Environment-friendly coating for sandpaper and production method thereof

Abstract

The application relates to the technical field of sandpaper coating, and in particular to an environment-friendly sandpaper coating and a production method thereof. The environment-friendly sandpaper coating comprises, in mass parts, 20-50 parts of hard stearate, 3-6 parts of an anti-sticking agent, 8-20 parts of an organic silicon acrylic acid polymer, 3-10 parts of modified graphene, 4-6 parts of a dispersing agent and 50-80 parts of water. The organic silicon acrylic acid polymer is prepared by polymerization reaction of halogenated polysiloxane and a carbon-carbon double bond-containing monomer. The modified graphene is prepared by modifying nano-oxidized graphene with a surfactant. The organic silicon acrylic acid polymer and the modified graphene are used together, the heat conduction / heat dissipation rate of a film layer is improved, the water resistance of the film layer is enhanced, the too-fast migration and too-fast falling of small molecular substances in the film layer under high temperature are reduced, the cohesion of the film layer and the bonding force between the film layer and abrasive materials are enhanced, various performances are mutually enhanced, and the sandpaper prepared by using the environment-friendly sandpaper coating has excellent grinding capacity and anti-blocking performance.

Description

Technical Field

[0001] This application relates to the technical field of sandpaper coatings, and in particular to an environmentally friendly sandpaper coating and its production method. Background Technology

[0002] Sandpaper, also known as abrasive paper, is a material used for grinding. It is made by bonding abrasive particles to flexible materials such as cloth and paper with a sandpaper coating. It is widely used in grinding automobiles, ship hulls, machine tools, as well as polishing electronic products and precision instruments.

[0003] Traditional solvent-based sandpaper coatings are environmentally unfriendly, while water-soluble coatings suffer from poor adhesion between the coating and the abrasive, as well as poor water resistance. Sandpaper with water-soluble coatings is prone to abrasive shedding during use, leading to uneven sanding. Furthermore, the heat and static electricity generated during sanding reduce chip removal, causing clogging on the sandpaper surface, affecting grinding efficiency and lifespan, and in severe cases, even burning the workpiece. Summary of the Invention

[0004] To address the problems of poor adhesion between existing environmentally friendly sandpaper coatings and abrasives, resulting in sandpaper that is prone to clogging and has poor water resistance, this application provides an environmentally friendly sandpaper coating and its production method.

[0005] Firstly, this application provides an environmentally friendly coating for sandpaper.

[0006] An environmentally friendly coating for sandpaper, comprising, by weight, 20-50 parts of hard stearate, 3-6 parts of anti-blocking agent, 8-20 parts of organosilicon acrylic polymer, 3-10 parts of modified graphene, 4-6 parts of dispersant, and 50-80 parts of water.

[0007] The organosilicon acrylic polymer was prepared by polymerization of halogenated polysiloxane with a monomer containing carbon-carbon double bonds.

[0008] The modified graphene was prepared by modifying nano-graphene oxide with surfactants.

[0009] By adopting the above technical solution and using modified graphene and organosilicon acrylic polymer in combination, the grinding amount and anti-clogging performance of sandpaper prepared with the environmentally friendly sandpaper coating of this application are improved.

[0010] Sandpaper generates a lot of heat during the sanding process. The accumulation of heat will reduce the cohesion of the coating on the sandpaper surface and increase its adhesion. During wet sanding, water evaporation can reduce the temperature of the sandpaper surface and improve sanding efficiency. However, during wet sanding, the coating on the sandpaper surface is subjected to water and mechanical force, causing the coating to peel off too quickly, which reduces the service life of the sandpaper.

[0011] The use of modified graphene in environmentally friendly sandpaper coatings has several advantages. First, it improves the thermal conductivity and heat dissipation rate of the coating, reducing heat accumulation on the coating surface. Second, the strong adsorption properties of modified graphene reduce the migration of small molecules, such as anti-blocking agents, dispersants, and stearic acid, from the film layer to the film surface, thereby improving the water resistance and anti-clogging properties of the prepared sandpaper.

[0012] The organosilicon acrylic polymer is prepared by polymerization of halogenated polysiloxanes and monomers containing carbon-carbon double bonds. The halogens in the halogenated polysiloxanes enhance the cohesiveness of the coating and the bonding force with the abrasive. The siloxane groups in the organosilicon acrylic polymer reduce the surface energy of the film, reduce the influence of water on the film and the hydrolysis of halogens, so that the prepared film has low surface energy, water resistance and strong cohesiveness and bonding force with the abrasive.

[0013] The use of organosilicon acrylic polymers in combination with modified graphene improves the thermal conductivity / heat dissipation rate of the film, enhances the water resistance of the film, reduces the rapid migration and shedding of small molecules in the film at high temperatures, and enhances the cohesion of the film and its bonding force with the abrasive. These multiple properties enhance each other, resulting in sandpaper prepared with environmentally friendly sandpaper coatings that has excellent grinding capacity and anti-clogging performance.

[0014] Preferably, the preparation process of the organosilicon acrylic polymer is as follows:

[0015] The halogenated polysiloxane is prepared by stirring 80-150 parts by weight of double-ended vinyl silicone oil, 30-60 parts by weight of acetone and 180-230 parts by weight of hydrogen halide acetic acid solution at 65-75℃ for 3-4 hours, and then by water extraction and heating evaporation.

[0016] 100 parts by mass of a monomer containing carbon-carbon double bonds, 30-100 parts by mass of a halogenated polysiloxane, 0.1-25 parts by mass of a ligand and 1-300 parts by mass of an organic solvent are mixed, frozen in an ice-salt bath, heated to 50-120°C under nitrogen protection, 0.1-50 parts by mass of a catalyst are added and the mixture is stirred for 10-20 hours to prepare an organosilicon acrylic polymer.

[0017] The carbon-carbon double bond-containing monomer is at least two of the following: methyl methacrylate, styrene, acrylonitrile, ethyl acrylate, butyl acrylate, acrylic acid, methyl acrylate, ethyl acrylate, isobutyl acrylate, hexyl acrylate, isooctyl acrylate, lauryl acrylate, benzyl acrylate, cyclohexyl acrylate, perfluoroalkyl acrylate, hydroxyethyl phosphate acrylate, isobornyl acrylate, tetrahydrofuran methyl acrylate, methacrylic acid, methyl methacrylate, grade ethyl acrylate, butyl methacrylate, isobutyl methacrylate, hexyl methacrylate, isooctyl acrylate, lauryl methacrylate, isobornyl methacrylate, and grade cyclohexyl acrylate.

[0018] By adopting the above technical solution, the organosilicon acrylic polymer is prepared by polymerization reaction of halogenated polysiloxane and carbon-carbon double bond-containing monomers. The halogen in the halogenated polysiloxane enhances the cohesive force of the coating and the bonding force with the abrasive. The siloxane groups in the organosilicon acrylic polymer reduce the surface energy of the film, reduce the influence of water on the film and the hydrolysis of halogen, so that the prepared film has low surface energy, water resistance and strong cohesive force and bonding force with the abrasive.

[0019] Preferably, the viscosity of the dual-terminated vinyl silicone oil is 300-1500 mPa·s, and the dosage is 40-60 parts by weight.

[0020] By adopting the above technical solution and optimizing the viscosity and weight of the dual-end vinyl silicone oil, the grinding amount of sandpaper prepared using environmentally friendly sandpaper coatings can be increased.

[0021] Preferably, the ligand is triphenylphosphine or 2,2-bipyridine; and the catalyst is cuprous bromide or ferrous bromide.

[0022] By adopting the above technical solutions, the ligand increases the molecular weight of the organosilicon acrylic polymer, thereby improving the strength of the film formed by the environmentally friendly sandpaper coating; the catalyst improves the preparation efficiency of the organosilicon acrylic polymer.

[0023] Preferably, the preparation process of the modified graphene is as follows:

[0024] 10-20 parts by weight of nano-graphene oxide, 4-10 parts by weight of surfactant and 8-10 parts by weight of dicyclohexylcarbodiimide were added to 40-60 ml of DMF solvent. After stirring and mixing, ammonia and vitamin C were added in sequence, and the pH was adjusted to 6-7. The mixture was reacted at 60-90℃ for 2-5 h. After washing with water, filtering and drying under vacuum, modified nano-graphene oxide was prepared.

[0025] By adopting the above technical solution, the bonding force between graphene oxide and organosilicon acrylic polymer is improved, thereby enhancing the grinding capacity and anti-clogging performance of sandpaper prepared using the environmentally friendly sandpaper coating of this application.

[0026] Preferably, the surfactant is a silane coupling agent and a cationic fluorocarbon surfactant in a mass ratio of 1:(0.3-1.5); the carbon-carbon double bond-containing monomer is a composition of acrylic acid, acrylonitrile and ethyl acrylate in a mass ratio of (0.4-0.6):(0.8-1.5):2.

[0027] By adopting the above technical solutions, during the preparation of modified graphene, the cationic fluorocarbon surfactant has a strong attraction to the carboxyl groups in the organosilicon acrylic polymer, reducing the aggregation of modified graphene and improving its dispersion performance; the silane coupling agent enhances the bonding force between modified graphene and organosilicon acrylic polymer, and the combined use of cationic fluorocarbon surfactant and silane coupling agent further improves the grinding amount and anti-clogging properties of sandpaper using environmentally friendly sandpaper coatings.

[0028] Preferably, the stearate is at least one of zinc stearate, calcium stearate, aluminum stearate, and magnesium stearate; and the dispersant is at least one of phosphate, sulfonate, and sulfate salt.

[0029] By adopting the above technical solutions, stearates improve the grinding efficiency of environmentally friendly sandpaper coatings; dispersants improve the dispersion effect and stability of raw materials in environmentally friendly sandpaper coatings.

[0030] Preferably, the anti-adhesive is a composition of polymethyltriethoxysilane and oxidized polyethylene wax in a mass ratio of (0.3-0.8):1.

[0031] By adopting the above technical solution, the anti-adhesion agent is used in combination with polymethyltriethoxysilane and oxidized polyethylene wax at a mass ratio of (0.5-0.8):1, which further improves the grinding amount of sandpaper using environmentally friendly sandpaper coating.

[0032] Preferably, the environmentally friendly sandpaper coating further includes 1-8 parts by weight of stearic acid and 2-4 parts by weight of a thickener; the thickener is hydroxyethyl cellulose or hydroxyethyl cellulose ether.

[0033] By adopting the above technical solution, hydroxyethyl cellulose and stearic acid are used in combination in the environmentally friendly sandpaper coating, which further improves the grinding amount of sandpaper using the environmentally friendly sandpaper coating and reduces the coating peeling speed.

[0034] On the other hand, this application provides a production method for preparing the environmentally friendly sandpaper coating of this application.

[0035] A method for producing an environmentally friendly coating for sandpaper includes the following preparation steps:

[0036] After adding the dispersant to water and stirring to mix, add the stearate and anti-sticking agent, and stir at high speed for 40-60 minutes to obtain the first mixed solution;

[0037] The modified graphene was added to the organosilicon acrylic polymer and stirred for 60-80 minutes to prepare a second mixed solution.

[0038] The first mixed solution is added to the second mixed solution and stirred at high speed for 60-90 minutes to prepare a slurry. After grinding, the slurry is used to prepare an environmentally friendly sandpaper coating.

[0039] By adopting the above technical solution, an environmentally friendly sandpaper coating is prepared with low VOC, excellent heat dissipation performance, adhesion and hydrophobicity; the sandpaper prepared with this environmentally friendly sandpaper coating has excellent grinding effect, anti-clogging performance and water resistance.

[0040] In summary, this application has the following beneficial effects:

[0041] 1. An environmentally friendly sandpaper coating, comprising, by weight, 20-50 parts hard stearate, 3-6 parts anti-blocking agent, 8-20 parts organosilicon acrylic polymer, 3-10 parts modified graphene, 4-6 parts dispersant, and 50-80 parts water; the organosilicon acrylic polymer is prepared by polymerization of halogenated polysiloxane with carbon-carbon double bond monomers; the modified graphene is prepared by modifying nano-graphene oxide with surfactants;

[0042] The use of organosilicon acrylic polymers in combination with modified graphene improves the thermal conductivity / heat dissipation rate of the film, enhances the water resistance of the film, reduces the rapid migration and shedding of small molecules in the film at high temperatures, and enhances the cohesion of the film and its bonding force with the abrasive. These multiple properties enhance each other, resulting in sandpaper prepared with environmentally friendly sandpaper coatings that has excellent grinding capacity and anti-clogging performance.

[0043] 1. In this application, the modified graphene is used in combination with a silane coupling agent and a cationic fluorocarbon surfactant; the carbon-carbon double bond monomer in the organosilicon acrylic polymer is a composition of acrylic acid, acrylonitrile and ethyl acrylate in the ratio of (0.4-0.6):(0.8-1.5):2. The use of modified graphene in combination with organosilicon acrylic polymer improves the grinding amount and anti-clogging properties of sandpaper using environmentally friendly sandpaper coatings.

[0044] 2. In this application, an anti-sticking agent (a composition of polymethyltriethoxysilane and oxidized polyethylene wax), stearic acid, hydroxyethyl cellulose and modified graphene are used in combination. The modified graphene and hydroxyethyl cellulose reduce the migration speed and shedding speed of the anti-sticking agent and stearic acid to the film surface during polishing, thereby improving the grinding amount and anti-clogging performance of the sandpaper using environmentally friendly sandpaper coating. Detailed Implementation

[0045] raw material

[0046] Nano-graphene oxide (thickness 0.6-1.2nm, diameter 0.8-2um, purity 99%), cationic fluorocarbon surfactant (model: CF-700, Jinan Qifu New Material Technology Co., Ltd.), dihydroxy-terminated hydroxyl silicone oil (viscosity: 500Mpa·s), divinyl-terminated silicone oil (viscosity: 110Mpa·s, vinyl content 3.1%), hydrogen-containing silicone oil (hydrogen content: 1.1mmol / g, viscosity: 66Mpa·s), quaternary ammonium salt cationic fluorocarbon surfactant (activity value: ≥90%, liquid), hydroxyethyl cellulose (molar substitution degree: 1.8-2.0MS, viscosity MPa.S2%20℃: 50,000), polyvinyl alcohol (item number 2488, 120 mesh, standard GB12010-89, product grade PVA24-88L, superior grade).

[0047] Preparation example of intermediate

[0048] Preparation Example 1-1: An organosilicon acrylic polymer, using raw materials as shown in Table 1, is prepared as follows:

[0049] Preparation of S1 chlorinated polysiloxane: Diethyl vinyl silicone oil, acetone and hydrogen chloride acetic acid solution (hydrogen halide mass percentage of 40%) were reacted at 75℃ and stirring speed of 800±50 r / min for 3 h. The product was extracted with distilled water and then rotary evaporated at 85±5℃ for 6±0.5 h to obtain chlorinated polysiloxane.

[0050] Preparation of S2 organosilicon acrylic polymer: Carbon-carbon double bond monomer, halogenated polysiloxane (chlorinated polysiloxane prepared by step S1), ligand (triphenylphosphine) and acetone were stirred and mixed, then frozen in an ice-salt bath. Under nitrogen protection, the temperature was raised to 120°C, and a catalyst (cuprous bromide) was added and reacted for 10 h to prepare organosilicon acrylic polymer.

[0051] Preparation Examples 1-2 and 1-3 are organosilicon acrylic polymers. The difference between them and Preparation Example 1-1 is that the types of raw materials, the weight of raw materials, and the process parameters are different, as shown in Table 1.

[0052] Table 1. List of raw material types, raw material weights, and preparation process parameters used in the preparation of organosilicon acrylic polymers in Preparation Examples 1-2 and 1-3.

[0053]

[0054]

[0055] Preparation Examples 1-4 to 1-7 are organosilicon acrylic polymers. The difference between them and Preparation Example 1-1 is that the viscosity and weight settings of the dual-end vinyl silicone oil are different, as shown in Table 2.

[0056] Table 2. List of viscosity and weight settings of the dual-end vinyl silicone oil during the preparation of organosilicon acrylic polymers in Preparation Examples 1-4 to 1-7 and Preparation Example 1-1.

[0057] distinguish Preparation Example 1-1 Preparation Examples 1-4 Preparation Examples 1-5 Preparation Examples 1-6 Preparation Examples 1-7 Viscosity / mpa.s 1500 1500 800 300 245 Dosage / kg 150 40 50 60 100

[0058] Preparation Examples 1-8, an organosilicon acrylic polymer, differs from Preparation Example 1-1 in that a composition of aminopropyltriethoxysilane and vinyltrimethoxysilane in a mass ratio of 1:1.5 is used to replace chlorinated polysiloxane in equal amounts.

[0059] Preparation Examples 1-9, an organosilicon acrylic polymer, differs from Preparation Example 1-1 in that it uses an equal amount of dihydroxy-terminated hydroxyl silicone oil, dihydroxyl-terminated vinyl silicone oil, and hydrogen-containing silicone oil in a mass ratio of 2:1:2 to replace chlorinated polysiloxane.

[0060] Preparation Examples 1-10, an organosilicon acrylic polymer, differs from Preparation Example 1-1 in that the carbon-carbon double bond monomer is a composition of acrylic acid, acrylonitrile and ethyl acrylate in a mass ratio of 0.4:0.8:2.

[0061] Preparation Examples 1-11: An organosilicon acrylic polymer, differing from Preparation Example 1-1 in that the monomers containing carbon-carbon double bonds are composed of acrylic acid, acrylonitrile, and ethyl acrylate in a mass ratio of 0.5:1.0:2. Preparation Examples 1-12: An organosilicon acrylic polymer, differing from Preparation Example 1-1 in that the monomers containing carbon-carbon double bonds are composed of acrylic acid, acrylonitrile, and ethyl acrylate in a mass ratio of 0.6:1.5:2.

[0062] Preparation Examples 1-13, an organosilicon acrylic polymer, differs from Preparation Example 1-1 in that the carbon-carbon double bond monomer is a composition of acrylic acid, acrylonitrile and ethyl acrylate in a mass ratio of 0.2:2:2.

[0063] Preparation Examples 1-14, an organosilicon acrylic polymer, differs from Preparation Example 1-1 in that the carbon-carbon double bond monomer is a composition of acrylic acid, acrylonitrile and ethyl acrylate in a mass ratio of 0.8:0.4:2.

[0064] Preparation Examples 1-15, an organosilicon acrylic polymer, differs from Preparation Example 1-1 in that the carbon-carbon double bond monomer is a composition of acrylic acid, acrylonitrile and ethyl acrylate in a mass ratio of 0.4:0.8:2:1.

[0065] Preparation Example 2-1: A modified graphene, using raw materials as shown in Table 3, is prepared as follows:

[0066] Surfactant, nano-graphene oxide, and dicyclohexylcarbodiimide were added to DMF and stirred for 10 min at a stirring speed of 800 r / min. Then, 3 ml of 22% ammonia water was added and stirred for 2 min. After stirring, vitamin C, a reducing agent, was added to adjust the pH to 6.5 ± 0.5. The mixture was then reacted at 60 °C for 5 h. After washing with water, filtering, and drying under vacuum, modified nano-graphene oxide was obtained.

[0067] Preparation Examples 2-2 to 2-3 are modified graphenes. The difference between them and Preparation Example 2-1 is that the types of raw materials used, the weight of raw materials, and the settings of preparation process parameters are different, as shown in Table 3.

[0068] Table 3. List of raw material types, raw material weights, and preparation process parameters used in the preparation of modified graphene in Preparation Examples 2-1 to 2-3.

[0069]

[0070] Preparation Example 2-4, a modified graphene, differs from Preparation Example 2-1 in that the surfactant used is a silane coupling agent KH570 and a cationic fluorocarbon surfactant in a mass ratio of 1:0.3.

[0071] Preparation Example 2-5, a modified graphene, differs from Preparation Example 2-1 in that the surfactant used is a silane coupling agent KH570 and a cationic fluorocarbon surfactant in a mass ratio of 1:1.5.

[0072] Preparation Example 2-6, a modified graphene, differs from Preparation Example 2-1 in that the cationic fluorocarbon surfactant is replaced in an equal amount with silane coupling agent KH570 in the surfactant.

[0073] Preparation Example 2-7, a modified graphene, differs from Preparation Example 2-1 in that a cationic fluorocarbon surfactant is used to replace the silane coupling agent KH570 in an equal amount in the surfactant.

[0074] Preparation Example 2-8, a modified graphene, differs from Preparation Example 2-1 in that the nonionic surfactant AEO-9 is used in an equal amount to replace the cationic fluorocarbon surfactant.

[0075] Example

[0076] Example 1: An environmentally friendly coating for sandpaper, using the raw materials listed in Table 4, and prepared using the following process:

[0077] Preparation of the first mixed solution: The dispersant was added to water and stirred for 25 minutes at a stirring rate of 800 r / min; then the stearate and anti-adhesion agent were added and stirred for 40 minutes at a stirring rate of 1800 r / min to obtain the first mixed solution.

[0078] Preparation of the second mixed solution: Modified graphene, thickener and stearic acid were added to the organosilicon acrylic polymer and stirred for 60 min at a stirring rate of 800 r / min to obtain the second mixed solution.

[0079] Preparation of environmentally friendly sandpaper coating: The first mixed solution is added to the second mixed solution and stirred for 60 minutes at a stirring rate of 2000 r / min to prepare a slurry. After grinding, the slurry is used to prepare an environmentally friendly sandpaper coating.

[0080] Examples 2-3 are environmentally friendly sandpaper coatings. The difference between them and Example 1 is that the raw material weights, types of raw materials, and process parameters used in the preparation process are different, as shown in Table 4.

[0081] Table 4. List of raw material types, raw material weights, and preparation process parameters used in the preparation process of environmentally friendly sandpaper coatings in Examples 1-3.

[0082]

[0083]

[0084] Examples 4 to 15 are environmentally friendly sandpaper coatings, which differ from Example 1 in that the silicone acrylic polymers used in Examples 1-4 to 1-15 are used sequentially.

[0085] Examples 16 to 20 are environmentally friendly sandpaper coatings, which differ from Example 1 in that the modified graphene is the same as that used in Preparation Examples 2-4 to 2-8.

[0086] Example 21, an environmentally friendly coating for sandpaper, differs from Example 1 in that the organosilicon acrylic polymer used is the same as that used in Preparation Examples 1-10; and the modified graphene used is the same as that used in Preparation Examples 2-2.

[0087] Example 22, an environmentally friendly sandpaper coating, differs from Example 1 in that the anti-adhesion agent is polymethyltriethoxysilane and oxidized polyethylene wax in a mass ratio of 0.5:1.

[0088] Example 23, an environmentally friendly sandpaper coating, differs from Example 1 in that the anti-adhesion agent is polymethyltriethoxysilane and oxidized polyethylene wax in a mass ratio of 0.8:1.

[0089] Example 24, an environmentally friendly sandpaper coating, differs from Example 1 in that the anti-adhesion agent is polymethyltriethoxysilane and oxidized polyethylene wax in a mass ratio of 0.3:1.

[0090] Example 25, an environmentally friendly coating for sandpaper, differs from Example 1 in that it uses polymethyltriethoxysilane to replace oxidized polyethylene wax in an equal amount.

[0091] Example 26, an environmentally friendly coating for sandpaper, differs from Example 1 in that it does not use stearic acid.

[0092] Example 27, an environmentally friendly coating for sandpaper, differs from Example 1 in that it does not use hydroxyethyl cellulose.

[0093] Example 28, an environmentally friendly coating for sandpaper, differs from Example 1 in that it does not use hydroxyethyl cellulose and stearic acid.

[0094] Example 29, an environmentally friendly coating for sandpaper, differs from Example 1 in that it uses polyvinyl alcohol to replace hydroxyethyl cellulose in equal amounts.

[0095] Comparative Example

[0096] Comparative Example 1, an environmentally friendly sandpaper coating, differs from Example 28 in that it does not use an organosilicon acrylic polymer.

[0097] Comparative Example 2, an environmentally friendly coating for sandpaper, differs from Example 28 in that it does not use modified graphene.

[0098] Comparative Example 3, an environmentally friendly sandpaper coating, differs from Example 28 in that it does not use modified graphene and organosilicon acrylic polymer.

[0099] Comparative Example 4, an environmentally friendly coating for sandpaper, differs from Example 28 in that it uses graphene oxide to replace modified graphene in equal amounts.

[0100] Performance testing

[0101] Experiment 1: VOC content

[0102] The VOC content of the environmentally friendly sandpaper coatings of Examples 1-29 and Comparative Examples 1-4 was tested according to B / T 34682-2017. Test results: The VOC content of the environmentally friendly sandpaper coatings of Examples 1-29 and Comparative Examples 1-4 was all below 1 g / L.

[0103] Experiment 2: Grinding amount

[0104] The grinding method used is wet grinding. The sandpaper is soaked in water for 2 hours before grinding. A disc water grinder is used to grind the aluminum rod for 30 minutes each time. The amount of grinding is the change in weight of the aluminum rod before and after grinding. The sandpaper can grind a larger amount in the same amount of time, resulting in higher grinding efficiency.

[0105] Test 3: Anti-clogging performance

[0106] The grinding method used was wet grinding. The sandpaper was soaked in water for 2 hours before grinding. An aluminum rod was ground using a disc wet grinder, and the clogging and detachment of the sandpaper surface were observed after grinding for 100 seconds and 130 seconds respectively.

[0107] Test samples: Sandpaper prepared with the environmentally friendly sandpaper coatings of Examples 1-29 was used as the example samples; sandpaper prepared with the environmentally friendly sandpaper coatings of Comparative Examples 1-4 was used as the comparative example samples.

[0108] Sandpaper preparation method: Apply a primer to a pretreated substrate, then apply sand, heat and dry, then apply a topcoat, and finally apply the environmentally friendly sandpaper coating used in the test sample to prepare the sandpaper. The application rate of the environmentally friendly sandpaper coating is 50 g / m². 2 Cut into shape and set aside.

[0109] Test results: The test results of the grinding amount and anti-clogging properties of the sandpaper with environmentally friendly sandpaper coatings of Examples 1-29 and Comparative Examples 1-4 are shown in Table 5.

[0110] Table 5 lists the evaluation results of the grinding amount and anti-clogging properties of sandpaper using the environmentally friendly sandpaper coatings of Examples 1-29 and Comparative Examples 1-4.

[0111]

[0112]

[0113] As can be seen from Examples 1-29 and Comparative Examples 1-4, and in conjunction with Table 5,

[0114] The sandpaper using the environmentally friendly sandpaper coatings of Examples 1-29 exhibits better grinding capacity and anti-clogging performance than Comparative Examples 1-4, indicating that the use of modified graphene and organosilicon acrylic polymers improves the grinding capacity and anti-clogging performance of the sandpaper prepared using the environmentally friendly sandpaper coatings of this application.

[0115] The reason may be that sandpaper generates a lot of heat during the sanding process. The heat accumulation will reduce the cohesion of the coating on the sandpaper surface and increase its adhesion. During wet sanding, water evaporation can reduce the temperature of the sandpaper surface and improve sanding efficiency. However, during wet sanding, the coating on the sandpaper surface is subjected to water and mechanical force, which causes the coating to peel off too quickly, reducing the service life of the sandpaper.

[0116] The use of modified graphene in environmentally friendly sandpaper coatings has several advantages. First, it improves the thermal conductivity and heat dissipation rate of the coating, reducing heat accumulation on the coating surface. Second, the strong adsorption properties of modified graphene reduce the migration of small molecules, such as anti-blocking agents, dispersants, and stearic acid, from the film layer to the film surface, thereby improving the water resistance and anti-clogging properties of the prepared sandpaper.

[0117] The organosilicon acrylic polymer is prepared by polymerization of halogenated polysiloxanes and monomers containing carbon-carbon double bonds. The halogens in the halogenated polysiloxanes enhance the cohesiveness of the coating and the bonding force with the abrasive. The siloxane groups in the organosilicon acrylic polymer reduce the surface energy of the film, reduce the influence of water on the film and the hydrolysis of halogens, so that the prepared film has low surface energy, water resistance and strong cohesiveness and bonding force with the abrasive.

[0118] The use of organosilicon acrylic polymers in combination with modified graphene improves the thermal conductivity / heat dissipation rate of the film, enhances the water resistance of the film, reduces the rapid migration and shedding of small molecules in the film at high temperatures, and enhances the cohesion of the film and its bonding force with the abrasive. These multiple properties enhance each other, resulting in sandpaper prepared with environmentally friendly sandpaper coatings that has excellent grinding capacity and anti-clogging performance.

[0119] The abrasive yield of sandpaper using the environmentally friendly abrasive coatings of Examples 4-6 is better than that of Examples 1-3 and Example 7, indicating that optimizing the viscosity and weight of the dual-terminated vinyl silicone oil can improve the abrasive yield of sandpaper prepared using environmentally friendly abrasive coatings.

[0120] The reason for this may be that, with other raw material quantities remaining constant, adjusting the viscosity and weight of the dual-end vinyl silicone oil, and adjusting the length and distribution of the silicone oil segments in the molecular chain of the organosilicon acrylic polymer, allows the silicon-oxygen segments to be more evenly distributed in the molecular chain of the organosilicon acrylic polymer. This results in the organosilicon acrylic polymer having both excellent adhesion and hydrophobic properties, leading to a strong bond between the film layer formed by the environmentally friendly sandpaper coating and the abrasive. At the same time, the excellent hydrophobic properties of the organosilicon acrylic polymer improve the water resistance of the sandpaper prepared using the environmentally friendly sandpaper coating, thereby increasing the grinding amount.

[0121] Compared with Example 1, the abrasives with the environmentally friendly abrasive coatings of Examples 8-9 showed poor grinding amount, coating peeling speed, and clogging of the 130s abrasives. This indicates that the organosilicon acrylic polymer formed by the polymerization reaction of halogenated polysiloxane and carbon-carbon double bond monomers in Example 1 has a strong bonding force with the abrasive and also has good hydrophobic properties.

[0122] The reason for this may be that the highly polar halogen elements in the halogenated polysiloxane enhance the bonding force between the polysiloxane and the abrasive, as well as the cohesive force after the coating is formed. The silicon elements are more uniformly segmented in the organosilicon acrylic polymer, which reduces the surface energy of the organosilicon acrylic polymer and improves the poor water resistance of halogenated polysiloxanes. This, in turn, improves the grinding amount and anti-clogging performance of sandpaper prepared using environmentally friendly sandpaper coatings.

[0123] The abrasive amount of sandpaper using the environmentally friendly sandpaper coatings of Examples 10-12 is better than that of Examples 1-3 and Examples 13-15, indicating that the composition of acrylic acid, acrylonitrile and ethyl acrylate with a mass ratio of (0.4-0.6):(0.8-1.5):2: carbon-carbon double bond monomers improves the abrasive amount of sandpaper prepared using the environmentally friendly sandpaper coatings.

[0124] The reasons for this may be as follows: the carboxylic acid groups in methacrylic acid have a strong binding force with cationic emulsifiers, reducing the migration of cationic emulsifiers and improving the problem of poor water resistance caused by the formation of more voids in the film layer of environmentally friendly sandpaper coatings due to emulsifier migration; ethyl acrylate has good adhesion, improving the bonding force between environmentally friendly sandpaper coatings and abrasives, thereby increasing the grinding amount; acrylonitrile has strong polarity, reducing emulsifier migration and enhancing the cohesive force of the film layer; the use of carbon-carbon double bond monomers, such as acrylic acid, acrylonitrile, and ethyl acrylate, in combination with dispersants and modified graphene, improves the grinding amount of sandpaper prepared using environmentally friendly sandpaper coatings.

[0125] However, when the acrylonitrile content is too high, the flexibility decreases; when the acrylic acid content is too low, the compatibility with cationic resins deteriorates; when the acrylonitrile content is too low, the adhesion performance decreases, and the ability to reduce dispersant migration decreases; when the acrylic acid content is too high, the water resistance decreases; thus, the abrasive amount of sandpaper prepared using environmentally friendly sandpaper coatings decreases.

[0126] The sandpaper coated with the environmentally friendly sandpaper coatings of Examples 1-3, 16-17 and 21 exhibits better grinding capacity, coating peeling speed and clogging performance after 130 seconds of sanding than that of Examples 18-20. This indicates that the use of silane coupling agents and cationic fluorocarbon surfactants in the preparation of modified graphene improves the grinding capacity and anti-clogging properties of the sandpaper coated with the environmentally friendly sandpaper coating.

[0127] The reason for this may be that during the preparation of modified graphene, the cationic fluorocarbon surfactant has a strong attraction to the carboxyl groups in the organosilicon acrylic polymer, which reduces the aggregation of modified graphene and improves its dispersion performance; the silane coupling agent enhances the bonding force between modified graphene and organosilicon acrylic polymer; and the combined use of cationic fluorocarbon surfactant and silane coupling agent further improves the grinding amount and anti-clogging properties of sandpaper using environmentally friendly sandpaper coatings.

[0128] The abrasive amount of sandpaper using the environmentally friendly sandpaper coating of Examples 22-23 is better than that of Examples 24-25 and Examples 1-3, indicating that the anti-sticking agent, when used in combination with polymethyltriethoxysilane and oxidized polyethylene wax at a mass ratio of (0.5-0.8):1, improves the abrasive amount of sandpaper using the environmentally friendly sandpaper coating.

[0129] The reason for this may be that, during use, the polymethyltriethoxysilane and oxidized polyethylene wax migrate to the surface of the coating formed by the environmentally friendly sandpaper coating, acting as an isolation and lubricant, reducing the adhesion between processing waste and the environmentally friendly sandpaper coating, and improving sanding efficiency; polymethyltriethoxysilane enhances the hydrophobic properties of the coating formed by the environmentally friendly sandpaper coating, and when combined with organosilicon acrylic polymers, it improves the water resistance of the coating formed by the environmentally friendly sandpaper coating, reducing the damage to the coating formed by wet sanding; oxidized polyethylene wax helps to reduce the surface temperature of the film layer; and the combined use of oxidized polyethylene wax and polymethyltriethoxysilane further increases the grinding amount of the sandpaper using the environmentally friendly sandpaper coating.

[0130] The abrasive yield and coating peeling rate of the sandpaper using the environmentally friendly sandpaper coatings of Examples 1-3 are better than those of Examples 26-29, indicating that the use of hydroxyethyl cellulose and stearic acid in the environmentally friendly sandpaper coatings further improves the abrasive yield and reduces the coating peeling rate of the sandpaper using the environmentally friendly sandpaper coatings.

[0131] The reason for this may be that: low-melting-point stearic acid not only promotes the dispersion of raw materials in environmentally friendly sandpaper coatings, but also melts and absorbs heat during the sanding process, reducing the heat in the sandpaper coating and improving the problem of coating peeling due to decreased cohesion caused by excessively high sandpaper surface temperature; hydroxyethyl cellulose, as a thickener with good adhesion and adsorption effects, when used in combination with modified graphene, reduces the migration speed of small-molecule stearic acid to the film surface at higher temperatures during sanding and the amount of film peeling off, improving the problem of stearic acid migrating too fast and peeling off too quickly during sanding, reducing the heating rate of the film, increasing the sandpaper's grinding amount, and reducing the coating peeling speed.

[0132] This specific embodiment is merely an explanation of this application and is not intended to limit it. After reading this specification, those skilled in the art can make modifications to this embodiment without contributing any inventive step, but such modifications are protected by patent law as long as they fall within the scope of the claims of this application.

Claims

1. An environmentally friendly coating for sandpaper, characterized in that, By weight, it includes 20-50 parts stearate, 3-6 parts anti-sticking agent, 8-20 parts organosilicon acrylic polymer, 3-10 parts modified graphene, 4-6 parts dispersant, and 50-80 parts water. The preparation process of the organosilicon acrylic polymer is as follows: 80-150 parts by weight of double-ended vinyl silicone oil, 30-60 parts by weight of acetone and 180-230 parts by weight of hydrogen halide acetic acid solution are stirred and reacted at 65-75℃ for 3-4 hours, and then the halogenated polysiloxane is prepared by water extraction and heating evaporation. 100 parts by mass of a monomer containing carbon-carbon double bonds, 30-100 parts by mass of a halogenated polysiloxane, 0.1-25 parts by mass of a ligand and 1-300 parts by mass of an organic solvent are mixed, frozen in an ice-salt bath, heated to 50-120°C under nitrogen protection, 0.1-50 parts by mass of a catalyst are added and the mixture is stirred for 10-20 hours to prepare an organosilicon acrylic polymer. The carbon-carbon double bond-containing monomer is a composition of acrylic acid, acrylonitrile, and ethyl acrylate in a mass ratio of (0.4-0.6):(0.8-1.5):2; the ligand is triphenylphosphine or 2,2-bipyridine; and the catalyst is cuprous bromide or ferrous bromide. The preparation process of the modified graphene is as follows: 10-20 parts by weight of nano-graphene oxide, 4-10 parts by weight of surfactant and 8-10 parts by weight of dicyclohexylcarbodiimide were added to 40-60 ml of DMF solvent. After stirring and mixing, ammonia and vitamin C were added in sequence, the pH was adjusted to 6-7, and the reaction was carried out at 60-90℃ for 2-5 h. After washing with water, filtering and drying under vacuum, modified nano-graphene oxide was prepared. The surfactant is a silane coupling agent and a cationic fluorocarbon surfactant in a mass ratio of 1:(0.3-1.5).

2. The environmentally friendly sandpaper coating according to claim 1, characterized in that, The viscosity of the dual-terminated vinyl silicone oil is 300-1500 mPa·s, and the dosage is 40-60 parts by mass.

3. The environmentally friendly sandpaper coating according to claim 1, characterized in that, The stearate is at least one of zinc stearate, calcium stearate, aluminum stearate, and magnesium stearate; the dispersant is at least one of phosphates, sulfonates, and sulfates.

4. The environmentally friendly sandpaper coating according to claim 1, characterized in that, The anti-adhesion agent is a composition of polymethyltriethoxysilane and oxidized polyethylene wax in a mass ratio of (0.3-0.8):

1.

5. The environmentally friendly sandpaper coating according to claim 1, characterized in that, The environmentally friendly sandpaper coating also includes 1-8 parts by weight of stearic acid and 2-4 parts by weight of a thickener; the thickener is hydroxyethyl cellulose.

6. A method for preparing the environmentally friendly sandpaper coating according to any one of claims 1-4, comprising the following preparation steps: After adding the dispersant to water and stirring to mix, add stearate and anti-sticking agent, and stir at high speed for 40-60 minutes to obtain the first mixed solution; The modified graphene was added to the organosilicon acrylic polymer and stirred for 60-80 minutes to prepare a second mixed solution. The first mixed solution is added to the second mixed solution and stirred at high speed for 60-90 minutes to prepare a slurry. After grinding, the slurry is used to prepare an environmentally friendly sandpaper coating.

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