High-strength wear-resistant fastener and preparation process thereof

Abstract

The invention discloses a high-strength wear-resistant fastener and a preparation process thereof, and relates to the technical field of fastener preparation. According to the preparation method, dipentaerythritol and 1, 1, 1-trifluoro-2, 3-epoxypropane are taken as raw materials to prepare polyfunctional fluorine-containing polyol, then double-bond-containing polyfunctional polyurethane acrylate and a macromolecular photoinitiator are respectively prepared through the polyfunctional fluorine-containing polyol, and molybdenum disulfide is modified through 2, 4-dimercapto-5, 6-diaminopyrimidine, so that the photoinitiator is prepared. The preparation method comprises the following steps: preparing functional molybdenum disulfide, blending double-bond-containing polyfunctional polyurethane acrylate, the functional molybdenum disulfide and a macromolecular photoinitiator to obtain composite polyfunctional polyurethane acrylate, mixing the composite polyfunctional polyurethane acrylate with an auxiliary agent to obtain a wear-resistant coating, coating the surface of a copper-plated fastener with the wear-resistant coating, and performing ultraviolet curing to obtain the wear-resistant copper-plated fastener. And the formed wear-resistant coating has the properties of high wear resistance, high impact strength and the like.

Description

Technical Field

[0001] This invention relates to the field of fastener manufacturing technology, specifically a high-strength wear-resistant fastener and its manufacturing process. Background Technology

[0002] Fasteners are mechanical parts used for fastening connections and are widely used in machinery, chemical industry, metallurgy, electronics and other fields. There are many types of fasteners with different properties, and they are characterized by standardization, serialization and generalization. Therefore, fasteners with existing national standards are called standard fasteners or standard parts.

[0003] CN116676038A discloses a wear-resistant fastener material and its preparation method. It uses Q235A carbon steel as the matrix and coats the matrix surface with modified polybenzimidazole as a protective layer, which makes the fastener have better high temperature resistance and corrosion resistance. However, the bonding force between the organic coating and the Q235A carbon steel matrix is ​​poor and it is easy to fall off, which affects the use effect and service life of the fastener.

[0004] Therefore, we propose a high-strength wear-resistant fastener and its manufacturing process. The fastener surface is first copper-plated and then coated with a wear-resistant coating to form a wear-resistant layer, which makes the fastener stronger and more wear-resistant. Summary of the Invention

[0005] The purpose of this invention is to provide a high-strength wear-resistant fastener and its manufacturing process to solve the problems raised in the prior art.

[0006] To achieve the above objectives, the present invention provides the following technical solution: a manufacturing process for high-strength wear-resistant fasteners, comprising the following steps: Take the fasteners and sequentially perform pickling, cleaning, drying, and copper plating to form a copper plating layer. Then, apply a wear-resistant coating and cure with ultraviolet light to form a wear-resistant coating, thus obtaining high-strength wear-resistant fasteners.

[0007] Furthermore, the fastener is made of titanium alloy; The thickness of the copper plating layer is 5~8μm; The thickness of the wear-resistant coating is 6~12μm.

[0008] Furthermore, the pickling solution used for pickling includes the following components by mass: 300~500 g / L hydrochloric acid, 30~50 g / L sodium dodecyl sulfate, and 2~6 g / L imidazoline quaternary ammonium salt; The solvent for the pickling solution is deionized water; The hydrochloric acid has a mass fraction of 20%.

[0009] Furthermore, the pickling process conditions are: temperature 20~40℃, time 6~10min.

[0010] Furthermore, the copper plating solution used for copper plating includes the following components by mass: copper sulfate pentahydrate 140~180g / L, sulfuric acid 40~100g / L, sodium polydisulfide dipropanesulfonate 2~6mg / L, and polyethylene glycol 200~400mg / L. The solvent for the copper plating solution is deionized water; The sulfuric acid has a mass fraction of 98%.

[0011] Furthermore, the copper plating process conditions are: temperature 20~40℃, time 50~70min, current density 0.5~1.5A / dm³. 2 .

[0012] Furthermore, the UV curing process conditions are as follows: UV lamp power 500~1000W, curing time 1~10min, curing distance 10~20cm.

[0013] Furthermore, the wear-resistant coating is prepared by the following process: Mix the multifunctional polyurethane acrylate, diluent, leveling agent, dispersant, defoamer, and wetting agent, stir evenly, heat to 40~50℃, and stir for 30~50 minutes to obtain the wear-resistant coating.

[0014] Furthermore, the mass ratio of the composite multifunctional polyurethane acrylate, diluent, leveling agent, dispersant, defoamer, and wetting agent is (60~80):(40~50):(1~3):(3~5):(1~3):(1~3).

[0015] Furthermore, the diluent is one or a mixture of ethylene glycol ethyl ether acetate, trimethylolpropane triacrylate, and propylene glycol methyl ether acetate; The leveling agent is one or a mixture of BYK-354, BYK-390, and BYK-333; The dispersant is one or a mixture of polyethylene glycol, polypropylene glycol, and polyether-modified silicone oil; The defoamer is one or a mixture of two of BYK-070 and BYK-065; The wetting agent is one or a mixture of sodium dodecylbenzenesulfonate, fatty alcohol polyoxyethylene ether, and glycerin.

[0016] Furthermore, the composite multifunctional polyurethane acrylate is prepared by the following process: Step 1: Mix isophorone diisocyanate, bisphenol A, dioxane, and dibutyltin dilaurate to obtain a prepolymer. Then add hydroxyethyl acrylate, stir evenly, and heat in an oil bath under nitrogen atmosphere. Then raise the temperature to 60-65℃, add a multifunctional fluorinated polyol solution, and react at a constant temperature of 60-65℃ for 4-6 hours under nitrogen atmosphere. Rotary evaporate to obtain polyurethane acrylate with double bonds. Step 2: Mix the polyurethane acrylate containing double bonds, functionalized molybdenum disulfide, and macromolecular photoinitiator, and stir until homogeneous to obtain a composite polyurethane acrylate.

[0017] Furthermore, in step 1, the mass ratio of isophorone diisocyanate, bisphenol A, dioxane, dibutyltin dilaurate, hydroxyethyl acrylate, and polyfunctional fluorinated polyol solution is 10: (0.02~0.04): (23~26): (0.04~0.06): (14~16): (14~16).

[0018] Furthermore, in step 1, the multifunctional fluorinated polyol solution is prepared by mixing multifunctional fluorinated polyol and dioxane at a mass ratio of 1:(1.1~1.5).

[0019] Furthermore, in step 1, the process conditions for the oil bath heating reaction are: temperature 33~37℃, time 4.5~5.5h; In step 1, the rotary evaporation process conditions are: temperature 50~70℃, time 40~60min.

[0020] Furthermore, in step 2, the mass ratio of the polyurethane acrylate containing double bonds and multifunctional polyurethane, functionalized molybdenum disulfide, and macromolecular photoinitiator is 10:(1~3):(0.1~0.5).

[0021] Furthermore, the multifunctional fluorinated polyol is prepared by the following process: Dipentaerythritol and dimethyl sulfoxide were mixed and stirred until homogeneous. KOH (potassium hydroxide) was added, and the mixture was heated under a nitrogen atmosphere. 1,1,1-trifluoro-2,3-epoxypropane was added, and the mixture was kept at a constant temperature for 1-2 hours. Then, the mixture was desolvated under vacuum to obtain a multifunctional fluorinated polyol.

[0022] Furthermore, the mass ratio of dipentaerythritol, dimethyl sulfoxide, KOH, and 1,1,1-trifluoro-2,3-epoxypropane is 10:(1.0~1.5):(0.08~0.10):(20~25).

[0023] Furthermore, the process conditions for the heating reaction are: temperature 90~100℃, time 1.5~2.5h; The vacuum degree during vacuum desolvation is -0.09 to -0.07 MPa.

[0024] Furthermore, the functionalized molybdenum disulfide is prepared by the following process: 2,4-dimercapto-5,6-diaminopyrimidine and dimethyl sulfoxide were mixed and subjected to a first ultrasonic treatment. Then, molybdenum disulfide powder was added and stirred at 500-600 r / min for 20-24 h. A second ultrasonic treatment was then performed, followed by centrifugation to precipitate the mixture, thus obtaining functionalized molybdenum disulfide.

[0025] Furthermore, the mass ratio of 2,4-dimercapto-5,6-diaminopyrimidine, dimethyl sulfoxide, and molybdenum disulfide powder is 10:(55~65):(0.5~0.7).

[0026] Furthermore, the process conditions for the first ultrasonic treatment are: frequency 50~100kHz, time 25~35min; The process conditions for the second ultrasonic treatment are: frequency 50~100kHz, 10~12h.

[0027] Furthermore, the centrifugation process conditions are: rotation speed 1500~2500 r / min, time 70~90 min.

[0028] Furthermore, the preparation process of the macromolecular photoinitiator is as follows: Isophorone diisocyanate, dibutyltin dilaurate, and polyethylene glycol were mixed and stirred to react. Then, a photoinitiator and a multifunctional fluorinated polyol were added, and the mixture was heated and stirred to react. The mixture was then distilled under reduced pressure to obtain a macromolecular photoinitiator.

[0029] Furthermore, the mass ratio of isophorone diisocyanate, dibutyltin dilaurate, polyethylene glycol, photoinitiator, and multifunctional fluorinated polyol is 10:(0.10~0.15):(8~12):(4~6):(1.5~2.5).

[0030] Furthermore, the photoinitiator is one or both of photoinitiator 2959 and photoinitiator 1173.

[0031] Furthermore, the process conditions for the stirring reaction are: temperature 20~30℃, time 2~4h; The process conditions for heating and stirring reaction are: temperature 45~55℃, time 2~6h.

[0032] Compared with the prior art, the beneficial effects of the present invention are: 1. Molybdenum disulfide has good wear resistance and lubrication properties, and its coefficient of friction is lower than that of metals. When added to coatings as a coating layer, it can significantly reduce wear on the contact surface and improve the wear resistance of the substrate. However, molybdenum disulfide is prone to stacking in the coating system, resulting in uneven dispersion. Therefore, by reacting the thiol group of 2,4-dimercapto-5,6-diaminopyrimidine with molybdenum disulfide, an amino group is introduced on the surface of molybdenum disulfide, while retaining another thiol group, to obtain molybdenum disulfide containing thiol and amino groups, which is referred to as functionalized molybdenum disulfide.

[0033] 2. A multifunctional fluorinated polyol is obtained by reacting the hydroxyl group of dipentaerythritol with 1,1,1-trifluoro-2,3-epoxypropane under alkaline conditions to introduce fluorine. A prepolymer with a hydroxyl group at one end and an isocyanate group at the other end is obtained by reacting the isocyanate group of isophorone diisocyanate with the hydroxyl group of bisphenol A. Then, a nucleophilic addition reaction is carried out with the hydroxyl group of hydroxyethyl acrylate to introduce a double bond. Finally, the prepolymer reacts with the hydroxyl group of the multifunctional fluorinated polyol to obtain a fluorinated multifunctional polyurethane acrylate with a double bond at the end. The chain is extended by reacting isophorone diisocyanate with polyethylene glycol, followed by the addition of a photoinitiator and a multifunctional fluorinated polyol. The hydroxyl groups of the two react with the isocyanate groups to obtain a macromolecular photoinitiator. Commercially available photoinitiators are mostly small molecule compounds, while polyurethane coatings are macromolecular polymers. The difference in molecular weight between the two is large, resulting in poor compatibility and easy precipitation. Therefore, the photoinitiator is introduced into the end of the polyurethane molecular chain to improve its compatibility with the coating system, reduce phase separation, improve curing efficiency, and enhance the wear-resistant coating performance. Next, a multifunctional polyurethane acrylate containing fluorine and terminal double bonds, functionalized molybdenum disulfide, and a macromolecular photoinitiator are blended to obtain a composite multifunctional polyurethane acrylate. This is then mixed with various additives to obtain a wear-resistant coating. This coating system contains thiol groups, double bonds, fluorine, and amino groups. Under the action of the macromolecular photoinitiator, the thiol groups and double bonds react under ultraviolet light irradiation to form a wear-resistant coating. Fluorine has hydrophobicity and low surface energy, making it difficult to adhere to other substances, which can reduce adhesive wear during friction and improve the wear resistance of fasteners. Amino groups can react with Cu on the surface of the copper plating layer. 2+ Complexation enhances adhesion to the copper layer; In addition, this coating system has multiple functions. Compared with low-functionality coating systems, the cross-linked network formed after curing is more dense and has higher hardness, which can significantly improve impact resistance and scratch resistance.

[0034] 3. Due to the high coefficient of friction of titanium alloy surfaces, they are prone to "seizing" with other metals, causing damage to fasteners. In addition, titanium alloys have low surface energy and poor adhesion to coating systems. Therefore, copper plating is first applied to the surface of titanium alloys. The copper plating layer has good plasticity and absorbs stress through slight deformation during friction, significantly reducing friction and wear. It works synergistically with molybdenum disulfide in the coating to improve the fastener's potential sticking problem, and comprehensively improve the fastener's wear resistance and strength. Detailed Implementation

[0035] The technical solutions in the embodiments of the present invention will be clearly and completely described below. Obviously, the described embodiments are only some embodiments of the present invention, and not all embodiments. Based on the embodiments of the present invention, all other embodiments obtained by those skilled in the art without creative effort are within the scope of protection of the present invention.

[0036] In the following specific implementation, The fasteners are made of titanium alloy TC4 and are sourced from Jiangxi Jiangye Precision Fastener Manufacturing Co., Ltd. Sulfuric acid, with a mass fraction of 98%; Hydrochloric acid, with a mass fraction of 20%; Polyethylene glycol, with an average molecular weight of 4000; The diluent is ethylene glycol ethyl ether acetate; The leveling agent is BYK-354; The dispersant is polyether-modified silicone oil, model SC-12847; The defoamer is BYK-070; The wetting agent is sodium dodecylbenzenesulfonate; Molybdenum disulfide powder with an average particle size of 5 μm; The photoinitiator is photoinitiator 2959; Polyether polyol with a functionality of 2 and an average molecular weight of 3000.

[0037] Example 1: A manufacturing process for a high-strength wear-resistant fastener, comprising the following steps: (1) Preparation of composite multifunctional polyurethane acrylate: Dipentaerythritol and dimethyl sulfoxide were mixed and stirred until homogeneous. KOH was added, and the mixture was heated under a nitrogen atmosphere. 1,1,1-trifluoro-2,3-epoxypropane was then added, and the mixture was reacted at a constant temperature for 2 hours. The solution was then removed under vacuum to obtain a multifunctional fluorinated polyol. The mass ratio of dipentaerythritol, dimethyl sulfoxide, KOH, and 1,1,1-trifluoro-2,3-epoxypropane was 10:1.5:0.10:25. The heating reaction conditions were: temperature 100℃, time 2.5 hours; and the vacuum degree during the removal of the solution was -0.07 MPa. 2,4-Dimercapto-5,6-diaminopyrimidine and dimethyl sulfoxide were mixed and subjected to a first ultrasonic treatment. Then, molybdenum disulfide powder was added, and the mixture was stirred at 600 r / min for 24 h. A second ultrasonic treatment was then performed, followed by centrifugation to precipitate the mixture, thus obtaining functionalized molybdenum disulfide. The mass ratio of 2,4-dimercapto-5,6-diaminopyrimidine, dimethyl sulfoxide, and molybdenum disulfide powder was 10:65:0.7. The process conditions for the first ultrasonic treatment were: frequency 100 kHz, time 35 min; the process conditions for the second ultrasonic treatment were: frequency 100 kHz, time 12 h; and the process conditions for centrifugation were: speed 2500 r / min, time 90 min. Isophorone diisocyanate, dibutyltin dilaurate, and polyethylene glycol were mixed and stirred to react. Then, photoinitiator 2959 and a multifunctional fluorinated polyol were added, and the mixture was heated and stirred to react. The mixture was then distilled under reduced pressure to obtain a macromolecular photoinitiator. The mass ratio of isophorone diisocyanate, dibutyltin dilaurate, polyethylene glycol, photoinitiator, and multifunctional fluorinated polyol was 10:0.15:12:6:2.5. The stirring reaction conditions were: temperature 30℃, time 4h; the heating and stirring reaction conditions were: temperature 55℃, time 6h. A multifunctional fluorinated polyol solution was prepared by mixing a multifunctional fluorinated polyol with a dioxane at a mass ratio of 1:1.5. Step 1: Mix isophorone diisocyanate, bisphenol A, dioxane, and dibutyltin dilaurate to obtain a prepolymer. Add hydroxyethyl acrylate, stir until homogeneous, and react in an oil bath under nitrogen protection. Then, raise the temperature to 65°C, add a multifunctional fluorinated polyol solution, and react at a constant temperature of 65°C for 6 hours under nitrogen protection. Rotary evaporate to obtain a multifunctional polyurethane acrylate containing double bonds. Step 2: Mix the multifunctional polyurethane acrylate containing double bonds, functionalized molybdenum disulfide, and a macromolecular photoinitiator, and stir until homogeneous to obtain a composite multifunctional polyurethane acrylate. Ester; In step 1, the mass ratio of isophorone diisocyanate, bisphenol A, dioxane, dibutyltin dilaurate, hydroxyethyl acrylate, and polyfunctional fluorinated polyol solution is 10:0.04:26:0.06:16:16; In step 1, the oil bath heating reaction conditions are: temperature 37℃, time 5.5h; In step 1, the rotary evaporation process conditions are: temperature 70℃, time 60min; In step 2, the mass ratio of double-bond polyfunctional polyurethane acrylate, functionalized molybdenum disulfide, and macromolecular photoinitiator is 10:3:0.5; (2) Preparation of wear-resistant coatings: The composite multifunctional polyurethane acrylate, ethylene glycol ethyl ether acetate, leveling agent BYK-354, polyether modified silicone oil, defoamer BYK-070, and sodium dodecylbenzene sulfonate were mixed in a mass ratio of 80:50:3:5:3:3, stirred evenly, heated to 50℃, and stirred for 50 minutes to obtain a wear-resistant coating. (3) Preparation of high-strength wear-resistant fasteners: Fasteners are subjected to pickling, cleaning, drying, and copper plating in sequence to form an 8μm copper plating layer. A wear-resistant coating is then applied, followed by UV curing to form a 12μm wear-resistant coating, resulting in high-strength, wear-resistant fasteners. The pickling solution used for pickling comprises the following components: 500g / L hydrochloric acid, 50g / L sodium dodecyl sulfate, and 6g / L imidazoline quaternary ammonium salt. The solvent for the pickling solution is deionized water. The pickling process conditions are: temperature 40℃, time 10min. The copper plating solution used for copper plating comprises the following components: 180g / L copper sulfate pentahydrate, 100g / L sulfuric acid, 6mg / L sodium polydithiopropanesulfonate, and 400mg / L polyethylene glycol. The solvent for the copper plating solution is deionized water. The copper plating process conditions are: temperature 40℃, time 70min, and current density 1.5A / dm³. 2 The UV curing process conditions are: UV lamp power 1000W, curing time 10min, curing distance 20cm.

[0038] Example 2: A manufacturing process for a high-strength wear-resistant fastener, comprising the following steps: (1) Preparation of composite multifunctional polyurethane acrylate: Dipentaerythritol and dimethyl sulfoxide were mixed and stirred until homogeneous. KOH was added, and the mixture was heated under a nitrogen atmosphere. 1,1,1-trifluoro-2,3-epoxypropane was then added, and the mixture was reacted at a constant temperature for 1.5 hours. The mixture was then desolvated under vacuum to obtain a multifunctional fluorinated polyol. The mass ratio of dipentaerythritol, dimethyl sulfoxide, KOH, and 1,1,1-trifluoro-2,3-epoxypropane was 10:1.3:0.09:22. The heating reaction conditions were: temperature 95℃, time 2.0 hours; and the vacuum degree during desolvation was -0.08 MPa. 2,4-Dimercapto-5,6-diaminopyrimidine and dimethyl sulfoxide were mixed and subjected to a first ultrasonic treatment. Then, molybdenum disulfide powder was added, and the mixture was stirred at 550 r / min for 22 h. A second ultrasonic treatment was then performed, followed by centrifugation to precipitate the mixture, thus obtaining functionalized molybdenum disulfide. The mass ratio of 2,4-dimercapto-5,6-diaminopyrimidine, dimethyl sulfoxide, and molybdenum disulfide powder was 10:60:0.6. The process conditions for the first ultrasonic treatment were: frequency 70 kHz, time 30 min; the process conditions for the second ultrasonic treatment were: frequency 80 kHz, time 11 h; and the process conditions for centrifugation were: speed 2000 r / min, time 80 min. Isophorone diisocyanate, dibutyltin dilaurate, and polyethylene glycol were mixed and stirred to react. Then, photoinitiator 2959 and a multifunctional fluorinated polyol were added, and the mixture was heated and stirred to react. The mixture was then distilled under reduced pressure to obtain a macromolecular photoinitiator. The mass ratio of isophorone diisocyanate, dibutyltin dilaurate, polyethylene glycol, photoinitiator, and multifunctional fluorinated polyol was 10:0.13:10:5:2.0. The stirring reaction conditions were: temperature 25℃, time 3h; the heating and stirring reaction conditions were: temperature 50℃, time 4h. A multifunctional fluorinated polyol solution was prepared by mixing a multifunctional fluorinated polyol with a dioxane at a mass ratio of 1:1.3. Step 1: Mix isophorone diisocyanate, bisphenol A, dioxane, and dibutyltin dilaurate to obtain a prepolymer. Add hydroxyethyl acrylate, stir until homogeneous, and react in an oil bath under nitrogen protection. Then, raise the temperature to 62°C, add a multifunctional fluorinated polyol solution, and react at a constant temperature of 62°C for 5 hours under nitrogen protection. Rotary evaporate to obtain a multifunctional polyurethane acrylate containing double bonds. Step 2: Mix the multifunctional polyurethane acrylate containing double bonds, functionalized molybdenum disulfide, and a macromolecular photoinitiator, and stir until homogeneous to obtain a composite multifunctional polyurethane acrylate. Ester; In step 1, the mass ratio of isophorone diisocyanate, bisphenol A, dioxane, dibutyltin dilaurate, hydroxyethyl acrylate, and polyfunctional fluorinated polyol solution is 10:0.03:25:0.05:15:15; In step 1, the oil bath heating reaction conditions are: temperature 35℃, time 5.0h; In step 1, the rotary evaporation process conditions are: temperature 60℃, time 50min; In step 2, the mass ratio of double-bond polyfunctional polyurethane acrylate, functionalized molybdenum disulfide, and macromolecular photoinitiator is 10:2:0.3; (2) Preparation of wear-resistant coatings: The composite multifunctional polyurethane acrylate, ethylene glycol ethyl ether acetate, leveling agent BYK-354, polyether modified silicone oil, defoamer BYK-070, and sodium dodecylbenzene sulfonate were mixed in a mass ratio of 70:45:2:4:2:2, stirred evenly, heated to 45℃, and stirred for 40 minutes to obtain a wear-resistant coating. (3) Preparation of high-strength wear-resistant fasteners: Fasteners are subjected to pickling, cleaning, drying, and copper plating in sequence to form a 7μm copper plating layer. A wear-resistant coating is then applied, followed by UV curing to form an 8μm wear-resistant coating, resulting in high-strength, wear-resistant fasteners. The pickling solution used for pickling comprises the following components: 400g / L hydrochloric acid, 40g / L sodium dodecyl sulfate, and 4g / L imidazoline quaternary ammonium salt. The solvent for the pickling solution is deionized water. The pickling process conditions are: temperature 30℃, time 8min. The copper plating solution used for copper plating comprises the following components: 160g / L copper sulfate pentahydrate, 70g / L sulfuric acid, 4mg / L sodium polydithiopropanesulfonate, and 300mg / L polyethylene glycol. The solvent for the copper plating solution is deionized water. The copper plating process conditions are: temperature 30℃, time 60min, and current density 1.0A / dm³. 2 The UV curing process conditions are: UV lamp power 800W, curing time 5min, curing distance 15cm.

[0039] Example 3: A manufacturing process for a high-strength wear-resistant fastener, comprising the following steps: (1) Preparation of composite multifunctional polyurethane acrylate: Dipentaerythritol and dimethyl sulfoxide were mixed and stirred until homogeneous. KOH was added, and the mixture was heated under a nitrogen atmosphere. 1,1,1-trifluoro-2,3-epoxypropane was then added, and the mixture was reacted at a constant temperature for 1 hour. The solution was then removed under vacuum to obtain a multifunctional fluorinated polyol. The mass ratio of dipentaerythritol, dimethyl sulfoxide, KOH, and 1,1,1-trifluoro-2,3-epoxypropane was 10:1.0:0.08:20. The heating reaction conditions were: temperature 90℃, time 1.5 hours; and the vacuum degree during the removal of the solution was -0.09 MPa. 2,4-Dimercapto-5,6-diaminopyrimidine and dimethyl sulfoxide were mixed and subjected to a first ultrasonic treatment. Then, molybdenum disulfide powder was added, and the mixture was stirred at 500 r / min for 20 h. A second ultrasonic treatment was then performed, followed by centrifugation to precipitate the mixture, thus obtaining functionalized molybdenum disulfide. The mass ratio of 2,4-dimercapto-5,6-diaminopyrimidine, dimethyl sulfoxide, and molybdenum disulfide powder was 10:55:0.5. The process conditions for the first ultrasonic treatment were: frequency 50 kHz, time 25 min; the process conditions for the second ultrasonic treatment were: frequency 50 kHz, time 10 h; and the process conditions for centrifugation were: speed 1500 r / min, time 70 min. Isophorone diisocyanate, dibutyltin dilaurate, and polyethylene glycol were mixed and stirred to react. Then, photoinitiator 2959 and a multifunctional fluorinated polyol were added, and the mixture was heated and stirred to react. The mixture was then distilled under reduced pressure to obtain a macromolecular photoinitiator. The mass ratio of isophorone diisocyanate, dibutyltin dilaurate, polyethylene glycol, photoinitiator, and multifunctional fluorinated polyol was 10:0.10:8:4:1.5. The stirring reaction conditions were: temperature 20℃, time 2h; the heating and stirring reaction conditions were: temperature 45℃, time 2h. A multifunctional fluorinated polyol solution was prepared by mixing a multifunctional fluorinated polyol with a dioxane at a mass ratio of 1:1.1. Step 1: Mix isophorone diisocyanate, bisphenol A, dioxane, and dibutyltin dilaurate to obtain a prepolymer. Add hydroxyethyl acrylate, stir until homogeneous, and react in an oil bath under nitrogen protection. Then, raise the temperature to 60°C, add a multifunctional fluorinated polyol solution, and react at a constant temperature of 60°C for 4 hours under nitrogen protection. Rotary evaporate to obtain a multifunctional polyurethane acrylate containing double bonds. Step 2: Mix the multifunctional polyurethane acrylate containing double bonds, functionalized molybdenum disulfide, and a macromolecular photoinitiator, and stir until homogeneous to obtain a composite multifunctional polyurethane acrylate. Ester; In step 1, the mass ratio of isophorone diisocyanate, bisphenol A, dioxane, dibutyltin dilaurate, hydroxyethyl acrylate, and polyfunctional fluorinated polyol solution is 10:0.02:23:0.04:14:14; In step 1, the oil bath heating reaction conditions are: temperature 33℃, time 4.5h; In step 1, the rotary evaporation process conditions are: temperature 50℃, time 40min; In step 2, the mass ratio of double-bond polyfunctional polyurethane acrylate, functionalized molybdenum disulfide, and macromolecular photoinitiator is 10:1:0.1; (2) Preparation of wear-resistant coatings: The composite multifunctional polyurethane acrylate, ethylene glycol ethyl ether acetate, leveling agent BYK-354, polyether modified silicone oil, defoamer BYK-070, and sodium dodecylbenzene sulfonate were mixed in a mass ratio of 60:40:1:3:1:1, stirred evenly, heated to 40℃, and stirred for 30 minutes to obtain a wear-resistant coating. (3) Preparation of high-strength wear-resistant fasteners: Fasteners are subjected to pickling, cleaning, drying, and copper plating in sequence to form a 5μm copper plating layer. A wear-resistant coating is then applied, followed by UV curing to form a 6μm wear-resistant coating, resulting in high-strength, wear-resistant fasteners. The pickling solution used for pickling comprises the following components: 300g / L hydrochloric acid, 30g / L sodium dodecyl sulfate, and 2g / L imidazoline quaternary ammonium salt. The solvent for the pickling solution is deionized water. The pickling process conditions are: temperature 20℃, time 6min. The copper plating solution used for copper plating comprises the following components: 140g / L copper sulfate pentahydrate, 40g / L sulfuric acid, 2mg / L sodium polydithiopropanesulfonate, and 200mg / L polyethylene glycol. The solvent for the copper plating solution is deionized water. The copper plating process conditions are: temperature 20℃, time 50min, and current density 0.5A / dm³. 2 The UV curing process conditions are: UV lamp power 500W, curing time 1min, curing distance 10cm.

[0040] Comparative Example 1: Compared with Example 1, the multifunctional fluorinated polyol was replaced with a polyether polyol with a functionality of 2, while the other conditions remained unchanged.

[0041] Comparative Example 2: Compared with Example 1, the macromolecular photoinitiator was replaced with photoinitiator 2959, while the other conditions remained unchanged.

[0042] Comparative Example 3: Compared with Example 1, molybdenum disulfide was not functionalized, no macromolecular initiator was added, UV curing was replaced with high-temperature curing, the curing temperature was set to 70°C, the curing time was set to 2 hours, and the other conditions remained unchanged.

[0043] Comparative Example 4: Compared with Example 1, the multifunctional fluorinated polyol was replaced with a polyether polyol with a functionality of 2, and the macromolecular photoinitiator was replaced with photoinitiator 2959, while the other conditions remained unchanged.

[0044] Experiment: The high-strength wear-resistant fasteners obtained in the examples and comparative examples were tested for various properties; Tensile strength test: The tensile strength of the obtained high-strength wear-resistant fasteners was tested according to GB / T 228.1-2021 Part 1: Room temperature test method; Wear resistance test: Record the mass of the high-strength wear-resistant fastener before the test, and conduct a wear test on it in accordance with GB / T 12444-2006. Record the mass after the test and calculate the wear rate. Wear rate = (Weight worn / Weight before test) × 100%; The table below shows the performance test results of high-strength wear-resistant fasteners;

[0045] Based on the data in the table above, the following conclusions can be drawn: Compared with Example 1, Comparative Example 1 replaced the multifunctional fluorinated polyol with a polyether polyol with a functionality of 2. The tensile strength of the fastener decreased and the wear rate increased because the multifunctional coating system formed a denser cross-linked network after curing, which has higher hardness than the low-functionality coating system. Compared with Example 1, Comparative Example 2 replaced the macromolecular photoinitiator with photoinitiator 2959, and the wear rate of the fasteners increased because the small molecule photoinitiator is prone to phase separation in the macromolecular polymer coating system, which reduces the curing efficiency and affects the performance of the wear-resistant coating. Compared with Example 1, Comparative Example 3 did not functionalize molybdenum disulfide, did not add macromolecular initiators, and replaced UV curing with high-temperature curing. The curing temperature was set to 70°C and the curing time was set to 2 hours. The tensile strength of the fasteners decreased and the wear rate increased because molybdenum disulfide tends to stack in the coating system, resulting in uneven dispersion and affecting the coating performance. Compared with Example 1, the tensile strength of Comparative Example 4 decreased significantly, and the wear rate also increased significantly. In summary, it can be seen that by preparing multifunctional fluorinated polyols, macromolecular photoinitiators, and functionalized molybdenum disulfide, the strength and wear resistance of the fasteners can be comprehensively improved.

[0046] It will be apparent to those skilled in the art that the present invention is not limited to the details of the exemplary embodiments described above, and that the invention can be implemented in other specific forms without departing from the spirit or essential characteristics of the invention. Therefore, the embodiments should be considered in all respects as exemplary and non-limiting, and the scope of the invention is defined by the appended claims rather than the foregoing description. Thus, it is intended that all variations falling within the meaning and scope of equivalents of the claims be included within the present invention.

Claims

1. A process for the production of high strength wear resistant fasteners, characterized by: It comprises the following steps: Take the fastener, in turn, pickling, cleaning, drying, copper plating, forming a copper plating layer, coating wear-resistant paint, ultraviolet curing, forming a wear-resistant coating, obtaining a high-strength wear-resistant fastener; The wear-resistant paint is prepared by the following process: Mix the composite multifunctional polyurethane acrylate, diluent, leveling agent, dispersant, defoaming agent and wetting agent, stir uniformly, heat to 40-50 DEG C, stir for 30-50 min, and obtain the wear-resistant paint.

2. The process of claim 1, wherein: The composite multifunctional polyurethane acrylate is prepared by the following process: In step 1, the mass ratio of isophorone diisocyanate, bisphenol A, dioxane, dibutyltin dilaurate, hydroxyethyl acrylate and multifunctional fluorine-containing polyol solution is 10: (0.02-0.04): (23-26): (0.04-0.06): (14-16): (14-16); In step 2, the mass ratio of double-bond-containing multifunctional polyurethane acrylate, functionalized molybdenum disulfide and macromolecular photoinitiator is 10: (1-3): (0.1-0.5).

3. The process of claim 2, wherein: The mass ratio of dipentaerythritol, dimethyl sulfoxide, KOH and 1,1,1-trifluoro-2,3-epoxypropane is 10: (1.0-1.5): (0.08-0.10): (20-25). The multifunctional fluorine-containing polyol is prepared by the following process: Mix dipentaerythritol and dimethyl sulfoxide, stir uniformly, add KOH, heat and react under nitrogen atmosphere, add 1,1,1-trifluoro-2,3-epoxypropane, and react at constant temperature for 1-2 h, and then vacuum desolventize to obtain the multifunctional fluorine-containing polyol.

4. The process of claim 2, wherein: The preparation process of the macromolecular photoinitiator is as follows: Mix isophorone diisocyanate, dibutyltin dilaurate and polyethylene glycol, stir and react, then add photoinitiator and multifunctional fluorine-containing polyol, heat and stir to react, and reduce pressure to distill to obtain the macromolecular photoinitiator.

5. The process of claim 2, wherein: The functionalized molybdenum disulfide is prepared by the following process: Mix 2,4-dimercapto-5,6-diaminopyrimidine and dimethyl sulfoxide, perform first ultrasonic treatment, then add molybdenum disulfide powder, stir at a speed of 500-600 r / min for 20-24 h, perform second ultrasonic treatment, and centrifugalize and precipitate to obtain the functionalized molybdenum disulfide.

6. The process of claim 2, wherein: In step 1, the mass ratio of isophorone diisocyanate, bisphenol A, dioxane, dibutyltin dilaurate, hydroxyethyl acrylate and multifunctional fluorine-containing polyol solution is 10: (0.02-0.04): (23-26): (0.04-0.06): (14-16): (14-16); In step 2, the mass ratio of double-bond-containing multifunctional polyurethane acrylate, functionalized molybdenum disulfide and macromolecular photoinitiator is 10: (1-3): (0.1-0.5).

7. The process of claim 3, wherein the process further comprises: The mass ratio of dipentaerythritol, dimethyl sulfoxide, KOH and 1,1,1-trifluoro-2,3-epoxypropane is 10: (1.0-1.5): (0.08-0.10): (20-25).

8. The process of claim 4, wherein: The mass ratio of isophorone diisocyanate, dibutyl tin dilaurate, polyethylene glycol, photoinitiator and multifunctional fluorine-containing polyol is 10: (0.10-0.15): (8-12): (4-6): (1.5-2.5).

9. The process of claim 5, wherein: The mass ratio of 2,4-dimercapto-5,6-diaminopyrimidine, dimethyl sulfoxide and molybdenum disulfide powder is 10: (55-65): (0.5-0.7).

10. A high strength wear resistant fastener characterized by: The preparation process according to any one of claims 1-9.

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