A highly wear-resistant resin grinding disc and its preparation method

Abstract

The present invention relates to a highly wear-resistant resin grinding disc and a preparation method thereof, belonging to the technical field of polymer materials. The highly wear-resistant resin grinding disc comprises, by weight: 30-40 parts of microcrystalline diamond, 20-30 parts of white fused alumina, 6-10 parts of zirconium corundum, 5-8 parts of a modified toughening agent, 20-25 parts of a modified phenolic resin, and 3-5 parts of magnesium oxide; in the modified toughening agent, modified boron nitride promotes resin curing, amino groups crosslink with the resin, enhancing the interfacial bonding force to achieve toughening, carboxyl-terminated nitrile rubber improves the toughness of the resin, and dopamine increases the spacing between boron nitrides, weakening the van der Waals force and preventing boron nitride agglomeration; the modified phenolic resin introduces boron elements, forming a three-dimensional network structure during curing, endowing good heat resistance, and vinyltrimethoxysilane enhances the thermal stability due to the high bond energy of the Si-O bond and large molecular flexibility; the highly wear-resistant resin grinding disc prepared by the present invention not only has a good toughening effect, but also has excellent high-temperature resistance and flame retardant effects.

Description

Technical Field

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

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

[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 resin abrasive tools, resulting in poor grinding performance, rapid attenuation of abrasive tool performance, short service life, and limited use efficiency. In addition, although phenolic resin grinding discs have a certain flame retardancy, with the improvement of actual application requirements, their own flame retardancy no longer meets the needs. Therefore, the research and development of highly wear-resistant resin grinding discs with excellent performance have 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 grinding disc and a preparation method thereof.

[0005] The purpose of the present invention can be achieved by the following technical solutions:

[0006] A highly wear-resistant resin grinding disc, comprising the following raw materials in parts by weight: 30 - 40 parts of microcrystalline diamond, 20 - 30 parts of white fused alumina, 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.

[0007] The modified toughening agent is prepared by the following method:

[0008] Step A1: Mix isopropanol and deionized water evenly, add hexagonal boron nitride powder, react ultrasonically for 8 h, centrifuge at a speed of 5000 r / min for 30 min, then take the supernatant after centrifugation and centrifuge at a speed of 12000 r / min for 30 min, and dry in vacuum at 60 °C for 20 h, and grind to obtain modified boron nitride;

[0009] Further, the dosage ratio of isopropanol, deionized water, and hexagonal boron nitride powder is 60 - 100 mL: 90 - 150 mL: 2 - 3 g;

[0010] First, use the ultrasonic exfoliation method to exfoliate hexagonal boron nitride powder into nano-boron nitride to obtain modified boron nitride;

[0011] Step A2: Mix the modified boron nitride and tris(hydroxymethyl)aminomethane, sonicate at a power of 200 W for 3 - 10 min, then add dopamine hydrochloride, stir for 24 h, wash, filter, and dry at 60 °C for 20 h to obtain the compound;

[0012] Further, the mass ratio of the modified boron nitride, tris(hydroxymethyl)aminomethane, and dopamine hydrochloride is 1 g : 1.34 - 2.02 g : 0.3 g;

[0013] Secondly, utilize the oxidation of dopamine to form polydopamine and perform surface modification on the modified boron nitride to obtain a compound containing hydroxyl groups;

[0014] 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 h, cool, distill, and obtain the modified toughening agent;

[0015] Further, the dosage 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;

[0016] Finally, utilize the reaction between the hydroxyl groups of the compound and the carboxyl groups of the carboxyl-terminated nitrile rubber to generate the modified toughening agent;

[0017] The modified phenolic resin is prepared by the following method:

[0018] Step B1: Mix phenol, ammonia water solution, and formaldehyde evenly, perform an oil bath at 70 °C, stir and react for 2 h, perform vacuum distillation at a temperature of 70 °C and a vacuum degree of -0.08 MPa, then add boric acid and mix, continue to react at 100 °C for 80 min, and perform vacuum distillation to obtain the intermediate;

[0019] Further, the dosage ratio of phenol, ammonia water 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 the ammonia water solution is 25%;

[0020] Firstly, utilize the reaction between phenol and formaldehyde to generate phenolic resin, and then utilize the reaction between the hydroxyl groups of boric acid and the hydroxyl groups of the phenolic resin to generate the intermediate;

[0021] Step B2: Mix vinyltrimethoxysilane and ethanol, stir at 80 °C for 10 h, cool to room temperature, filter and wash, add the intermediate, react for 1 h, then add 9,10-dihydro-9-oxa-10-phosphaphenanthrene-10-oxide, stir for 12 h, and perform continuous curing at 100 °C, 120 °C, 150 °C, and 180 °C for 2 h each, and dry at 60 °C for 48 h to obtain the modified phenolic resin;

[0022] Furthermore, the dosage 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;

[0023] Finally, the siloxy group of the silane coupling agent vinyltrimethoxysilane is hydrolyzed into silanol groups, which react with the hydroxyl groups of the intermediate. Then, the carbon-carbon double bond of vinyltrimethoxysilane reacts with 9,10-dihydro-9-oxa-10-phosphaphenanthrene-10-oxide to prepare the modified phenolic resin.

[0024] The present invention also provides a method for preparing a highly wear-resistant resin grinding disc, which specifically includes the following steps:

[0025] S1. Mix microcrystalline diamond, white fused alumina, zirconium corundum, modified toughening agent, magnesium oxide, and modified phenolic resin evenly to obtain a mixed material;

[0026] S2. Naturally dry the mixed material until the moisture content is lower than 1%, then press it into shape and demold it. The pressing pressure is 5 MPa. Finally, sinter and cure it at 150 - 180 °C for 120 min to obtain the highly wear-resistant resin grinding disc.

[0027] Advantages of the present invention:

[0028] The highly wear-resistant resin grinding disc of the present invention has a good toughening effect, reduces brittleness, and at the same time has excellent high-temperature resistance and flame retardancy effects, extending the service life of the material.

[0029] In the modified toughening agent prepared by the present invention, modified boron nitride can promote the curing of phenolic resin, improve the curing stability and storage modulus after curing, significantly reduce curing defects and enhance toughness; for the problem that cracks are easily generated due to curing shrinkage after the curing of phenolic resin, the flexible chain on the surface of the modified toughening agent contains amino groups, which crosslink with the phenolic hydroxyl groups of phenolic resin, reducing the crosslinking density of phenolic resin itself and enhancing the interfacial bonding force. In addition, the good compatibility between the modified toughening agent and phenolic resin can disperse the energy during stress transfer in phenolic resin, effectively improving the stress transfer efficiency, thereby enhancing the tensile strength and achieving the toughening effect; at the same time, the carboxyl-terminated nitrile rubber in the modified toughening agent contains flexible chain segments, and its flexibility and high elasticity help to absorb and disperse external forces, reducing the risk of cracking when phenolic resin is impacted, and improving the toughness and tensile strength of phenolic resin; in addition, the introduction of dopamine increases the spacing between boron nitride nanosheets, weakening the high van der Waals force at the nanoscale and effectively preventing the aggregation of boron nitride sheets.

[0030] The intermediate of the modified phenolic resin prepared by the present invention shows more excellent heat resistance, instantaneous high-temperature resistance and mechanical properties compared with traditional phenolic resins by introducing boron elements into the molecular structure of phenolic resins. Boron elements form a three-dimensional network structure during the curing process, endowing it with thermosetting and good heat resistance. At the same time, vinyltrimethoxysilane has a high Si-O bond energy and large molecular flexibility, enhancing the thermal stability of the resin. The addition of organosilicon not only reduces the internal stress of phenolic resin, but also improves the toughness and high-temperature resistance of phenolic resin. In addition, silicon and boron form a silicon carbide and boron carbide protective layer under high-temperature action, effectively synergistically preventing further thermal decomposition of the material, 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 retard flame 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 implementation mode

[0031] The technical solutions in the embodiments of the present invention will be clearly and completely described below. Obviously, the described embodiments are only a part of the embodiments of the present invention, rather than all the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by those of ordinary skill in the art without creative efforts shall fall within the protection scope of the present invention.

[0032] Example 1: A preparation method of a highly wear-resistant resin grinding disc specifically includes the following steps:

[0033] S1. Weigh the raw materials by weight: 30 parts of microcrystalline diamond, 20 parts of white fused alumina, 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 fused alumina, zirconium corundum, modified toughening agent, magnesium oxide and modified phenolic resin evenly to obtain a mixed material.

[0034] S2. Naturally dry the mixed material until the moisture content is lower than 1%, then press it into shape and demold. The pressing pressure is 5 MPa, and finally sintering and curing treatment is carried out at 150 °C for 120 min to obtain a highly wear-resistant resin grinding disc.

[0035] The modified toughening agent is prepared by the following method:

[0036] Step A1: Mix 60 mL of isopropanol and 90 mL of deionized water evenly, add 2 g of hexagonal boron nitride powder, carry out ultrasonic reaction for 8 h, centrifuge at a speed of 5000 r / min for 30 min, then take the supernatant after centrifugation and centrifuge at a speed of 12000 r / min for 30 min, and vacuum dry at 60 °C for 20 h, and grind to obtain modified boron nitride.

[0037] Step A2: Mix 1 g of modified boron nitride and 1.34 g of tris(hydroxymethyl)aminomethane, sonicate for 3 min at a power of 200 W, then add 0.3 g of dopamine hydrochloride, stir for 24 h, wash and filter, and dry at 60 °C for 20 h to obtain the compound;

[0038] Step A3: Mix 0.02 mol of carboxyl-terminated nitrile rubber, 0.01 mol of the compound and 0.01 g of dioctyl phthalate and stir evenly, then add 0.06 g of hydrofluoric acid and mix, react at 120 °C for 6 h, cool, and distill to obtain the modified toughening agent;

[0039] The modified phenolic resin is prepared by the following method:

[0040] Step B1: Mix 4.7 g of phenol, 0.6 mL of ammonia water solution and 2.3 g of formaldehyde evenly, carry out an oil bath at 70 °C, stir and react for 2 h, carry out vacuum distillation at a temperature of 70 °C and a vacuum degree of -0.08 MPa, then add 0.93 g of boric acid and mix, continue to react at 100 °C for 80 min, and carry out vacuum distillation to obtain the intermediate. The concentration of the ammonia water solution is 25%;

[0041] 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 and wash, add 0.12 mol of the intermediate, react for 1 h, then add 0.04 mol of 9,10-dihydro-9-oxa-10-phosphaphenanthrene-10-oxide, stir for 12 h, and cure continuously for 2 h at each of the temperatures of 100 °C, 120 °C, 150 °C and 180 °C, and dry at 60 °C for 48 h to obtain the modified phenolic resin.

[0042] Example 2: A preparation method of a high wear-resistant resin grinding disc, specifically including the following steps:

[0043] S1. Weigh the raw materials by weight: 35 parts of microcrystalline diamond, 25 parts of white fused alumina, 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 fused alumina, zirconium corundum, modified toughening agent, magnesium oxide and modified phenolic resin evenly to obtain the mixed material;

[0044] S2. Naturally dry the mixed material until the moisture content is lower than 1%, then press and mold, demold, the pressing pressure is 5 MPa, and finally sinter and cure at 165 °C for 120 min to obtain the high wear-resistant resin grinding disc;

[0045] The modified toughening agent is prepared by the following method:

[0046] Step A1: Mix 80 mL of isopropanol and 120 mL of deionized water evenly, add 2.5 g of hexagonal boron nitride powder, react ultrasonically for 8 h, centrifuge at a speed of 5000 r / min for 30 min, then take the supernatant after centrifugation and centrifuge it at a speed of 12000 r / min for 30 min, dry it in vacuum at 60 °C for 20 h, and grind to obtain modified boron nitride;

[0047] Step A2: Mix 1 g of modified boron nitride and 1.68 g of tris(hydroxymethyl)aminomethane, ultrasonically react at a power of 200 W for 6.5 min, then add 0.3 g of dopamine hydrochloride, stir for 24 h, wash and filter, and dry at 60 °C for 20 h to obtain a compound;

[0048] Step A3: Mix 0.02 mol of carboxyl-terminated nitrile rubber, 0.01 mol of the compound and 0.02 g of dioctyl phthalate evenly, then add 0.06 g of hydrofluoric acid and mix, react at 120 °C for 6 h, cool, and distill to obtain a modified toughening agent;

[0049] The modified phenolic resin is prepared by the following method:

[0050] Step B1: Mix 7.05 g of phenol, 0.9 mL of ammonia water solution and 3.45 g of formaldehyde evenly, perform an oil bath at 70 °C, stir and react for 2 h, perform vacuum distillation at a temperature of 70 °C and a vacuum degree of -0.08 MPa, then add 0.93 g of boric acid and mix, continue to react at 100 °C for 80 min, and perform vacuum distillation to obtain an intermediate. The concentration of the ammonia water solution is 25%;

[0051] 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 and wash, add 0.18 mol of the intermediate, react for 1 h, then add 0.06 mol of 9,10-dihydro-9-oxa-10-phosphaphenanthrene-10-oxide, stir for 12 h, and cure continuously for 2 h at each temperature of 100 °C, 120 °C, 150 °C and 180 °C, and dry at 60 °C for 48 h to obtain the modified phenolic resin.

[0052] Example 3: A preparation method of a highly wear-resistant resin grinding disc, specifically including the following steps:

[0053] S1. Weigh raw materials by weight: 40 parts of microcrystalline diamond, 30 parts of white fused alumina, 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 fused alumina, zirconium corundum, modified toughening agent, magnesium oxide and modified phenolic resin evenly to obtain a mixed material;

[0054] S2. Naturally dry the mixed materials until the moisture content is lower than 1%, then press them into shape and demold. The pressing pressure is 5 MPa. Finally, sinter and cure at 180 °C for 120 min to obtain a highly wear-resistant resin grinding disc.

[0055] The modified toughening agent is prepared by the following method:

[0056] Step A1: Mix 100 mL of isopropyl alcohol and 150 mL of deionized water evenly, add 3 g of hexagonal boron nitride powder, react ultrasonically for 8 h, centrifuge at a speed of 5000 r / min for 30 min, then take the supernatant after centrifugation and centrifuge at a speed of 12000 r / min for 30 min, and dry in vacuum at 60 °C for 20 h, and grind to obtain modified boron nitride.

[0057] Step A2: Mix 1 g of modified boron nitride and 2.02 g of tris(hydroxymethyl)aminomethane, ultrasonically react at a power of 200 W for 10 min, then add 0.3 g of dopamine hydrochloride, stir for 24 h, wash and filter, and dry at 60 °C for 20 h to obtain a compound.

[0058] Step A3: Mix 0.02 mol of carboxyl-terminated nitrile rubber, 0.01 mol of the compound and 0.03 g of dioctyl phthalate evenly, then add 0.06 g of hydrofluoric acid and mix, react at 120 °C for 6 h, cool, and distill to obtain the modified toughening agent.

[0059] The modified phenolic resin is prepared by the following method:

[0060] Step B1: Mix 9.4 g of phenol, 1.2 mL of ammonia water solution and 4.6 g of formaldehyde evenly, perform an oil bath at 70 °C, stir and react for 2 h, perform vacuum distillation at a temperature of 70 °C and a vacuum degree of -0.08 MPa, then add 0.93 g of boric acid and mix, continue to react at 100 °C for 80 min, and perform vacuum distillation to obtain an intermediate. The concentration of the ammonia water solution is 25%.

[0061] 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 and wash, add 0.24 mol of the intermediate, react for 1 h, then add 0.08 mol of 9,10-dihydro-9-oxa-10-phosphaphenanthrene-10-oxide, stir for 12 h, and continuously cure at 100 °C, 120 °C, 150 °C and 180 °C for 2 h each, and dry at 60 °C for 48 h to obtain the modified phenolic resin.

[0062] Comparative Example 1: This comparative example is a highly wear-resistant resin grinding disc. The difference from Example 3 is that an equal amount of nitrile rubber powder is used instead of the modified toughening agent prepared in Example 3, and the rest are the same.

[0063] Comparative Example 2: This comparative example is a highly wear-resistant resin grinding disc. The difference from Example 3 is that phenolic resin of equal amount is used to replace the modified phenolic resin prepared in Example 3, and the rest are the same.

[0064] Performance test: The highly wear-resistant resin grinding discs prepared in Examples 1-3 and Comparative Examples 1-2 were used to test the flexural strength according to the standard GB / T 2567-2021, and the tensile strength was tested according to the standard GB / T 1040.1-2006; the combustion performance was tested according to GB 8624-2012; the grinding efficiency was tested according to the standard GB / T 24412-2009; the test results are shown in Table 1 below.

[0065] Table 1 Product performance test results of Examples 1-3 and Comparative Examples 1-2:

[0066]

[0067] It can be seen from the data tested in Table 1 that the highly 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 highly wear-resistant resin grinding disc prepared by the present invention has high temperature resistance and flame retardant effects, and can extend the service life of the material.

[0068] The above content is only an example and explanation of the concept of the present invention. Those skilled in the art of this technology can make various modifications or supplements to the described specific embodiments or use similar methods to replace them, as long as they do not deviate from the concept of the invention or exceed the scope defined by this claim book, they should all belong to 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 high wear-resistant resin abrasive disc is prepared by the preparation method of any one of claims 1 to 7.

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