A wear-resistant magnetic roller coating and its preparation method

Abstract

The present invention discloses an abrasion-resistant magnetic roller coating and a preparation method thereof, which relates to the technical field of coatings and is made of the following raw materials in parts by weight: 35-45 parts of a film-forming polymer, 4-6 parts of benzidine disulfonic acid, 1-3 parts of phosphorus pentoxide, 0.3-0.6 parts of polyphosphoric acid, 8-10 parts of hyperbranched polyetherimide epoxide, 2-4 parts of dicyandiamide, 3-5 parts of bis-terminal epoxy silicone oil, 1-3 parts of coupling agent, 15-25 parts of inorganic filler, 0.5-0.8 parts of leveling agent; the film-forming polymer is prepared by polycondensation reaction of 2,2-bis[4-(4-aminophenoxy)phenyl]-1,1,1,3,3,3-hexafluoropropane, naphthalene diisocyanate, and bis(3-aminophenyl) 3,5-bis(trifluoromethyl)phenyl phosphine oxide. This abrasion-resistant magnetic roller coating has sufficient adhesion performance, good resistance to damp heat aging, excellent flame retardancy and corrosion resistance, and a long service life.

Description

Technical Field

[0001] The invention relates to the technical field of coatings, and in particular to a wear-resistant magnetic roller coating and a preparation method thereof. Background Art

[0002] Most non-metallic minerals in nature contain harmful impurities such as iron, titanium, and manganese, which affect the whiteness and physical and chemical properties of the product, limit the application field, and reduce the market value. Therefore, the purification of non-metallic minerals requires iron removal, and magnetic separation is the most common and effective method for iron removal of non-metallic minerals. It has the advantages of fast process, no pollution, simple operation, and low production cost. Magnetic separator is an indispensable equipment for magnetic separation, and magnetic roller is one of the important components of magnetic separator. It not only affects the working efficiency of magnetic separator, but also determines the separation index of minerals. It can be seen that the research on magnetic rollers for magnetic separators has become one of the hot topics in the industry.

[0003] The existing magnetic rollers of magnetic separators are seriously worn and corroded, which greatly reduces the service life of the magnetic separators, reduces the operating efficiency, and often causes abnormal shutdowns. In severe cases, the magnetic separators are directly damaged, which leads to a significant increase in production costs. The generation of scrapped equipment and spare parts also leads to a waste of resources. In order to solve the above problems, it is common practice to provide a coating on the surface of the magnetic roller. However, the existing coatings used for the surface of the magnetic rollers of magnetic separators generally have poor wear resistance and are easy to scratch, which seriously affects the magnetic screening of the magnetic separator; other coatings on the market for the surface of the magnetic rollers of magnetic separators also have more or less insufficient adhesion, poor resistance to moisture and heat aging, poor flame retardancy and corrosion resistance, and are prone to bulging and wear-through during use, and have short service life and other technical defects.

[0004] In order to solve the above problems, the Chinese invention patent with the authorization announcement number CN114672241B discloses a coating for the surface of the magnetic roller of a magnetic separator, which is made of the following raw materials in parts by weight: 30-40 parts of terminal methacrylate hyperbranched polythiourethane, 2-4 parts of allyl phenoxyacetate, 3-6 parts of N-(4-cyano-3-trifluoromethylphenyl) methacrylamide, 1-2 parts of 2,4,6-trivinyl cycloboroxane, 5-8 parts of terminal vinyl fluorosilicone oil, 5-10 parts of graphene-coated nano aluminum powder, 2-4 parts of coupling agent, 0.5-0.8 parts of defoamer, 0.3-0.5 parts of leveling agent, 1-2 parts of photoinitiator, 15-20 parts of filler, and 20-30 parts of solvent. The invention also discloses a preparation method of the coating for the surface of the magnetic roller of a magnetic separator. The coating used for the surface of the magnetic roller of the magnetic separator disclosed in the invention has good adhesion, aging resistance and wear resistance, and has a significant protective effect on the magnetic roller of the magnetic separator and a long service life. However, the coating uses volatile organic solvents, and its environmental performance needs to be further improved. In addition, its wear resistance and moisture and heat aging resistance still need to be further improved.

[0005] It can be seen that developing a wear-resistant magnetic roller coating with sufficient adhesion performance, good resistance to damp heat aging, excellent flame retardancy and corrosion resistance, and a long service life, as well as its preparation method, meets the market demand, has broad market value and application prospects, and is of great significance for promoting the development of the magnetic roller coating field. Summary of the Invention

[0006] The main object of the present invention is to provide a wear-resistant magnetic roller coating with sufficient adhesion performance, good resistance to damp heat aging, excellent flame retardancy and corrosion resistance, and a long service life, as well as its preparation method.

[0007] To achieve the above object, the present invention provides a wear-resistant magnetic roller coating, which is made of the following raw materials by weight: 35-45 parts of a film-forming polymer, 4-6 parts of benzidine disulfonic acid, 1-3 parts of phosphorus pentoxide, 0.3-0.6 parts of polyphosphoric acid, 8-10 parts of hyperbranched polyetherimide epoxide, 2-4 parts of dicyandiamide, 3-5 parts of bis-terminal epoxy silicone oil, 1-3 parts of a coupling agent, 15-25 parts of an inorganic filler, 0.5-0.8 parts of a leveling agent; the film-forming polymer is prepared by a polycondensation reaction of 2,2-bis[4-(4-aminophenoxy)phenyl]-1,1,1,3,3,3-hexafluoropropane, naphthalene diisocyanate, and bis(3-aminophenyl) 3,5-bis(trifluoromethyl)phenylphosphine oxide.

[0008] Preferably, the preparation method of the film-forming polymer includes the following steps: adding 2,2-bis[4-(4-aminophenoxy)phenyl]-1,1,1,3,3,3-hexafluoropropane, naphthalene diisocyanate, bis(3-aminophenyl) 3,5-bis(trifluoromethyl)phenylphosphine oxide, and a catalyst to a high-boiling solvent, stirring and reacting at 68-82 °C for 3-5 hours in an inert gas atmosphere, then raising the temperature to 85-93 °C and continuing to stir and react for 7-12 hours, then rotary evaporating to remove the solvent, washing with ether 3-6 times, and then rotary evaporating to remove the residual ether to obtain the film-forming polymer.

[0009] Preferably, the molar ratio of 2,2-bis[4-(4-aminophenoxy)phenyl]-1,1,1,3,3,3-hexafluoropropane, naphthalene diisocyanate, bis(3-aminophenyl) 3,5-bis(trifluoromethyl)phenylphosphine oxide, the catalyst, and the high-boiling solvent is 0.8:1:0.2:(0.8-1.2):(10-15).

[0010] Preferably, the catalyst is at least one of dibutyltin dilaurate and stannous octoate; the high-boiling solvent is at least one of dimethyl sulfoxide, N,N-dimethylformamide, and N,N-dimethylacetamide; the inert gas is any one of nitrogen, helium, neon, and argon.

[0011] Preferably, there are no special requirements for the source of the hyperbranched polyetherimide epoxide. In one embodiment of the present invention, the hyperbranched polyetherimide epoxide is prepared by the method of Example 35 of the Chinese invention patent with the authorization announcement number CN110951076B.

[0012] Preferably, the bis-terminal epoxy silicone oil is IOTA 105 epoxy silicone oil with the specification of 105-2, purchased from Anhui Aiyota Silicone Oil Co., Ltd.

[0013] Preferably, the coupling agent is at least one of silane coupling agent KH550, silane coupling agent KH560, and silane coupling agent KH570.

[0014] Preferably, the inorganic filler is a mixture formed by mixing molybdenum disulfide, double fly powder, and graphene in a mass ratio of 1:(1-3):2; the particle size of the inorganic filler is 1300-1800 mesh; the graphene is single-layer graphene with an average diameter of 1-15 microns, provided by Chengdu Institute of Organic Chemistry.

[0015] Preferably, the leveling agent is at least one of German BYK leveling agent BYK-333 and silicone leveling agent HY-5030.

[0016] Another object of the present invention is to provide a method for preparing the wear-resistant magnetic roller coating, which includes the following steps: adding each raw material by weight to a high-speed mixer and mixing for 6-9 min, then feeding it into an extruder for extrusion. The extruded material is crushed by a powder coating crusher into powder particles with an average particle size of 40-50 microns. The powder passes through a 120-180 mesh sieve, and high-voltage electrostatic spraying is used with an average film thickness of 60-80 microns, and then baked at 180-190 °C for 25-35 min to obtain the wear-resistant magnetic roller coating.

[0017] Preferably, the voltage of the high-voltage electrostatic spraying is 65-95 KV.

[0018] Due to the application of the above technical solutions, the present invention has the following beneficial effects:

[0019] (1) The preparation method of the wear-resistant magnetic roller coating disclosed by the present invention has a preparation process with convenient operation and control, does not require special equipment, nor does it need to transform the original production line. It has low capital investment, low energy consumption, high preparation efficiency and high finished product qualification rate, is suitable for continuous large-scale production, and has high promotion and application value.

[0020] (2) The wear-resistant magnetic roller coating disclosed by the present invention is made from the following raw materials in parts by weight: 35-45 parts of film-forming polymer, 4-6 parts of benzidine disulfonic acid, 1-3 parts of phosphorus pentoxide, 0.3-0.6 parts of polyphosphoric acid, 8-10 parts of hyperbranched polyetherimide epoxide, 2-4 parts of dicyandiamide, 3-5 parts of bis-terminal epoxy silicone oil, 1-3 parts of coupling agent, 15-25 parts of inorganic filler, and 0.5-0.8 parts of leveling agent; the film-forming polymer is made by polycondensation reaction of 2,2-bis[4-(4-aminophenoxy)phenyl]-1,1,1,3,3,3-hexafluoropropane, naphthalene diisocyanate, and bis(3-aminophenyl) 3,5-bis(trifluoromethyl)phenylphosphine oxide. Through the mutual cooperation and joint action of each raw material, the prepared coating has sufficient adhesion performance, good resistance to damp heat aging performance, excellent flame retardancy and corrosion resistance, and a long service life. Through the reasonable selection of each raw material and its dosage, urea groups, fluorinated phenyl ethers, naphthyl groups, fluorinated phenylphosphine oxides, biphenyls, hyperbranched polyetherimides, and silicone oil structures are simultaneously introduced into the molecular structure of the coating. Under the multiple effects of electronic effects, steric effects, and conjugation effects, etc., the prepared coating has better resistance to damp heat aging performance, more excellent flame retardancy and corrosion resistance, and a longer service life.

[0021] (3) For the wear-resistant magnetic roller coating disclosed by the present invention, the sulfonic acid groups on benzidine disulfonic acid can undergo a chemical reaction with the benzene rings on the film-forming polymer under the catalytic action of phosphorus pentoxide and polyphosphoric acid. At the same time, the raw materials containing epoxy groups can react chemically with the raw materials containing amino groups and dicyandiamide to cure, forming a multiple interpenetrating network structure in the coating. The simultaneous presence of these structures can effectively improve the resistance to damp heat aging performance, flame retardancy, and corrosion resistance of the coating; the hydroxyl groups and other groups introduced by the epoxy ring-opening reaction can also improve the adhesion of the coating.

[0022] (4) For the wear-resistant magnetic roller coating disclosed by the present invention, the inorganic filler is a mixture formed by mixing molybdenum disulfide, double fly powder, and graphene in a mass ratio of 1:(1-3):2; through the reasonable compatibility of these fillers and the cooperation with other raw materials, it can effectively reduce the eddy current generated when the magnetic roller rotates in the magnetic field, so as to reduce the driving power and heating degree of the magnetic roller, reduce energy consumption, and at the same time prevent the huge wear of the magnetic roller caused by the erosion of ore particles, reduce the service life, and avoid the sharp drop of the magnetic field gradient, affecting the sorting index of minerals. Detailed implementation mode

[0023] The following description is used to disclose the present invention so that those skilled in the art can implement the present invention. The preferred embodiments in the following description are only examples, and those skilled in the art can think of other obvious variations. Example 1

[0024] A wear-resistant magnetic roller coating is made from the following raw materials by weight: 35 parts of film-forming polymer, 4 parts of benzidine disulfonic acid, 1 part of phosphorus pentoxide, 0.3 part of polyphosphoric acid, 8 parts of hyperbranched polyetherimide epoxide, 2 parts of dicyandiamide, 3 parts of bis-terminal epoxy silicone oil, 1 part of coupling agent, 15 parts of inorganic filler, 0.5 part of leveling agent; the film-forming polymer is made by polycondensation reaction of 2,2-bis[4-(4-aminophenoxy)phenyl]-1,1,1,3,3,3-hexafluoropropane, naphthalene diisocyanate, and bis(3-aminophenyl) 3,5-bis(trifluoromethyl)phenylphosphine oxide.

[0025] The preparation method of the film-forming polymer includes the following steps: adding 2,2-bis[4-(4-aminophenoxy)phenyl]-1,1,1,3,3,3-hexafluoropropane, naphthalene diisocyanate, bis(3-aminophenyl) 3,5-bis(trifluoromethyl)phenylphosphine oxide, and catalyst into a high-boiling solvent, stirring and reacting at 68 °C for 3 hours under an inert gas atmosphere, then heating to 85 °C and continuing to stir and react for 7 hours, then rotary evaporating to remove the solvent, washing with ether 3 - 6 times, and then rotary evaporating to remove the residual ether to obtain the film-forming polymer; the molar ratio of 2,2-bis[4-(4-aminophenoxy)phenyl]-1,1,1,3,3,3-hexafluoropropane, naphthalene diisocyanate, bis(3-aminophenyl) 3,5-bis(trifluoromethyl)phenylphosphine oxide, catalyst, and high-boiling solvent is 0.8:1:0.2:0.8:1; the catalyst is dibutyltin dilaurate; the high-boiling solvent is dimethyl sulfoxide; the inert gas is nitrogen; through GPC test, the M n of this copolymer is 14610 g / mol, and M W / M n is 1.337; through elemental quantitative analysis and weight change calculation, it is confirmed that the molar ratio of the structural units introduced by 2,2-bis[4-(4-aminophenoxy)phenyl]-1,1,1,3,3,3-hexafluoropropane, naphthalene diisocyanate, and bis(3-aminophenyl) 3,5-bis(trifluoromethyl)phenylphosphine oxide in the film-forming polymer is about 0.8:1:0.2, which is the same as the theoretical value.

[0026] The hyperbranched polyetherimide epoxide is made according to the method of Example 35 of the Chinese invention patent with the authorization announcement number CN110951076B; the bis-terminal epoxy silicone oil is IOTA 105 epoxy silicone oil with the specification of 105-2, purchased from Anhui Aiyota Silicone Oil Co., Ltd.

[0027] The coupling agent is silane coupling agent KH550; the inorganic filler is a mixture formed by mixing molybdenum disulfide, whiting, and graphene in a mass ratio of 1:1:2; the particle size of the inorganic filler is 1300 mesh; the graphene is monolayer graphene with an average diameter of 1 micron, provided by Chengdu Institute of Organic Chemistry; the leveling agent is BYK leveling agent BYK-333 from BYK of Germany.

[0028] A preparation method of the wear-resistant magnetic roller coating comprises the following steps: adding each raw material by weight parts into a high-speed mixer and mixing for 6 min, then feeding into an extruder for extrusion. The extruded material is crushed into powder particles with an average particle size of 40 microns by a powder coating grinder, and the powder passes through a 120-mesh sieve. Then, high-voltage electrostatic spraying is used with an average coating thickness of 60 microns, and then baking is carried out at 180 °C for 25 min to obtain the wear-resistant magnetic roller coating; the voltage of the high-voltage electrostatic spraying is 65 KV. Example 2

[0029] A wear-resistant magnetic roller coating is made from the following raw materials by weight parts: 37 parts of film-forming polymer, 4.5 parts of benzidine disulfonic acid, 1.5 parts of phosphorus pentoxide, 0.4 part of polyphosphoric acid, 8.5 parts of hyperbranched polyetherimide epoxide, 2.5 parts of dicyandiamide, 3.5 parts of bis-terminal epoxy silicone oil, 1.5 parts of coupling agent, 17 parts of inorganic filler, and 0.6 part of leveling agent; the film-forming polymer is made by polycondensation reaction of 2,2-bis[4-(4-aminophenoxy)phenyl]-1,1,1,3,3,3-hexafluoropropane, naphthalene diisocyanate, and bis(3-aminophenyl) 3,5-bis(trifluoromethyl)phenyl phosphine oxide.

[0030] The preparation method of the film-forming polymer comprises the following steps: adding 2,2-bis[4-(4-aminophenoxy)phenyl]-1,1,1,3,3,3-hexafluoropropane, naphthalene diisocyanate, bis(3-aminophenyl) 3,5-bis(trifluoromethyl)phenyl phosphine oxide, and a catalyst into a high-boiling solvent, stirring and reacting at 72 °C for 3.5 hours under an inert gas atmosphere, then raising the temperature to 87 °C and continuing to stir and react for 9 hours. Then, the solvent is removed by rotary evaporation, washed 4 times with ether, and the residual ether is removed by rotary evaporation to obtain the film-forming polymer; the molar ratio of 2,2-bis[4-(4-aminophenoxy)phenyl]-1,1,1,3,3,3-hexafluoropropane, naphthalene diisocyanate, bis(3-aminophenyl) 3,5-bis(trifluoromethyl)phenyl phosphine oxide, the catalyst, and the high-boiling solvent is 0.8:1:0.2:0.9:11; the catalyst is stannous octoate; the high-boiling solvent is N,N-dimethylformamide; the inert gas is helium.

[0031] The hyperbranched polyetherimide epoxide is prepared by the method of Example 35 of the Chinese invention patent with the authorized announcement number of CN110951076B; the bis-terminal epoxy silicone oil is IOTA 105 epoxy silicone oil with the specification of 105-2, purchased from Anhui Aiyota Silicone Oil Co., Ltd.; the coupling agent is silane coupling agent KH560; the inorganic filler is a mixture formed by mixing molybdenum disulfide, double fly powder, and graphene in a mass ratio of 1:1.5:2; the particle size of the inorganic filler is 1400 mesh; the graphene is monolayer graphene with an average diameter of 5 microns, provided by Chengdu Institute of Organic Chemistry; the leveling agent is at least one of the silicone leveling agent HY-5030.

[0032] A preparation method of the wear-resistant magnetic roller coating includes the following steps: adding each raw material by weight into a high-speed mixer and mixing for 7 min, then feeding it into an extruder for extrusion. The extruded material is pulverized into powder particles with an average particle size of 43 microns by a powder coating pulverizer, and the powder passes through a 140-mesh sieve. High-voltage electrostatic spraying is used with an average coating thickness of 60 microns, and then it is baked at 183 °C for 27 min to obtain the wear-resistant magnetic roller coating; the voltage of the high-voltage electrostatic spraying is 75 KV. Example 3

[0033] A wear-resistant magnetic roller coating is made from the following raw materials by weight: 35-45 parts of film-forming polymer, 5 parts of benzidine disulfonic acid, 2 parts of phosphorus pentoxide, 0.45 part of polyphosphoric acid, 9 parts of hyperbranched polyetherimide epoxide, 3 parts of dicyandiamide, 4 parts of bis-terminal epoxy silicone oil, 2 parts of coupling agent, 20 parts of inorganic filler, and 0.65 part of leveling agent; the film-forming polymer is prepared by a polycondensation reaction of 2,2-bis[4-(4-aminophenoxy)phenyl]-1,1,1,3,3,3-hexafluoropropane, naphthalene diisocyanate, and bis(3-aminophenyl) 3,5-bis(trifluoromethyl)phenylphosphine oxide.

[0034] The preparation method of the film-forming polymer comprises the following steps: adding 2,2-bis[4-(4-aminophenoxy)phenyl]-1,1,1,3,3,3-hexafluoropropane, naphthalene diisocyanate, bis(3-aminophenyl)3,5-bis(trifluoromethyl)phenylphosphine oxide, and a catalyst into a high-boiling solvent, stirring and reacting at 76 °C for 4 hours under an inert gas atmosphere, then raising the temperature to 89 °C and continuing to stir and react for 10 hours, then rotary evaporating to remove the solvent, washing with ether 5 times, and then rotary evaporating to remove the residual ether to obtain the film-forming polymer; the molar ratio of 2,2-bis[4-(4-aminophenoxy)phenyl]-1,1,1,3,3,3-hexafluoropropane, naphthalene diisocyanate, bis(3-aminophenyl)3,5-bis(trifluoromethyl)phenylphosphine oxide, the catalyst, and the high-boiling solvent is 0.8:1:0.2:1:13; the catalyst is dibutyltin dilaurate; the high-boiling solvent is N,N-dimethylacetamide; the inert gas is neon.

[0035] The hyperbranched polyetherimide epoxide is prepared by the method of Example 35 of the Chinese invention patent with the authorization announcement number CN110951076B; the bis-terminal epoxy silicone oil is IOTA 105 epoxy silicone oil with the specification of 105-2, purchased from Anhui Aiyota Silicone Oil Co., Ltd.; the coupling agent is silane coupling agent KH570; the inorganic filler is a mixture formed by mixing molybdenum disulfide, double fly powder, and graphene according to the mass ratio of 1:2.5:2; the particle size of the inorganic filler is 1700 mesh; the graphene is monolayer graphene with an average diameter of 10 microns, provided by Chengdu Institute of Organic Chemistry; the leveling agent is BYK leveling agent BYK-333 from BYK of Germany.

[0036] A preparation method of the wear-resistant magnetic roller coating comprises the following steps: adding each raw material by weight parts into a high-speed mixer and mixing for 7.5 min, then feeding it into an extruder for extrusion, crushing the extruded material into powder particles with an average particle size of 45 microns by a powder coating crusher, sieving the powder through a 150-mesh sieve, using high-voltage electrostatic spraying with an average film thickness of 60 microns, and then baking at 185 °C for 30 min to obtain the wear-resistant magnetic roller coating; the voltage of the high-voltage electrostatic spraying is 80 KV. Example 4

[0037] A wear-resistant magnetic roller coating is made of the following raw materials by weight: 43 parts of film-forming polymer, 5.5 parts of benzidine disulfonic acid, 2.5 parts of phosphorus pentoxide, 0.55 part of polyphosphoric acid, 9.5 parts of hyperbranched polyetherimide epoxide, 3.5 parts of dicyandiamide, 4.5 parts of bis-terminal epoxy silicone oil, 2.5 parts of coupling agent, 23 parts of inorganic filler, and 0.75 part of leveling agent; the film-forming polymer is made by polycondensation reaction of 2,2-bis[4-(4-aminophenoxy)phenyl]-1,1,1,3,3,3-hexafluoropropane, naphthalene diisocyanate, and bis(3-aminophenyl) 3,5-bis(trifluoromethyl)phenyl phosphine oxide.

[0038] The preparation method of the film-forming polymer includes the following steps: adding 2,2-bis[4-(4-aminophenoxy)phenyl]-1,1,1,3,3,3-hexafluoropropane, naphthalene diisocyanate, bis(3-aminophenyl) 3,5-bis(trifluoromethyl)phenyl phosphine oxide, and catalyst into a high-boiling solvent, stirring and reacting at 80 °C for 4.5 hours in an inert gas atmosphere, then heating to 92 °C and continuing to stir and react for 11 hours, then rotary evaporating to remove the solvent, washing with ether 3-6 times, and then rotary evaporating to remove the residual ether to obtain the film-forming polymer; the molar ratio of 2,2-bis[4-(4-aminophenoxy)phenyl]-1,1,1,3,3,3-hexafluoropropane, naphthalene diisocyanate, bis(3-aminophenyl) 3,5-bis(trifluoromethyl)phenyl phosphine oxide, catalyst, and high-boiling solvent is 0.8:1:0.2:1.1:14; the catalyst is a mixture formed by mixing dibutyltin dilaurate and stannous octoate in a mass ratio of 3:5; the high-boiling solvent is a mixture formed by mixing dimethyl sulfoxide, N,N-dimethylformamide, and N,N-dimethylacetamide in a mass ratio of 1:2:3; the inert gas is argon.

[0039] The hyperbranched polyetherimide epoxide is made according to the method of Example 35 of the Chinese invention patent with the authorization announcement number CN110951076B; the bis-terminal epoxy silicone oil is IOTA 105 epoxy silicone oil with a specification of 105-2, purchased from Anhui Aiyota Silicone Oil Co., Ltd.; the coupling agent is a mixture formed by mixing silane coupling agent KH550, silane coupling agent KH560, and silane coupling agent KH570 in a mass ratio of 1:2:3; the inorganic filler is a mixture formed by mixing molybdenum disulfide, double fly powder, and graphene in a mass ratio of 1:2.5:2; the particle size of the inorganic filler is 1700 mesh; the graphene is monolayer graphene with an average diameter of 14 microns, provided by Chengdu Institute of Organic Chemistry; the leveling agent is a mixture formed by mixing German BYK leveling agent BYK-333 and silicone leveling agent HY-5030 in a mass ratio of 3:5.

[0040] A preparation method of the wear-resistant magnetic roller coating includes the following steps: Add each raw material by weight parts into a high-speed mixer and mix for 8.5 minutes, then send it into an extruder for extrusion. The extruded material is crushed by a powder coating crusher into powder particles with an average particle size of 48 microns. The powder passes through a 170-mesh sieve, and high-voltage electrostatic spraying is used with an average film thickness of 60 microns. Then it is baked at 188 °C for 33 minutes to obtain the wear-resistant magnetic roller coating; the voltage of the high-voltage electrostatic spraying is 90 KV. Example 5

[0041] A wear-resistant magnetic roller coating is made of the following raw materials by weight parts: 45 parts of film-forming polymer, 6 parts of benzidine disulfonic acid, 3 parts of phosphorus pentoxide, 0.6 part of polyphosphoric acid, 10 parts of hyperbranched polyetherimide epoxide, 4 parts of dicyandiamide, 5 parts of bis-terminal epoxy silicone oil, 3 parts of coupling agent, 25 parts of inorganic filler, 0.8 part of leveling agent; the film-forming polymer is made by a polycondensation reaction of 2,2-bis[4-(4-aminophenoxy)phenyl]-1,1,1,3,3,3-hexafluoropropane, naphthalene diisocyanate, and bis(3-aminophenyl) 3,5-bis(trifluoromethyl)phenylphosphine oxide.

[0042] The preparation method of the film-forming polymer includes the following steps: Add 2,2-bis[4-(4-aminophenoxy)phenyl]-1,1,1,3,3,3-hexafluoropropane, naphthalene diisocyanate, bis(3-aminophenyl) 3,5-bis(trifluoromethyl)phenylphosphine oxide, and catalyst into a high-boiling solvent. Under an inert gas atmosphere, stir and react at 82 °C for 5 hours, then raise the temperature to 93 °C and continue to stir and react for 12 hours. Then rotary evaporate to remove the solvent, wash with ether 6 times, and then rotary evaporate to remove the residual ether to obtain the film-forming polymer; the molar ratio of 2,2-bis[4-(4-aminophenoxy)phenyl]-1,1,1,3,3,3-hexafluoropropane, naphthalene diisocyanate, bis(3-aminophenyl) 3,5-bis(trifluoromethyl)phenylphosphine oxide, catalyst, and high-boiling solvent is 0.8:1:0.2:1.2:15; the catalyst is dibutyltin dilaurate; the high-boiling solvent is N,N-dimethylacetamide; the inert gas is argon.

[0043] The hyperbranched polyetherimide epoxide is made by the method of Example 35 of the Chinese invention patent with the authorization announcement number CN110951076B; the bis-terminal epoxy silicone oil is IOTA 105 epoxy silicone oil with the specification of 105-2, purchased from Anhui Aiyota Silicone Oil Co., Ltd.; the coupling agent is silane coupling agent KH550; the inorganic filler is a mixture formed by mixing molybdenum disulfide, double fly powder, and graphene in a mass ratio of 1:3:2; the particle size of the inorganic filler is 1800 mesh; the graphene is single-layer graphene with an average diameter of 15 microns, provided by Chengdu Institute of Organic Chemistry; the leveling agent is BYK leveling agent BYK-333 from BYK of Germany.

[0044] A preparation method of the wear-resistant magnetic roller coating includes the following steps: Add each raw material by weight parts into a high-speed mixer and mix for 9 min, then send it into an extruder for extrusion. The extruded material is crushed into powder particles with an average particle size of 50 microns by a powder coating grinder. The powder passes through a 180-mesh sieve, and high-voltage electrostatic spraying is used with an average coating thickness of 60 microns. Then it is baked at 190 °C for 35 min to obtain the wear-resistant magnetic roller coating; the voltage of the high-voltage electrostatic spraying is 95 KV.

[0045] Comparative Example 1

[0046] The present invention provides a wear-resistant magnetic roller coating and its preparation method, which is similar to Example 1, except that hyperbranched polyetherimide epoxide is not added, and 2,2-bis[4-(4-aminophenoxy)phenyl]-1,1,1,3,3,3-hexafluoropropane is used to replace bis(3-aminophenyl) 3,5-bis(trifluoromethyl)phenylphosphine oxide.

[0047] Comparative Example 2

[0048] The present invention provides a wear-resistant magnetic roller coating and its preparation method, which is similar to Example 1, except that bis-terminal epoxy silicone oil is not added, and bis(3-aminophenyl) 3,5-bis(trifluoromethyl)phenylphosphine oxide is used to replace 2,2-bis[4-(4-aminophenoxy)phenyl]-1,1,1,3,3,3-hexafluoropropane.

[0049] Perform relevant performance tests on the wear-resistant magnetic roller coating samples prepared in the above Examples 1-5 and Comparative Examples 1-2. The test results are shown in Table 1, and the test methods are as follows:

[0050] (1) Flame retardancy: Test according to UL-94.

[0051] (2) Abrasion resistance: Test according to the method shown in ASTM D4060, with a grinding wheel CS-17, a load of 1000 g, and 800 r.

[0052] (3) Adhesion grade: Test with reference to GB / T 9286-1998.

[0053] (4) Corrosion resistance: Refer to GB / T 1771-2007 for the salt spray test. The test time is 1200 h. If the coating has no blistering, softening, no micropores, and no change in viscosity, the corrosion resistance passes, otherwise it fails.

[0054] (5) Damp heat resistance: Place the products of each example in an environment with a temperature of 90 °C and a relative humidity of 90% for 504 hours. After cooling to room temperature, observe the change of the coating. If the coating has no blistering, softening, no micropores, and no change in viscosity, the damp heat resistance passes, otherwise it fails.

[0055] Table 1

[0056] Project Flame retardancy (grade) Abrasion resistance (weight loss, mg) Adhesion grade (grade) Salt spray resistance test for 1200 h Damp heat resistance Example 1 V-0 8 1 Passed Passed Example 2 V-0 5 1 Passed Passed Example 3 V-0 4 1 Passed Passed Example 4 V-0 2 1 Passed Passed Example 5 V-0 1 1 Passed Passed Comparative example 1 V-2 27 2 Failed Failed Comparative example 2 V-1 34 2 Failed Failed

[0057] As can be seen from Table 1, the wear-resistant magnetic roller coating disclosed in the embodiments of the present invention has more excellent flame retardancy, wear resistance, adhesion, corrosion resistance and damp heat resistance compared with the products of the comparative examples; the combined use of hyperbranched polyetherimide epoxide, 2,2-bis[4-(4-aminophenoxy)phenyl]-1,1,1,3,3,3-hexafluoropropane, bis(3-aminophenyl) 3,5-bis(trifluoromethyl)phenylphosphine oxide and bis-terminal epoxy silicone oil is beneficial to improving the above performances.

[0058] The foregoing shows and describes the basic principles, main features and advantages of the present invention. Those skilled in the art should understand that the present invention is not limited by the above embodiments, and what is described in the above embodiments and the specification is only the principle of the present invention. Without departing from the spirit and scope of the present invention, the present invention will have various changes and improvements, and these changes and improvements all fall within the scope of the present invention claimed. The scope of protection required by the present invention is defined by the appended claims and their equivalents.

Claims

1. A wear-resistant magnetic roller coating, characterized in that: The invention is prepared from the following raw materials in parts by weight: 35-45 parts of film-forming polymer, 4-6 parts of benzidine disulfonic acid, 1-3 parts of phosphorus pentoxide, 0.3-0.6 parts of polyphosphoric acid, 8-10 parts of hyperbranched polyetherimide epoxy compound, 2-4 parts of dicyandiamide, 3-5 parts of double-terminal epoxy silicone oil, 1-3 parts of coupling agent, 15-25 parts of inorganic filler and 0.5-0.8 parts of leveling agent; the film-forming polymer is prepared from 2,2-bis[4-(4-aminophenoxy)phenyl]-1,1,1,3,3,3-hexafluoropropane, naphthalene diisocyanate and bis(3-aminophenyl) 3,5-bis(trifluoromethyl)phenylphosphine oxide through polycondensation reaction; The hyperbranched polyetherimide epoxy compound is prepared by the following preparation method: Step S1, 19.00 g of triphenolmethane, 100 mL of toluene, and 160 mL of N-methylpyrrolidone were added to a 500 mL four-necked reaction flask equipped with a mechanical stirrer, a thermometer, a water separator, a condenser, and a nitrogen inlet; after nitrogen was passed through the system to remove the air in the system, 11.20 g of catalyst potassium carbonate was added under stirring; the temperature was then raised to 180° C. until the toluene / water azeotrope was completely separated; the system temperature was then lowered to room temperature, and 26.47 g of 4,4′-bis(4-chlorophthalimide)diphenyl ether monomer, raising the temperature to 180°C and reacting for 8 hours; after cooling to room temperature, slowly pouring the reaction solution into a mixed solution of 1L water and concentrated hydrochloric acid for precipitation, and filtering to obtain a crude product; the crude product is dissolved in 150mL tetrahydrofuran, and then precipitated with a mixed solution of 750mL ethanol and water; the product is collected and dried in a vacuum oven at 90°C for 24 hours to obtain a terminal phenolic hydroxyl fully aromatic hyperbranched polyetherimide; the volume ratio of concentrated hydrochloric acid to water in the mixed solution of water and concentrated hydrochloric acid is 1:20; the volume ratio of ethanol to water in the mixed solution of ethanol and water is 1:1; Step S2, adding 10g of terminal phenolic hydroxyl fully aromatic hyperbranched polyetherimide and 75.96g of epichlorohydrin to a reaction bottle, heating to 110°C and stirring for 2 hours; then adding 1.30g of catalyst tetrabutylammonium bromide to the reaction bottle, stirring and reacting at 110°C for 3 hours; after the system temperature dropped to 45°C, 30% sodium hydroxide aqueous solution was added dropwise; after the addition was completed, the system continued to react at 45°C for 4 hours, and after the reaction was completed, the temperature was lowered to room temperature, and the filtrate was filtered and collected; under vigorous stirring The filtrate is slowly poured into 200 mL of ethanol to precipitate a crude product; the crude product is dissolved in 15 mL of tetrahydrofuran and slowly poured into a mixed solution of 200 mL of ethanol and water under stirring; the dissolution and precipitation are repeated twice, the product is collected and dried in a vacuum oven at 50° C. for 5 hours, and then freeze-dried using a freeze dryer; the 30% sodium hydroxide aqueous solution is composed of 1.00 g of sodium hydroxide and 2.40 g of water; the volume ratio of ethanol to water in the mixed solution of ethanol and water is 3:

1.

2. The wear-resistant magnetic roller coating according to claim 1, characterized in that: The preparation method of the film-forming polymer comprises the following steps: adding 2,2-bis[4-(4-aminophenoxy)phenyl]-1,1,1,3,3,3-hexafluoropropane, naphthalene diisocyanate, bis(3-aminophenyl)3,5-bis(trifluoromethyl)phenylphosphine oxide and a catalyst into a high boiling point solvent, stirring and reacting for 3-5 hours at 68-82° C. in an inert gas atmosphere, then heating to 85-93° C. and continuing stirring and reacting for 7-12 hours, then rotary evaporating to remove the solvent, washing with ether for 3-6 times, and then rotary evaporating to remove the residual ether to obtain a film-forming polymer.

3. The wear-resistant magnetic roller coating according to claim 2, characterized in that: The molar ratio of the 2,2-bis[4-(4-aminophenoxy)phenyl]-1,1,1,3,3,3-hexafluoropropane, naphthalene diisocyanate, bis(3-aminophenyl)3,5-bis(trifluoromethyl)phenylphosphine oxide, catalyst and high boiling point solvent is 0.8:1:0.2:(0.8-1.2):(10-15).

4. The wear-resistant magnetic roller coating according to claim 2, characterized in that: The catalyst is at least one of dibutyltin dilaurate and stannous octoate; the high boiling point solvent is at least one of dimethyl sulfoxide, N,N-dimethylformamide and N,N-dimethylacetamide; and the inert gas is any one of nitrogen, helium, neon and argon.

5. The wear-resistant magnetic roller coating according to claim 1, characterized in that: The coupling agent is at least one of silane coupling agent KH550, silane coupling agent KH560 and silane coupling agent KH570.

6. The wear-resistant magnetic roller coating according to claim 1, characterized in that: The inorganic filler is a mixture of molybdenum disulfide, double fly ash and graphene in a mass ratio of 1:(1-3):2; the particle size of the inorganic filler is 1300-1800 mesh; and the graphene is single-layer graphene with an average diameter of 1-15 microns.

7. The wear-resistant magnetic roller coating according to claim 1, characterized in that: The leveling agent is at least one of German BYK leveling agent BYK-333 and silicone leveling agent HY-5030.

8. A method for preparing the wear-resistant magnetic roller coating according to any one of claims 1 to 7, characterized in that: The method comprises the following steps: adding each raw material by weight into a high-speed mixer and mixing for 6-9 minutes, and then feeding into an extruder for extrusion; crushing the extruded material into powder particles with an average particle size of 40-50 microns by a powder coating crusher; passing the powder through a 120-180 mesh sieve; using high-voltage electrostatic spraying to obtain an average coating thickness of 60-80 microns; and then baking at 180-190°C for 25-35 minutes to obtain a wear-resistant magnetic roller coating.

9. The method for preparing the wear-resistant magnetic roller coating according to claim 8, characterized in that: The voltage of the high-voltage electrostatic spraying is 65-95KV.