700 rpm for 25 min, heat to 63 ℃, stir at 600 rpm for 3 h, filter, wash with n-hexane for 3 times, and place in a 35 ℃, 9 kPa environment for drying for 12 h to obtain silicon carbide hybrid microcapsules; add 12 g of zinc stearate to 480 g of toluene, heat to 73 ℃, stir at 300 rpm for 20 min, add 32 g of USY zeolite with a particle size of 100 nm, ultrasonic disperse at 150 W for 40 min, stir at 300 rpm for 2 h, cool to room temperature, filter, wash with toluene for 2 times, and place in a 50 ℃, 10 kPa environment for drying for 12 h to obtain zinc stearate modified zeolite; add 28 g of the zinc stearate modified zeolite to 120 g of deionized water, ultrasonic disperse at 230 W for 19 min, add 2 g of TFEMA, 8 g of PEGMA (M n 500 g / mol), 0.25 g of MBA, stir at 400 rpm for 30 min, adjust pH value to 5 by adding 10 wt% acetic acid solution, add 0.2 g of V-50, heat to 68 ℃, stir at 300 rpm for 3 h, cool to room temperature, filter, wash with deionized water for 3 times, wash with anhydrous ethanol for 3 times, and place in a 60 ℃, 20 kPa environment for drying for 8 h to obtain zeolite hybrid microcapsules.

[0046] The 20 g of silicon carbide hybrid microcapsules and 8 g of zeolite hybrid microcapsules were added into 220 g of bisphenol A type epoxy resin (epoxy equivalent weight of 230 g / eq), stirred at 700 rpm for 40 min, 160 g of polyamide was slowly added under stirring at 300 rpm, stirred at 400 rpm for 30 min, and vacuum degassing was performed at 12 kPa for 16 min to obtain a coating.

[0047] The 13 g of KH-560 was mixed with 193 g of 95 wt% ethanol solution, and the pH value was adjusted to 4.5 by adding 5 wt% acetic acid solution, and stirring was performed at 350 rpm for 1.5 h to obtain a KH-560 hydrolysate; the pendant line was soaked in 9 wt% sodium hydroxide solution for 3 min, taken out, washed with deionized water for 2 times, soaked in the KH-560 hydrolysate for 40 min, taken out, washed with 90 wt% ethanol solution for 2 times, and dried in an oven preheated to 80℃ for 2 h, taken out, and naturally cooled to complete the pretreatment of the pendant line; the pretreated pendant line was immersed in the coating, taken out at a uniform speed of 5 mm / s, and cured at 45℃ for 80 h to obtain an anti-fatigue coating.

[0048] The prepolymer mixed solution used in this example was prepared according to Preparation Example Two.

[0049] Example Four

[0050] The 95 g of prepolymer mixed solution, 2 g of TFEMA, 6 g of PEGMA (M n of 430 g / mol), 0.2 g of MBA, and 0.1 g of V-65 were mixed under a nitrogen atmosphere, and stirring was performed at 500 rpm for 10 min to obtain an internal phase liquid; the 530 g of dimethyl silicone oil (kinematic viscosity of 55 mm 2 / s at 25℃) and 1.5 g of Span-80 were mixed, and stirring was performed at 500 rpm for 20 min to obtain a dispersion liquid; the internal phase liquid was added into the dispersion liquid under a nitrogen atmosphere, stirring was performed at 2500 rpm for 30 min, the temperature was increased to 65℃, and stirring was performed at 550 rpm for 3.5 h, filtration was performed, n-hexane washing was performed for 3 times, and drying was performed at 38℃ under an environment of 8 kPa for 10 h to obtain silicon carbide hybrid microcapsules; 8 g of zinc stearate was added into 500 g of toluene, the temperature was increased to 80℃, stirring was performed at 300 rpm for 20 min, 33 g of USY zeolite with a particle size of 100 nm was added, ultrasonic dispersion was performed at 200 W for 32 min, stirring was performed at 350 rpm for 1.5 h, the temperature was cooled to room temperature, filtration was performed, toluene washing was performed for 2 times, and drying was performed at 55℃ under an environment of 15 kPa for 11 h to obtain zinc stearate modified zeolite; 25 g of zinc stearate modified zeolite was added into 130 g of deionized water, ultrasonic dispersion was performed at 250 W for 15 min, 3 g of TFEMA and 6 g of PEGMA (M nThe zeolite hybrid microcapsules were obtained by mixing 23 g of the silicon carbide hybrid microcapsules and 8 g of the zeolite hybrid microcapsules with 200 g of bisphenol A type epoxy resin (epoxy equivalent weight of 210 g / eq), stirring at 680 rpm for 45 min, slowly adding 156 g of polyamide under stirring at 300 rpm, stirring at 400 rpm for 30 min, vacuum degassing at 13 kPa for 18 min, and obtaining a coating.

[0051] The zeolite hybrid microcapsules were obtained by mixing 23 g of the silicon carbide hybrid microcapsules and 8 g of the zeolite hybrid microcapsules with 200 g of bisphenol A type epoxy resin (epoxy equivalent weight of 210 g / eq), stirring at 680 rpm for 45 min, slowly adding 156 g of polyamide under stirring at 300 rpm, stirring at 400 rpm for 30 min, vacuum degassing at 13 kPa for 18 min, and obtaining a coating.

[0052] The KH-560 hydrolysate was obtained by mixing 15 g of KH-560 with 196 g of 96 wt% ethanol solution, adjusting the pH value to 4 by adding a 5 wt% acetic acid solution, and stirring at 400 rpm for 1 h. The pendant line was pre-processed by immersing it in a 9 wt% sodium hydroxide solution for 2 min, taking it out, washing it with deionized water twice, immersing it in the KH-560 hydrolysate for 36 min, taking it out, washing it with an 80 wt% ethanol solution twice, and drying it in an oven preheated to 85°C for 2 h, taking it out, and naturally cooling it. The anti-fatigue coating was obtained by immersing the pre-processed pendant line in the coating, pulling it out at a uniform speed of 5 mm / s, and curing it at 47°C for 75 h.

[0053] The prepolymer mixture used in this example was prepared according to Preparation Example Two.

[0054] Example Five

[0055] The inner phase liquid was obtained by mixing 90 g of the prepolymer mixture, 3 g of TFEMA, 7 g of PEGMA (M n The inner phase liquid was obtained by mixing 90 g of the prepolymer mixture, 3 g of TFEMA, 7 g of PEGMA (M 2Silicon carbide hybrid microcapsules were obtained by mixing 22 g of the silicon carbide hybrid microcapsules and 12 g of the zeolite hybrid microcapsules in 210 g of bisphenol A type epoxy resin (epoxy equivalent weight of 215 g / eq), stirring at 660 rpm for 50 min, slowly adding 153 g of polyamide under stirring at 300 rpm, stirring at 400 rpm for 30 min, and vacuum degassing at 10 kPa for 15 min to obtain a coating. n Zeolite hybrid microcapsules were obtained by mixing 26 g of the zinc stearate modified zeolite in 125 g of deionized water, ultrasonic dispersing at 200 W for 20 min, adding 4 g of TFEMA, 7 g of PEGMA (M

[0056] Silicon carbide hybrid microcapsules were obtained by mixing 22 g of the silicon carbide hybrid microcapsules and 12 g of the zeolite hybrid microcapsules in 210 g of bisphenol A type epoxy resin (epoxy equivalent weight of 215 g / eq), stirring at 660 rpm for 50 min, slowly adding 153 g of polyamide under stirring at 300 rpm, stirring at 400 rpm for 30 min, and vacuum degassing at 10 kPa for 15 min to obtain a coating.

[0057] The pre-treatment of the pendant line was performed by immersing the pendant line in a 10 wt% sodium hydroxide solution for 3 min, taking it out, washing with deionized water for 2 times, immersing in the KH-560 hydrolysis solution for 32 min, taking it out, washing with a 75 wt% ethanol solution for 2 times, and drying in an oven preheated to 80°C for 1.5 h, taking it out, and naturally cooling to complete the pre-treatment of the pendant line.

[0058] The prepolymer mixed solution used in this example was prepared in Preparation Example Three.

[0059] Example Six

[0060] A mixture of 90 g of prepolymer solution, 3 g of TFEMA, 7 g of PEGMA (M n 450 g / mol), 0.25 g of MBA, and 0.15 g of V-65 was mixed under a nitrogen atmosphere, stirred at 500 rpm for 10 min to obtain an internal phase liquid; a mixture of 500 g of dimethyl silicone oil (kinematic viscosity of 50 mm 2 / s at 25 °C) and 1 g of Span-80 was mixed, stirred at 500 rpm for 20 min to obtain a dispersion liquid; the internal phase liquid was added to the dispersion liquid under a nitrogen atmosphere, stirred at 2700 rpm for 20 min, warmed to 60 °C, stirred at 500 rpm for 3 h, filtered, washed with n-hexane 3 times, and dried at 40 °C under a 10 kPa environment for 12 h to obtain the silicon carbide hybrid microcapsule.

[0061] The silicon carbide hybrid microcapsule was added to 210 g of bisphenol A type epoxy resin (epoxy equivalent weight of 215 g / eq), stirred at 660 rpm for 50 min, slowly added to 153 g of polyamide under stirring at 300 rpm, stirred at 400 rpm for 30 min, and vacuum degassed under a 10 kPa environment for 15 min to obtain a coating.

[0062] A mixture of 10 g of KH-560 and 200 g of 95 wt% ethanol solution was mixed, the pH value was adjusted to 5 by adding a 5 wt% acetic acid solution, and stirred at 300 rpm for 2 h to obtain a KH-560 hydrolysis solution; the pendant line was soaked in a 10 wt% sodium hydroxide solution for 3 min, taken out, washed with deionized water 2 times, soaked in the KH-560 hydrolysis solution for 32 min, taken out, washed with a 75 wt% ethanol solution 2 times, placed in an oven preheated to 80 °C for drying for 1.5 h, taken out, and naturally cooled to complete the pretreatment of the pendant line; the pretreated pendant line was immersed in the coating, taken out at a uniform speed of 5 mm / s, and placed in a 40 °C environment for curing for 72 h to obtain an anti-fatigue coating.

[0063] The prepolymer solution used in this example was prepared according to Preparation Example Three.

[0064] Comparative Example One

[0065] The difference between this comparative example and Example Five is that the silicon carbide hybrid microcapsule was not added in the preparation process of the anti-fatigue coating, and the remaining operation steps and reaction conditions were the same as those of Example Five to obtain an anti-fatigue coating.

[0066] Comparative Example Two

[0067] The difference between this comparative example and Example Five is that the V-65 was not added in the preparation process of the silicon carbide microcapsule, and the remaining operation steps and reaction conditions were the same as those of Example Five to obtain an anti-fatigue coating.

[0068] Comparative Example Three

[0069] The difference between the present comparative example and Example 5 is that no modified silicon carbide is added in the preparation of the silicon carbide hybrid microcapsules, and the remaining operation steps and experimental conditions are the same as those of Example 5, to obtain an anti-fatigue coating.

[0070] Comparative Example 4

[0071] The difference between the present comparative example and Example 5 is that the pendant line is not treated with the KH-560 hydrolysis solution, and the remaining operation steps and reaction conditions are the same as those of Example 5, to obtain an anti-fatigue coating.

[0072] Bending fatigue performance test

[0073] The pendant line coated with the anti-fatigue coating prepared in each comparative example and each example is fixed on a bending fatigue testing machine, with a bending radius of 5 mm, a bending angle of ±90°, and a frequency of 30 times / min. Every 100 times, the bending area is checked with a magnifying glass, and the cycle number at which the first coating peeling, penetrating crack or complete rupture occurs is recorded as the bending fatigue life. The results are shown in Table 1.

[0074] Table 1

[0075]

[0076] Friction performance test

[0077] The pendant line coated with the anti-fatigue coating prepared in each example and each comparative example is installed on a fretting wear testing machine, with a stainless steel clamp as the counterpart, a normal load of 10 N, a displacement amplitude of 50 μm, a frequency of 30 Hz, and a continuous running of 100,000 times. At the 1st, 10,000th, 30,000th, 50,000th and 100,000th running, the friction coefficient between the stainless steel clamp and the anti-fatigue coating is recorded, as shown in Table 2. At the 100,000th running, the wear volume of each anti-fatigue coating is measured by a white light interferometer, and the specific wear rate is calculated according to the following formula:

[0078]

[0079] The specific wear rate is calculated, and in this test, the normal load is 10 N, and the total sliding distance is 20 m at the 100,000th running. The specific wear rate of the anti-fatigue coating prepared in each example and comparative example is shown in Table 3.

[0080] Table 2

[0081]

[0082] Table 3

[0083]

[0084] According to Table 1, Table 2 and Table 3, the friction coefficient and specific wear rate of the anti-fatigue coating prepared in Examples 1-5 are smaller than that of Example 6 when the stainless steel clip and the anti-fatigue coating are opposite to run 100,000 times, indicating that the zeolite hybrid microcapsules can form a lubricating film on the friction surface after friction and crushing, reducing the friction coefficient of the friction surface and further improving the local wear resistance of the anti-fatigue coating. Compared with Comparative Example 1, the anti-fatigue coating prepared in Examples 1-5 has smaller friction coefficient and specific wear rate, indicating that adding silicon carbide hybrid microcapsules during the preparation of the anti-fatigue coating can improve the local wear resistance of the anti-fatigue coating. Compared with Comparative Example 2, the anti-fatigue coating prepared in Examples 1-5 can bend synchronously with the pendant line, having good bending fatigue resistance, indicating that adding V-65 in the inner phase liquid can coat a shell layer on the modified silicon carbide, reducing the negative impact of adding rigid modified silicon carbide on the bending fatigue resistance of the anti-fatigue coating and inhibiting the peeling between the anti-fatigue coating and the pendant line. Compared with Comparative Example 3, the anti-fatigue coating prepared in Examples 1-5 has smaller friction coefficient and specific wear rate, indicating that the addition of modified silicon carbide can effectively improve the local wear resistance of the anti-fatigue coating. Compared with Comparative Example 4, the anti-fatigue coating prepared in Examples 1-5 has good bending fatigue resistance and wear resistance, indicating that treating the pendant line with KH-560 hydrolysis liquid can improve the adhesion between the anti-fatigue coating and the pendant line, and the anti-fatigue coating is not prone to peeling from the pendant line during friction and bending.

Claims

1. A method for preparing an anti-fatigue coating for a dropper wire, characterized in that, Includes the following steps: S1. In an inert atmosphere, polycaprolactone diol, dibutyltin dilaurate, and toluene are mixed, then modified silicon carbide is added for dispersion, and toluene diisocyanate is added. The mixture is stirred to obtain a prepolymer mixture. In an inert atmosphere, the prepolymer mixture, trifluoroethyl methacrylate, poly(ethylene glycol) methyl ether methacrylate, N,N'-methylenebisacrylamide, and a free radical initiator are mixed to obtain an inner phase liquid. Dimethyl silicone oil and an emulsifier are mixed to obtain a dispersion. The inner phase liquid is added to the dispersion, stirred for emulsification, and heated for reaction. After filtration, washing, and drying, silicon carbide hybrid microcapsules are obtained. The modified silicon carbide is obtained by treating silicon carbide with 3-hydroxypropyltrimethoxysilane. The silicon carbide hybrid microcapsules are prepared by the following method: in an inert atmosphere, 90-100 parts by weight of prepolymer mixture, 2-4 parts by weight of TFEMA, 5-7 parts by weight of PEGMA, 0.2-0.3 parts by weight of MBA, and 0.1-0.2 parts by weight of 2,2'-azobis(2,4-dimethylpentanonitrile) were mixed to obtain an inner phase liquid; 500-550 parts by weight of dimethyl silicone oil and 1-2 parts by weight of Span-80 were mixed to obtain a dispersion; under an inert atmosphere, the inner phase liquid was added to the dispersion, stirred at 2500-2700 rpm for 20-30 min, heated to 60-65℃, stirred at 500-600 rpm for 3-4 h, filtered, washed with n-hexane, and dried at 30-40℃ and 7-10 kPa for 8-12 h to obtain silicon carbide hybrid microcapsules; the M of the PEGMA n The dimethyl silicone oil has a kinematic viscosity of 50-60 mmHg at 25°C and a viscosity of 400-450 g / mol. 2 / s; S2. Disperse silicon carbide hybrid microcapsules in bisphenol A type epoxy resin, slowly add polyamide under continuous stirring and mix well, then degas under vacuum to obtain coating. S3. Apply the coating to the pretreated drop wires and cure to obtain an anti-fatigue coating.

2. The method for preparing an anti-fatigue coating for a dropper wire according to claim 1, characterized in that, The modified silicon carbide is prepared by the following method: 8-10 parts by weight of HPTMS and 200-220 parts by weight of 93-97 wt% ethanol solution are mixed, acetic acid solution is added to adjust the pH to 4-5, and the mixture is stirred at 300-400 rpm for 1-2 hours. Then, 20-25 parts by weight of hydrophilic silicon carbide are added, and the mixture is stirred at 1000-1200 rpm for 15-25 minutes. The temperature is raised to 60-70℃, and the mixture is stirred at 300-400 rpm for 3-4 hours. After filtration and washing with anhydrous ethanol, the mixture is placed at 50-60℃ and 10-20 kPa. The modified silicon carbide is obtained by drying in an environment for 10-12 hours. The hydrophilic silicon carbide is prepared by mixing 295-303 parts by weight of 65-70 wt% nitric acid solution and 98-101 parts by weight of 30-35 wt% hydrogen peroxide solution, adding 28-31 parts by weight of silicon carbide, heating to 73-77℃, stirring at 300-400 rpm for 3-4 hours, filtering, washing with deionized water until the pH of the washing solution is 7, and drying in an environment of 50-60℃ and 10-20 kPa for 8-10 hours to obtain hydrophilic silicon carbide.

3. The method for preparing an anti-fatigue coating for a dropper wire according to claim 2, characterized in that, The prepolymer mixture is prepared as follows: In an inert atmosphere, 62-68 parts by weight of polycaprolactone diol, 0.6-0.8 parts by weight of DBTDL, and 130-140 parts by weight of toluene are mixed. 15-20 parts by weight of modified silicon carbide are added, and the mixture is stirred at 900-1000 rpm for 20-25 minutes. The temperature is raised to 70-80°C, and 10-13 parts by weight of TDI are slowly added under continuous stirring. The mixture is stirred at 300-400 rpm for 2-3 hours to obtain the prepolymer mixture. The M of the polycaprolactone diol... n It is 2000-2200 g / mol.

4. The method for preparing an anti-fatigue coating for a dropper wire according to claim 1, characterized in that, The coating also includes zeolite hybrid microcapsules, which are prepared as follows: 23-28 parts by weight of zinc stearate-modified zeolite are added to 100-130 parts by weight of deionized water and ultrasonically dispersed at 200-250W for 15-20 min. Then, 2-4 parts by weight of TFEMA, 5-8 parts by weight of PEGMA, and 0.2-0.3 parts by weight of MBA are added and mixed. Acetic acid solution is added dropwise to adjust the pH to 4-5. Then, 0.1-0.2 parts by weight of 2,2'-azobis(2-methyl-2-imidazoline) dihydrochloride is added. The mixture is heated to 65-70℃ and stirred at 300-400 rpm for 2-3 h. After cooling, the mixture is filtered, washed with deionized water and anhydrous ethanol, and dried at 50-60℃ and 10-20 kPa for 8-12 h to obtain the zeolite hybrid microcapsules. The PEGMA M... n It is 450-500 g / mol.

5. The method for preparing an anti-fatigue coating for a dropper wire according to claim 4, characterized in that, The zinc stearate-modified zeolite was prepared by the following method: 8-12 parts by weight of zinc stearate were dissolved in 480-500 parts by weight of toluene at 70-80℃, 30-35 parts by weight of zeolite were added, and the mixture was ultrasonically dispersed at 150-200W for 30-40 min, stirred at 300-400 rpm for 1-2 h, filtered, washed with toluene, and dried in an environment of 50-60℃ and 10-20 kPa for 10-12 h to obtain zinc stearate-modified zeolite; the zeolite was USY zeolite.

6. The method for preparing an anti-fatigue coating for a dropper wire according to claim 1, characterized in that, In step S2, 18-23 parts by weight of silicon carbide hybrid microcapsules and 0-12 parts by weight of zeolite hybrid microcapsules are added to 200-220 parts by weight of bisphenol A type epoxy resin, stirred at 600-700 rpm for 40-50 min, and 150-160 parts by weight of polyamide are slowly added and mixed under continuous stirring. The mixture is then placed in a 10-15 kPa environment for degassing for 15-20 min to obtain the coating. The epoxy equivalent of the bisphenol A type epoxy resin is 210-230 g / eq.

7. The method for preparing an anti-fatigue coating for a dropper wire according to claim 1, characterized in that, The dropper wire is pretreated as follows: Immerse the dropper wire in an 8-10 wt% sodium hydroxide solution for 2-4 minutes, remove it, wash it with deionized water, then immerse it in γ-glycidyl etheroxypropyltrimethoxysilane hydrolysate for 30-40 minutes, wash it with a 70-90 wt% ethanol solution, dry it in an environment of 80-90℃ for 1-2 hours, and cool it to complete the pretreatment of the dropper wire.

8. The method for preparing an anti-fatigue coating for a dropper wire according to claim 7, characterized in that, The γ-glycidyl etheroxypropyltrimethoxysilane hydrolysate is prepared by the following method: 10-15 parts by weight of KH-560 and 193-202 parts by weight of 95-97 wt% ethanol solution are mixed, acetic acid solution is added to adjust the pH to 4-5, and the mixture is stirred at 300-400 rpm for 1-2 hours to obtain the γ-glycidyl etheroxypropyltrimethoxysilane hydrolysate.

9. The method for preparing an anti-fatigue coating for a dropper wire according to claim 1, characterized in that, In step S3, the pretreated dropper wire is immersed in the coating and pulled up to be removed. It is then placed in an environment of 40-50℃ for 72-80 hours to cure, thus obtaining an anti-fatigue coating.

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