High-wear-resistance resin abrasive disc and preparation method thereof

Abstract

The invention relates to a high-wear-resistance resin abrasive disc and a preparation method thereof, and belongs to the technical field of high polymer materials. The high-wear-resistance resin abrasive disc comprises the following components in parts by weight: 30-40 parts of microcrystalline diamond, 20-30 parts of white corundum, 6-10 parts of fused alumina zirconia, 5-8 parts of a modified toughening agent, 20-25 parts of modified phenolic resin and 3-5 parts of magnesium oxide, modified boron nitride in the modified flexibilizer promotes resin curing, amino and resin cross-linking, interface bonding force is enhanced, toughening is achieved, carboxyl-terminated nitrile rubber improves the resin toughness, and dopamine increases the distance between boron nitride, weakens Van der Waals force and prevents boron nitride agglomeration; the boron element is introduced into the modified phenolic resin, a three-dimensional network structure is formed during curing, good heat resistance is given, and vinyl trimethoxy silane is high in Si-O bond energy and large in molecular flexibility, so that the heat stability is enhanced; the high-wear-resistance resin abrasive disc prepared by the preparation method disclosed by the invention not only has a good toughening effect, but also has excellent high-temperature-resistant and flame-retardant effects.

Description

Technical Field

[0001] The invention belongs to the technical field of polymer materials, and in particular relates to a high wear-resistant resin grinding disc and a preparation method thereof. Background Art

[0002] Abrasive discs are widely used in stone processing, mainly for trimming, grinding, cutting and polishing the surface of sawn stone to give it a certain glossiness. In the field of abrasive tool manufacturing, the technology of using thermoplastic phenolic resin to make abrasive tools has matured.

[0003] However, the thermoplastic phenolic resin currently used to prepare resin abrasive tools has problems such as low molecular weight dispersion coefficient, poor high-temperature fluidity, insufficient toughness, and high brittleness, which seriously affect the quality of the resin abrasive tools, resulting in poor grinding performance, rapid abrasive tool performance decay, and short service life, which limits the use efficiency; in addition, although phenolic resin grinding discs have certain flame retardancy, with the increase in actual application needs, their own flame retardancy can no longer meet the needs. Therefore, the research and development of high-wear-resistant resin grinding discs with excellent performance has important practical significance and application value. Summary of the invention

[0004] In order to solve the above technical problems, the present invention provides a highly wear-resistant resin abrasive disc and a preparation method thereof.

[0005] The purpose of the present invention can be achieved through the following technical solutions: A high wear-resistant resin grinding disc comprises the following raw materials in parts by weight: 30-40 parts of microcrystalline diamond, 20-30 parts of white corundum, 6-10 parts of zirconium corundum, 5-8 parts of modified toughening agent, 20-25 parts of modified phenolic resin and 3-5 parts of magnesium oxide.

[0006] The modified toughening agent is prepared by the following method: Step A1: isopropanol and deionized water are mixed evenly, hexagonal boron nitride powder is added, ultrasonic reaction is performed for 8 hours, centrifuged at a speed of 5000 r / min for 30 minutes, and then the supernatant after centrifugation is centrifuged at a speed of 12000 r / min for 30 minutes, vacuum dried at 60°C for 20 hours, and ground to obtain modified boron nitride; Further, the dosage ratio of isopropanol, deionized water, and hexagonal boron nitride powder is 60-100 mL: 90-150 mL: 2-3 g; Firstly, the hexagonal boron nitride powder is peeled off into nano boron nitride by ultrasonic peeling method to obtain modified boron nitride; Step A2: Modified boron nitride and tris(hydroxymethyl)aminomethane were mixed, ultrasonicated at a power of 200 W for 3-10 min, dopamine hydrochloride was added, stirred for 24 h, washed, filtered, and dried at 60° C. for 20 h to obtain a compound; Further, the mass ratio of modified boron nitride, tris(hydroxymethyl)aminomethane, and dopamine hydrochloride is 1 g: 1.34-2.02 g: 0.3 g; Secondly, dopamine is oxidized to form polydopamine and the surface of the modified boron nitride is modified to obtain a hydroxyl-containing compound; Step A3: Mix the carboxyl-terminated nitrile rubber, the compound and dioctyl phthalate and stir them evenly, then add hydrofluoric acid and mix them, react at 120° C. for 6 hours, cool and distill to obtain a modified toughening agent; Further, the amount ratio of the carboxyl-terminated nitrile rubber, the compound, dioctyl phthalate, and hydrofluoric acid is 0.02 mol: 0.01 mol: 0.01-0.03 g: 0.06 g; Finally, the hydroxyl group of the compound reacts with the carboxyl group of the carboxyl-terminated nitrile rubber to generate a modified toughening agent; The modified phenolic resin is prepared by the following method: Step B1: Phenol, ammonia solution and formaldehyde were mixed evenly, reacted in an oil bath at 70°C for 2 hours with stirring, and vacuum distilled at 70°C and a vacuum degree of -0.08MPa, and then boric acid was added and mixed, and the reaction was continued at 100°C for 80 minutes, and vacuum distilled to obtain an intermediate; Further, the dosage ratio of phenol, ammonia solution, formaldehyde, and boric acid is 4.7-9.4 g: 0.6-1.2 mL: 2.3-4.6 g: 0.93 g, and the concentration of ammonia solution is 25%; First, phenol and formaldehyde are reacted to generate phenolic resin, and then the hydroxyl group of boric acid is reacted with the hydroxyl group of the phenolic resin to generate an intermediate; Step B2: Vinyltrimethoxysilane and ethanol are mixed, stirred at 80°C for 10 hours, cooled to room temperature, filtered, washed, added with the intermediate, reacted for 1 hour, then 9,10-dihydro-9-oxa-10-phosphaphenanthrene-10-oxide is added, stirred for 12 hours, cured continuously at each temperature of 100°C, 120°C, 150°C and 180°C for 2 hours, dried at 60°C for 48 hours, to obtain a modified phenolic resin; Further, the usage ratio of vinyltrimethoxysilane, ethanol, intermediate, and 9,10-dihydro-9-oxa-10-phosphaphenanthrene-10-oxide is 5.93-11.86 g: 100-200 mL: 0.12-0.24 mol: 0.04-0.08 mol; Finally, the siloxy group of vinyl trimethoxysilane, a silane coupling agent, was hydrolyzed into silanol group, which reacted with the hydroxyl group of the intermediate, and then the carbon-carbon double bond of vinyl trimethoxysilane reacted with 9,10-dihydro-9-oxa-10-phosphaphenanthrene-10-oxide to obtain the modified phenolic resin.

[0007] The present invention also provides a method for preparing a highly wear-resistant resin abrasive disc, which specifically comprises the following steps: S1, mixing microcrystalline diamond, white corundum, zirconium corundum, modified toughening agent, magnesium oxide and modified phenolic resin uniformly to obtain a mixed material; S2. The mixed material is naturally dried to a moisture content of less than 1%, and then pressed into shape and demolded at a pressing pressure of 5 MPa. Finally, it is sintered and cured at 150-180°C for 120 minutes to obtain a highly wear-resistant resin abrasive disc.

[0008] Beneficial effects of the present invention: The high wear-resistant resin grinding disc of the present invention has good toughening effect and reduces brittleness, and also has excellent high temperature resistance and flame retardant effect, thereby extending the service life of the material.

[0009] In the modified toughening agent prepared by the present invention, the modified boron nitride can promote the curing of phenolic resin, improve the curing stability and the storage modulus after curing, significantly reduce the curing defects and enhance the toughness; in view of the problem that cracks are easily generated due to curing shrinkage after the phenolic resin is cured, the flexible chain on the surface of the modified toughening agent contains amino groups, which are cross-linked with the phenolic hydroxyl groups of the phenolic resin, reduce the cross-linking density of the phenolic resin itself, and enhance the interface bonding force; in addition, the modified toughening agent has good compatibility with the phenolic resin, can disperse the energy during stress transmission in the phenolic resin, effectively improve the stress transmission efficiency, and then improve the tensile strength to achieve the toughening effect; at the same time, the carboxyl-terminated nitrile rubber in the modified toughening agent contains a flexible chain segment, and its flexibility and high elasticity are helpful to absorb and disperse external forces, reduce the risk of rupture of the phenolic resin when it is impacted, and improve the toughness and tensile strength of the phenolic resin; in addition, the introduction of dopamine increases the spacing between boron nitride nanosheets, weakens the high van der Waals attraction at the nanoscale, and effectively prevents the agglomeration of boron nitride sheets.

[0010] The intermediate of the modified phenolic resin prepared by the present invention shows better heat resistance, instantaneous high temperature resistance and mechanical properties than traditional phenolic resin by introducing boron element into the molecular structure of phenolic resin. Boron element forms a three-dimensional network structure during the curing process, which gives it thermosetting and good heat resistance. At the same time, vinyltrimethoxysilane enhances the thermal stability of the resin due to its high Si-O bond energy and high molecular flexibility. The addition of organic silicon not only reduces the internal stress of the phenolic resin, but also improves the toughness and high temperature resistance of the phenolic resin. In addition, silicon and boron form silicon carbide and boron carbide protective layers under high temperature, which effectively and synergistically prevent the material from further thermal decomposition, thereby improving the heat resistance of the material. In addition, the phosphorus-nitrogen flame retardant 9,10-dihydro-9-oxa-10-phosphaphenanthrene-10-oxide, as a phosphaphenanthrene compound with high thermal stability, can effectively flame retard in the condensed phase and gas phase, promote the formation of a dense and continuous carbon layer, isolate oxygen and heat exchange, and further enhance the flame retardant effect. DETAILED DESCRIPTION

[0011] The technical solutions in the embodiments of the present invention are described clearly and completely below. Obviously, the described embodiments are only part of the embodiments of the present invention, not all of them. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without creative work are within the scope of protection of the present invention.

[0012] Embodiment 1: A method for preparing a highly wear-resistant resin abrasive disc, comprising the following steps: S1. Weigh the raw materials by weight: 30 parts of microcrystalline diamond, 20 parts of white corundum, 6 parts of zirconium corundum, 5 parts of modified toughening agent, 20 parts of modified phenolic resin, and 3 parts of magnesium oxide; mix the microcrystalline diamond, white corundum, zirconium corundum, modified toughening agent, magnesium oxide and modified phenolic resin uniformly to obtain a mixed material; S2, the mixed material is naturally dried to a moisture content of less than 1%, and then pressed into shape and demolded at a pressing pressure of 5 MPa, and finally sintered and cured at 150° C. for 120 min to obtain a highly wear-resistant resin abrasive disc; The modified toughening agent is prepared by the following method: Step A1: 60 mL of isopropanol and 90 mL of deionized water were mixed evenly, 2 g of hexagonal boron nitride powder was added, ultrasonic reaction was performed for 8 h, centrifuged at 5000 r / min for 30 min, the supernatant after centrifugation was centrifuged at 12000 r / min for 30 min, vacuum dried at 60° C. for 20 h, and ground to obtain modified boron nitride; Step A2: 1 g of modified boron nitride and 1.34 g of tris(hydroxymethyl)aminomethane were mixed, and ultrasonicated at a power of 200 W for 3 min, and then 0.3 g of dopamine hydrochloride was added, and the mixture was stirred for 24 h, washed, filtered, and dried at 60° C. for 20 h to obtain a compound; Step A3: 0.02 mol of carboxyl-terminated nitrile rubber, 0.01 mol of the compound and 0.01 g of dioctyl phthalate were mixed and stirred evenly, and then 0.06 g of hydrofluoric acid was added and mixed, and the mixture was reacted at 120° C. for 6 h, cooled, and distilled to obtain a modified toughening agent; The modified phenolic resin is prepared by the following method: Step B1: 4.7 g of phenol, 0.6 mL of ammonia solution and 2.3 g of formaldehyde were mixed evenly, reacted in an oil bath at 70°C for 2 h with stirring, and vacuum distilled at 70°C and a vacuum degree of -0.08 MPa, and then 0.93 g of boric acid was added and mixed, and the reaction was continued at 100°C for 80 min, and vacuum distilled to obtain an intermediate. The concentration of the ammonia solution was 25%; Step B2: Mix 5.93 g of vinyltrimethoxysilane and 100 mL of ethanol, stir at 80 ° C for 10 h, cool to room temperature, filter, wash, add 0.12 mol of the intermediate, react for 1 h, add 0.04 mol of 9,10-dihydro-9-oxa-10-phosphaphenanthrene-10-oxide, stir for 12 h, and continuously cure at each temperature of 100 ° C, 120 ° C, 150 ° C and 180 ° C for 2 h, and dry at 60 ° C for 48 h to obtain a modified phenolic resin.

[0013] Embodiment 2: A method for preparing a highly wear-resistant resin abrasive disc, comprising the following steps: S1. Weigh the raw materials by weight: 35 parts of microcrystalline diamond, 25 parts of white corundum, 8 parts of zirconium corundum, 6.5 parts of modified toughening agent, 22.5 parts of modified phenolic resin, and 4 parts of magnesium oxide; mix the microcrystalline diamond, white corundum, zirconium corundum, modified toughening agent, magnesium oxide and modified phenolic resin uniformly to obtain a mixed material; S2, the mixed material is naturally dried to a moisture content of less than 1%, and then pressed into shape and demolded at a pressing pressure of 5 MPa, and finally sintered and cured at 165° C. for 120 min to obtain a highly wear-resistant resin abrasive disc; The modified toughening agent is prepared by the following method: Step A1: 80 mL of isopropanol and 120 mL of deionized water were mixed evenly, 2.5 g of hexagonal boron nitride powder was added, ultrasonic reaction was performed for 8 h, centrifuged at 5000 r / min for 30 min, the supernatant after centrifugation was centrifuged at 12000 r / min for 30 min, vacuum dried at 60° C. for 20 h, and ground to obtain modified boron nitride; Step A2: 1 g of modified boron nitride and 1.68 g of tris(hydroxymethyl)aminomethane were mixed, and ultrasonicated at a power of 200 W for 6.5 min, and then 0.3 g of dopamine hydrochloride was added, and the mixture was stirred for 24 h, washed, filtered, and dried at 60° C. for 20 h to obtain a compound; Step A3: 0.02 mol of carboxyl-terminated nitrile rubber, 0.01 mol of the compound and 0.02 g of dioctyl phthalate were mixed and stirred evenly, and then 0.06 g of hydrofluoric acid was added and mixed, and the mixture was reacted at 120° C. for 6 h, cooled, and distilled to obtain a modified toughening agent; The modified phenolic resin is prepared by the following method: Step B1: 7.05 g of phenol, 0.9 mL of ammonia solution and 3.45 g of formaldehyde were mixed evenly, placed in an oil bath at 70°C, stirred for reaction for 2 h, and subjected to reduced pressure distillation at 70°C and a vacuum degree of -0.08 MPa. 0.93 g of boric acid was then added and mixed, and the reaction was continued at 100°C for 80 min. The intermediate was obtained by reduced pressure distillation. The concentration of the ammonia solution was 25%; Step B2: Mix 8.90 g of vinyltrimethoxysilane and 150 mL of ethanol, stir at 80 ° C for 10 h, cool to room temperature, filter, wash, add 0.18 mol of the intermediate, react for 1 h, add 0.06 mol of 9,10-dihydro-9-oxa-10-phosphaphenanthrene-10-oxide, stir for 12 h, and continuously cure at each temperature of 100 ° C, 120 ° C, 150 ° C and 180 ° C for 2 h, and dry at 60 ° C for 48 h to obtain a modified phenolic resin.

[0014] Embodiment 3: A method for preparing a highly wear-resistant resin abrasive disc, comprising the following steps: S1. Weigh the raw materials by weight: 40 parts of microcrystalline diamond, 30 parts of white corundum, 10 parts of zirconium corundum, 8 parts of modified toughening agent, 25 parts of modified phenolic resin, and 5 parts of magnesium oxide; mix the microcrystalline diamond, white corundum, zirconium corundum, modified toughening agent, magnesium oxide and modified phenolic resin uniformly to obtain a mixed material; S2, the mixed material is naturally dried to a moisture content of less than 1%, and then pressed into shape and demolded at a pressing pressure of 5 MPa, and finally sintered and cured at 180° C. for 120 min to obtain a highly wear-resistant resin abrasive disc; The modified toughening agent is prepared by the following method: Step A1: 100 mL of isopropanol and 150 mL of deionized water were mixed evenly, 3 g of hexagonal boron nitride powder was added, ultrasonic reaction was performed for 8 h, centrifuged at 5000 r / min for 30 min, the supernatant after centrifugation was centrifuged at 12000 r / min for 30 min, vacuum dried at 60° C. for 20 h, and ground to obtain modified boron nitride; Step A2: 1 g of modified boron nitride and 2.02 g of tris(hydroxymethyl)aminomethane were mixed, ultrasonicated at a power of 200 W for 10 min, and then 0.3 g of dopamine hydrochloride was added, stirred for 24 h, washed, filtered, and dried at 60° C. for 20 h to obtain a compound; Step A3: 0.02 mol of carboxyl-terminated nitrile rubber, 0.01 mol of the compound and 0.03 g of dioctyl phthalate were mixed and stirred evenly, and then 0.06 g of hydrofluoric acid was added and mixed, and the mixture was reacted at 120° C. for 6 h, cooled, and distilled to obtain a modified toughening agent; The modified phenolic resin is prepared by the following method: Step B1: 9.4 g of phenol, 1.2 mL of ammonia solution and 4.6 g of formaldehyde were mixed evenly, reacted in an oil bath at 70°C for 2 h with stirring, and vacuum distilled at 70°C and a vacuum degree of -0.08 MPa, and then 0.93 g of boric acid was added and mixed, and the reaction was continued at 100°C for 80 min, and vacuum distilled to obtain an intermediate. The concentration of the ammonia solution was 25%; Step B2: Mix 11.86 g of vinyltrimethoxysilane and 200 mL of ethanol, stir at 80 ° C for 10 h, cool to room temperature, filter, wash, add 0.24 mol of the intermediate, react for 1 h, add 0.08 mol of 9,10-dihydro-9-oxa-10-phosphaphenanthrene-10-oxide, stir for 12 h, and continuously cure at each temperature of 100 ° C, 120 ° C, 150 ° C and 180 ° C for 2 h, and dry at 60 ° C for 48 h to obtain a modified phenolic resin.

[0015] Comparative Example 1: This comparative example is a highly wear-resistant resin abrasive disc. The difference from Example 3 is that an equal amount of nitrile rubber powder is used to replace the modified toughening agent prepared in Example 3, and the rest are the same.

[0016] Comparative Example 2: This comparative example is a highly wear-resistant resin abrasive disc. The difference from Example 3 is that an equal amount of phenolic resin is used to replace the modified phenolic resin prepared in Example 3, and the rest are the same.

[0017] Performance test: The high wear-resistant resin grinding discs prepared in Examples 1-3 and Comparative Examples 1-2 were tested for flexural strength using standard GB / T2567-2021, and for tensile strength using standard GB / T1040.1-2006; the combustion performance was tested using standard GB 8624-2012; and the grinding efficiency was tested using standard GB / T 24412-2009; the test results are shown in Table 1 below.

[0018] Table 1 Product performance test results of Examples 1-3 and Comparative Examples 1-2:

[0019] It can be seen from the test data in Table 1 that the high wear-resistant resin grinding disc prepared by the present invention has a good toughening effect. It can also be seen from the above table that the high wear-resistant resin grinding disc prepared by the present invention has high temperature resistance and flame retardant effects, which prolongs the service life of the material.

[0020] The above contents are merely examples and explanations of the concept of the present invention. The technicians in this technical field may make various modifications or additions to the specific embodiments described or replace them in a similar manner. As long as they do not deviate from the concept of the invention or exceed the scope defined by the claims, they should all fall within the protection scope of the present invention.

Claims

1. A method for preparing a highly wear-resistant resin abrasive disc, characterized in that: The specific steps include: S1. Weigh the raw materials by weight: 30-40 parts of microcrystalline diamond, 20-30 parts of white corundum, 6-10 parts of zirconium corundum, 5-8 parts of modified toughening agent, 20-25 parts of modified phenolic resin, and 3-5 parts of magnesium oxide; mix the microcrystalline diamond, white corundum, zirconium corundum, modified toughening agent, magnesium oxide and modified phenolic resin uniformly to obtain a mixed material; S2, the mixed material is naturally dried to a moisture content of less than 1%, and then pressed into shape and demolded at a pressing pressure of 5MPa, and finally sintered and cured at 150-180°C for 120min to obtain a highly wear-resistant resin abrasive disc; The modified toughening agent is prepared by the following method: Step A1: isopropanol and deionized water are mixed evenly, hexagonal boron nitride powder is added, ultrasonic reaction is performed for 8 hours, centrifuged at a speed of 5000 r / min for 30 minutes, and then the supernatant after centrifugation is centrifuged at a speed of 12000 r / min for 30 minutes, vacuum dried at 60°C for 20 hours, and ground to obtain modified boron nitride; Step A2: Modified boron nitride and tris(hydroxymethyl)aminomethane were mixed, ultrasonicated at a power of 200 W for 3-10 min, dopamine hydrochloride was added, stirred for 24 h, washed, filtered, and dried at 60° C. for 20 h to obtain a compound; Step A3: Mix the carboxyl-terminated nitrile rubber, the compound and dioctyl phthalate and stir evenly, then add hydrofluoric acid and mix, react at 120° C. for 6 hours, cool, and distill to obtain a modified toughening agent.

2. The method for preparing a highly wear-resistant resin abrasive disc according to claim 1, characterized in that: In step A1, the usage ratio of isopropanol, deionized water and hexagonal boron nitride powder is 60-100 mL: 90-150 mL: 2-3 g.

3. The method for preparing a highly wear-resistant resin abrasive disc according to claim 1, characterized in that: In step A2, the mass ratio of modified boron nitride, tris(hydroxymethyl)aminomethane, and dopamine hydrochloride is 1 g:1.34-2.02 g:0.3 g.

4. The method for preparing a highly wear-resistant resin abrasive disc according to claim 1, characterized in that: In step A3, the usage ratio of the terminal carboxyl nitrile rubber, the compound, dioctyl phthalate and hydrofluoric acid is 0.02 mol: 0.01 mol: 0.01-0.03 g: 0.06 g.

5. The method for preparing a highly wear-resistant resin abrasive disc according to claim 1, characterized in that: The modified phenolic resin is prepared by the following method: Step B1: Phenol, ammonia solution and formaldehyde were mixed evenly, reacted in an oil bath at 70°C for 2 hours with stirring, and vacuum distilled at 70°C and a vacuum degree of -0.08MPa, and then boric acid was added and mixed, and the reaction was continued at 100°C for 80 minutes, and vacuum distilled to obtain an intermediate; Step B2: Vinyltrimethoxysilane and ethanol are mixed, stirred at 80°C for 10 hours, cooled to room temperature, filtered, washed, added with the intermediate, reacted for 1 hour, then added with 9,10-dihydro-9-oxa-10-phosphaphenanthrene-10-oxide, stirred for 12 hours, cured continuously at each temperature of 100°C, 120°C, 150°C and 180°C for 2 hours, dried at 60°C for 48 hours, to obtain a modified phenolic resin.

6. The method for preparing a highly wear-resistant resin abrasive disc according to claim 5, characterized in that: In step B1, the dosage ratio of phenol, ammonia solution, formaldehyde and boric acid is 4.7-9.4 g: 0.6-1.2 mL: 2.3-4.6 g: 0.93 g, and the concentration of ammonia solution is 25%.

7. The method for preparing a highly wear-resistant resin abrasive disc according to claim 5, characterized in that: In step B2, the usage ratio of vinyltrimethoxysilane, ethanol, intermediate, and 9,10-dihydro-9-oxa-10-phosphaphenanthrene-10-oxide is 5.93-11.86 g: 100-200 mL: 0.12-0.24 mol: 0.04-0.08 mol.

8. A highly wear-resistant resin abrasive disc, characterized in that: The invention is prepared by the method for preparing a highly wear-resistant resin abrasive disc according to any one of claims 1 to 7.

Images