A coating for an aqueous silicon carbide coated abrasive tool and a method of making the same

Abstract

This invention relates to the field of abrasive materials technology and discloses a coating for waterborne silicon carbide coated abrasives, comprising: a solvent, a waterborne epoxy resin, silicon carbide micro powder, a waterborne polyurethane emulsion, a waterborne acrylic emulsion, a waterborne polytetrafluoroethylene emulsion, soluble starch, a waterborne amino curing agent, a waterborne isocyanate curing agent, diethyltetramethylimidazole, a film-forming aid, a defoamer, a dispersant, a substrate wetting agent, and an adhesion promoter; the waterborne polyurethane emulsion is an anionic aliphatic polyester polyurethane dispersion with a high molecular weight and excellent toughness. Adding the waterborne polyurethane emulsion can increase the adhesion of the coating, increase the flexibility of the coating, and prevent the coating from peeling off in whole pieces; the coating can be prepared by workers without spending a lot of time, the operation is simple, waste liquid is generated, and the production efficiency is high; the film-forming aid is a dodecyl alcohol ester, which allows the materials used to be directly dissolved in water.

Description

Technical Field

[0001] This invention relates to the field of abrasive materials technology, specifically to a coating for water-based silicon carbide coated abrasives and its preparation method. Background Technology

[0002] To achieve high transmission rates, fiber optic connectors, one of the most important passive optical components in fiber optic systems, are also evolving towards multimode and multicore designs. MPO stands for Multi-Position Fiber Optic Connector, which can connect multiple fibers simultaneously, providing high-speed, high-density fiber optic connections. MPO fiber optic connectors are widely used in data centers, communication networks, and high-speed fiber optic transmission systems. They provide high-density fiber optic connections, reduce rack space requirements, and improve fiber optic transmission efficiency. MPO connectors also feature low insertion loss and high return loss, ensuring stable optical signal transmission.

[0003] The most important aspect of precisely aligning the two end faces of a fiber optic patch cord is ensuring the alignment of the two fiber axes. This maximizes the coupling of light energy from the transmitting fiber to the receiving fiber and minimizes the impact of the patch cord on the system. Therefore, the end faces of the fiber optic connectors need to be polished to achieve this optical performance. Currently, the common process for MPO ferrule polishing is using a center-pressure polishing machine with a polishing disc, using the following consumables: SC30 → SC16 → SC9 → SC3 → SC1 → white / black cloth + fiber-drawing fluid → black cloth + polishing fluid. With improvements in polishing equipment and consumable quality, the end faces are now required to be free of black spots and scratches.

[0004] Currently, silicon carbide grinding discs commonly used in MPO grinding are solvent-based products, which present several serious problems. Firstly, the resins used in their preparation require strong solvents for dissolution, such as toluene, xylene, methyl ethyl ketone (MEK), and cyclohexanone. Since the raw materials are all organic substances, they are highly toxic. Skin contact with these substances or inhalation of their volatile components can harm the human body, directly impacting the health of the operator. Secondly, the raw materials used in the preparation process, or the waste generated after their use, all require cleaning with organic solvents, producing a large amount of waste liquid. Improper disposal of this waste liquid can cause environmental pollution. Furthermore, organic solvents are generally flammable and explosive, and improper handling can lead to fires. In recent years, environmental pollution has become increasingly serious, and environmental protection issues have received increasing attention. Environmentally friendly products are gradually gaining popularity, and the shift from solvent-based to water-based products has become a trend.

[0005] Patent CN101733688A discloses an aqueous precision polishing film, its preparation method and uses. The abrasive used is silicon carbide, alumina and / or cerium oxide, with a micro-powder size of 0.1~5 micrometers. The abrasive used is too fine, which cannot take into account the first few grinding stages of MPO ferrules. Moreover, the grinding effect of alumina and cerium oxide on MPO ferrules is not good, and the grinding rate is not as fast as that of silicon carbide, which will indirectly affect the efficiency of MPO ferrule manufacturers. The resins used in this patent, such as polyvinyl alcohol, sodium carboxymethyl cellulose, polyacrylamide, and modified starch, have low solubility in water and require prolonged soaking to dissolve effectively. Furthermore, the solid content of the aqueous solution is typically 10%-20%, which makes the coating difficult to dry in continuous production due to the high water content. Polyester, polyurethane, and polyacrylic acid resins are all high-molecular-weight substances that cannot dissolve directly in water, requiring manufacturers to perform hydrophilic modification. Additionally, strong solvents miscible with water are needed to dissolve the resin smoothly, resulting in a solid content of around 50%. Excessive solid content leads to instability in the dissolved adhesive, causing agglomerates. Polyethylene glycol has good water solubility, but it does not bind micropowders and is unsuitable as an adhesive. Moreover, the materials used are organic solvents such as benzene, ketones, and esters, which have a significant environmental impact and pose a considerable hazard to operators. Furthermore, the coating preparation process requires a significant amount of time, generating substantial waste liquid and resulting in low production efficiency. Summary of the Invention

[0006] (a) Technical problems to be solved

[0007] To address the shortcomings of existing technologies, this invention provides a coating for water-based silicon carbide coated abrasives and its preparation method, thereby solving the problems mentioned in the background art, such as the instability of well-dissolved adhesives when the solid content is too high, resulting in agglomerated lumps; and the fact that while polyethylene glycol has good water solubility, it does not have a binding effect on micropowders and is therefore unsuitable as an adhesive.

[0008] (II) Technical Solution

[0009] To achieve the above objectives, the present invention provides the following technical solution: a coating for an aqueous silicon carbide coated abrasive, comprising: a solvent, an aqueous epoxy resin, silicon carbide micro powder, an aqueous polyurethane emulsion, an aqueous acrylic emulsion, an aqueous polytetrafluoroethylene emulsion, soluble starch, an aqueous amino curing agent, an aqueous isocyanate curing agent, diethyltetramethylimidazole, a film-forming aid, a defoamer, a dispersant, a substrate wetting agent, and an adhesion promoter, wherein the solvent comprises 15-30 parts, the silicon carbide micro powder comprises 30-55 parts, and the aqueous epoxy resin comprises 30-55 parts. 12-20 parts of oxygen resin, 0-6 parts of waterborne polyurethane emulsion, 0-6 parts of waterborne acrylic emulsion, 0.1-0.5 parts of waterborne polytetrafluoroethylene emulsion, 0-1 parts of soluble starch, 1-5 parts of waterborne amino curing agent, 1-4 parts of waterborne isocyanate curing agent, 0.3-2 parts of diethyltetramethylimidazolium, 0.5-1.5 parts of film-forming aid, 0.1-0.7 parts of defoamer, 0.5-2.5 parts of dispersant, 0.3-1 part of substrate wetting agent, and 0.3-1 part of adhesion promoter;

[0010] Preferably, the solvent is a mixture of water, isopropanol, and propylene glycol methyl ether in a 5:1:4-5:3:2 ratio. The isopropanol and propylene glycol methyl ether are co-solvents for the aqueous emulsion. Since the viscosity of the slurry required for preparing coated abrasives is low, generally 18s-35s, a large amount of water needs to be added to dilute the slurry and reduce its viscosity. If all water is used to dilute the slurry, due to the characteristics of aqueous emulsions, when the emulsion is diluted to a certain extent, the emulsion system is easily destroyed, leading to demulsification. The compounding of isopropanol and propylene glycol methyl ether can effectively prevent the aqueous emulsion from demulsifying in the system and maintain the stability of the system. The silicon carbide micro powder is green silicon carbide micro powder with a median particle size of 1-30 micrometers. Green silicon carbide contains more than 97% SiC, has good self-sharpening properties, and has high grinding efficiency for MPO inserts.

[0011] Preferably, the waterborne epoxy resin is a bisphenol A type epoxy resin with an epoxy equivalent of 500-2500. The lower the epoxy equivalent, the lower the molecular weight of the epoxy resin and the more brittle the coating is. During the grinding process, the coating is easy to fall off, has poor adhesion, and forms abnormal scratches.

[0012] The higher the epoxy equivalent, the higher the molecular weight of the epoxy resin, and the more flexible the resulting coating. This leads to a decrease in the cutting force during grinding and an increase in the risk of fiber breakage in the MPO ferrule. Choosing a nonionic or anionic emulsion system of waterborne epoxy resin can effectively prevent epoxy resin from peeling off and also improve the cutting force during grinding. The waterborne polyurethane emulsion is an anionic aliphatic polyester polyurethane dispersion with a high molecular weight and good toughness. Adding waterborne polyurethane emulsion can increase the adhesion of the coating, increase the flexibility of the coating, and prevent the coating from peeling off in one piece.

[0013] Preferably, the aqueous acrylic emulsion is one of silicone acrylic emulsion, pure acrylic emulsion, and styrene acrylic emulsion, with a Tg value between 55℃ and 80℃. When using silicon carbide micropowder with a large particle size to prepare coated abrasives, adding aqueous polyurethane emulsion will reduce the grinding force of the coating, leading to edge chipping and fiber breakage. If all aqueous epoxy resin is used, the coating adhesion is poor, and it is easy to peel off in whole pieces, causing abnormal scratches. Adding an appropriate amount of aqueous acrylic emulsion can enhance the coating adhesion while ensuring the grinding force, reducing the phenomenon of abnormal scratches caused by coating peeling off. The aqueous polytetrafluoroethylene emulsion is an aqueous dispersion of polytetrafluoroethylene wax. Polytetrafluoroethylene wax has an extremely low coefficient of friction and plays a lubricating role in this invention. It can effectively adjust the grinding rate of the coating on plastic and glass optical fibers, avoiding the situation where the optical fiber height is too high due to excessive consumption of plastic. At the same time, adding aqueous polytetrafluoroethylene emulsion can effectively prevent the adhesion of the roll material during the heating and curing process after the coated abrasive is dried and rolled up.

[0014] Preferably, the soluble starch is pregelatinized starch, which is soluble in cold water and acts as a thickener. The water-based isocyanate curing agent is a blocked water-based isocyanate curing agent, which can ensure that the isocyanate groups do not react with active hydrogen at room temperature, thus preventing the viscosity of the system from increasing and ensuring the stability of the system.

[0015] Preferably, the film-forming aid is dodecyl alcohol ester, which is a good solubilizer for aqueous emulsions and can promote the overlap between latex particles to form a continuous and uniform film during coating drying. The dispersant is sodium polyacrylate dispersant, which has good dispersion effect and excellent viscosity reduction performance, and can effectively disperse silicon carbide micro powder. The substrate wetting agent is polyether modified polysiloxane, which can quickly reduce the surface tension of the system in the aqueous system, increase the wetting ability of the system substrate, and eliminate the pinhole defects in the coating. The substrate of the aqueous silicon carbide coated abrasive is made of polyethylene terephthalate, and a layer of heat-activated primer is pre-coated on the substrate to enhance its adhesion to the coated abrasive.

[0016] A method for preparing a coating for an aqueous silicon carbide coated abrasive, based on any one of the above-described methods, includes the following steps:

[0017] S1. Add the measured amounts of solvent, silicon carbide micro powder, waterborne epoxy resin, waterborne polyurethane emulsion, waterborne acrylic emulsion, defoamer, and dispersant into a ball mill jar and ball mill for 12-72 hours.

[0018] S2. After ball milling, take a clean container and filter out the material in the ball mill jar. Turn on the high-speed disperser and add the water-based polytetrafluoroethylene emulsion, soluble starch, water-based amino curing agent, water-based isocyanate curing agent, diethyltetramethylimidazole, film-forming aid, defoamer, substrate wetting agent, and adhesion promoter in sequence while stirring at 600-800 rpm. After stirring for 30 minutes, filter the mixture with a filter screen and prepare for coating.

[0019] S3. Apply coating using a precision coating machine, with an oven temperature of 90-140℃ and a dry film thickness of 20-40 micrometers.

[0020] S4. After the coated product is rolled up, it should be cured at 80-100℃ for 8-48 hours.

[0021] S5. After curing, the product is cut into φ127mm round pieces to obtain the final product.

[0022] (III) Beneficial Effects

[0023] Compared with the prior art, the present invention provides a coating for water-based silicon carbide coated abrasives and a method for preparing the same, which has the following beneficial effects:

[0024] 1. The coating of the water-based silicon carbide coated abrasive and its preparation method, wherein the solvent added is a mixture of water, isopropanol and propylene glycol methyl ether in a ratio of 5:1:4-5:3:2. Isopropanol and propylene glycol methyl ether are co-solvents of the water-based emulsion. Since the viscosity of the slurry required for preparing the coated abrasive is low, generally 18s-35s, a large amount of water needs to be added to dilute the slurry and reduce the viscosity. If all the slurry is diluted with water, due to the characteristics of water-based emulsions, when the emulsion is diluted to a certain extent, the emulsion system is easily destroyed, leading to demulsification. The compounding of isopropanol and propylene glycol methyl ether can effectively prevent the water-based emulsion from demulsifying in the system and maintain the stability of the system.

[0025] Waterborne epoxy resins are bisphenol A type epoxy resins with an epoxy equivalent of 500-2500. The lower the epoxy equivalent, the lower the molecular weight of the epoxy resin, and the more brittle the coating becomes. During grinding, the coating is prone to peeling off, resulting in poor adhesion and abnormal scratches. Conversely, the higher the epoxy equivalent and the higher the molecular weight of the epoxy resin, the more flexible the coating becomes. This leads to a decrease in grinding cutting force and an increase in the risk of MPO core fiber breakage. Choosing waterborne epoxy resins with nonionic or anionic emulsion systems can effectively prevent epoxy resin peeling off and also improve the grinding cutting force.

[0026] Waterborne polyurethane emulsion is an anionic aliphatic polyester polyurethane dispersion with a high molecular weight and excellent toughness. Adding waterborne polyurethane emulsion can increase the adhesion of the coating, increase the flexibility of the coating, and prevent the coating from peeling off in one piece.

[0027] The waterborne isocyanate curing agent is a closed-type waterborne isocyanate curing agent, which can ensure that the isocyanate groups do not react with active hydrogen at room temperature and will not increase the viscosity of the system. The substrate of the waterborne silicon carbide coated abrasive uses polyethylene terephthalate with a thickness of 75 micrometers. A layer of heat-activated primer is pre-coated on the substrate to enhance its adhesion to the coated abrasive and ensure the stability of the system. It can effectively prevent the formation of agglomerated lumps in the coating and can achieve more stable bonding.

[0028] 2. The coating of this water-based silicon carbide coated abrasive and its preparation method: the material used to prepare the coating does not use organic solvents such as benzene, ketones, and esters, thus having little impact on the environment and little harm to operators;

[0029] 3. The coating of this water-based silicon carbide coated abrasive and its preparation method only require adding measured amounts of solvent, silicon carbide micro powder, water-based epoxy resin, water-based polyurethane emulsion, water-based acrylic emulsion, defoamer, and dispersant into a ball mill jar for ball milling. Then, water-based polytetrafluoroethylene emulsion, soluble starch, water-based amino curing agent, water-based isocyanate curing agent, diethyltetramethylimidazole, film-forming aid, defoamer, substrate wetting agent, and adhesion promoter are added sequentially and stirred. After drying and cutting, the finished product can be obtained. This allows workers to prepare the coating without spending a lot of time. The operation is simple, waste liquid is generated, and production efficiency is high.

[0030] 4. The coating of this water-based silicon carbide coated abrasive and its preparation method: the soluble starch is pregelatinized starch, which can dissolve in cold water and acts as a thickener; the film-forming aid is dodecyl alcohol ester, which is a good solubilizer for water-based emulsions and can promote the overlap between latex particles to form a continuous and uniform film when the coating dries; the substrate wetting agent is polyether-modified polysiloxane, which rapidly reduces the surface tension of the system in the water-based system, increases the wetting ability of the system substrate, and eliminates the pinhole defects in the coating film, so that the manufacturer does not need to perform hydrophilic modification treatment on the resin, and the materials used can be directly dissolved in water. Detailed Implementation

[0031] The technical solutions in the embodiments of the present invention will be clearly and completely described below. Obviously, the described embodiments are only some embodiments of the present invention, and not all embodiments. Based on the embodiments of the present invention, all other embodiments obtained by those skilled in the art without creative effort are within the scope of protection of the present invention.

[0032] This invention provides a technical solution: a coating for an aqueous silicon carbide-coated abrasive, comprising: a solvent, an aqueous epoxy resin, silicon carbide micro powder, an aqueous polyurethane emulsion, an aqueous acrylic emulsion, an aqueous polytetrafluoroethylene emulsion, soluble starch, an aqueous amino curing agent, an aqueous isocyanate curing agent, diethyltetramethylimidazole, a film-forming aid, a defoamer, a dispersant, a substrate wetting agent, and an adhesion promoter, wherein the solvent is 15-30 parts, the silicon carbide micro powder is 30-55 parts, and the aqueous epoxy resin is 12 parts. -20 parts, waterborne polyurethane emulsion 0-6 parts, waterborne acrylic emulsion 0-6 parts, waterborne polytetrafluoroethylene emulsion 0.1-0.5 parts, soluble starch 0-1 parts, waterborne amino curing agent 1-5 parts, waterborne isocyanate curing agent 1-4 parts, diethyltetramethylimidazolium 0.3-2 parts, film-forming aid 0.5-1.5 parts, defoamer 0.1-0.7 parts, dispersant 0.5-2.5 parts, substrate wetting agent 0.3-1 parts, adhesion promoter 0.3-1 parts;

[0033] Waterborne amino curing agents do not undergo cross-linking reactions with waterborne resins at room temperature, ensuring the stability of the slurry system. Diethyltetramethylimidazole is an excellent curing agent used as an epoxy resin curing agent. It has a low curing temperature and can promote the drying and curing of the waterborne epoxy resin. The defoamer is an organosilicon defoamer with strong defoaming and foam-suppressing abilities, which can effectively reduce the formation of pinholes in the coating due to foaming.

[0034] The solvent is a uniform mixture of water, isopropanol, and propylene glycol methyl ether in a ratio of 5:1:4-5:3:2. Isopropanol and propylene glycol methyl ether are co-solvents for the aqueous emulsion. Since the viscosity of the slurry required for preparing coated abrasives is low, generally 18s-35s, a large amount of water needs to be added to dilute the slurry and reduce its viscosity. However, if all the slurry is diluted with water, due to the characteristics of aqueous emulsions, the emulsion system is easily destroyed when diluted to a certain extent, leading to demulsification. The compounding of isopropanol and propylene glycol methyl ether can effectively prevent the aqueous emulsion from demulsifying within the system and maintain the stability of the system. The silicon carbide micro powder is a green silicon carbide micro powder with a median particle size of 1-30 micrometers. Green silicon carbide contains more than 97% SiC, has good self-sharpening properties, and has high grinding efficiency for MPO inserts.

[0035] Waterborne epoxy resins are bisphenol A type epoxy resins with an epoxy equivalent of 500-2500. The lower the epoxy equivalent, the lower the molecular weight of the epoxy resin, and the more brittle the resulting coating. During grinding, the coating is prone to peeling off, has poor adhesion, and causes abnormal scratches. The higher the epoxy equivalent, the higher the molecular weight of the epoxy resin, and the more flexible the resulting coating. This leads to a decrease in grinding cutting force and an increased risk of MPO core fiber breakage. Choosing waterborne epoxy resins with nonionic or anionic emulsion systems can effectively prevent epoxy resin peeling off and also improve grinding cutting force. Waterborne polyurethane emulsions are anionic aliphatic polyester polyurethane dispersions with a high molecular weight and good toughness. Adding waterborne polyurethane emulsions can increase the adhesion of the coating, increase the flexibility of the coating, and prevent the coating from peeling off in one piece.

[0036] The waterborne acrylic emulsion is one of silicone acrylic emulsion, pure acrylic emulsion, or styrene acrylic emulsion. The Tg value of the emulsion is between 55℃ and 80℃. When using silicon carbide micropowder with a large particle size to prepare coated abrasives, adding waterborne polyurethane emulsion will reduce the grinding force of the coating, leading to edge chipping and fiber breakage. If waterborne epoxy resin is used entirely, the coating adhesion is poor, and it is easy to peel off in whole pieces, causing abnormal scratches. Adding an appropriate amount of waterborne acrylic emulsion can enhance the coating adhesion while ensuring the grinding force, reducing the phenomenon of abnormal scratches caused by coating peeling off. The waterborne polytetrafluoroethylene emulsion is a waterborne dispersion of polytetrafluoroethylene wax. Polytetrafluoroethylene wax has an extremely low coefficient of friction and plays a lubricating role in this invention. It can effectively adjust the grinding rate of the coating on plastic and glass optical fibers, avoiding the situation where the optical fiber height is too high due to excessive consumption of plastic. At the same time, adding waterborne polytetrafluoroethylene emulsion can effectively prevent the adhesion of the roll material during the heating and curing process after the coated abrasive is dried and rolled up.

[0037] The soluble starch is pregelatinized starch, which can dissolve in cold water and acts as a thickener. The water-based isocyanate curing agent is a blocked water-based isocyanate curing agent, which can ensure that the isocyanate groups do not react with active hydrogen at room temperature, thus preventing the viscosity of the system from increasing and ensuring the stability of the system.

[0038] The film-forming aid is dodecyl alcohol ester, which is a good solubilizer for water-based emulsions and can promote the overlap between latex particles to form a continuous and uniform film during coating drying. The dispersant is sodium polyacrylate dispersant, which has good dispersion effect and excellent viscosity reduction performance, and can effectively disperse silicon carbide micro powder. The substrate wetting agent is polyether modified polysiloxane, which can quickly reduce the surface tension of the system in the water-based system, increase the wetting ability of the system substrate, and eliminate the pinhole defects in the coating film. The substrate of the water-based silicon carbide coated abrasive uses polyethylene terephthalate with a thickness of 75 micrometers. A layer of heat-activated primer is pre-coated on the substrate to enhance its adhesion to the coated abrasive.

[0039] A method for preparing a coating for an aqueous silicon carbide coated abrasive, based on any one of the above-mentioned methods, includes the following steps:

[0040] S1. Add the measured amounts of solvent, silicon carbide micro powder, waterborne epoxy resin, waterborne polyurethane emulsion, waterborne acrylic emulsion, defoamer, and dispersant into a ball mill jar and ball mill for 12-72 hours.

[0041] S2. After ball milling, take a clean container and filter out the material in the ball mill jar. Turn on the high-speed disperser and add the water-based polytetrafluoroethylene emulsion, soluble starch, water-based amino curing agent, water-based isocyanate curing agent, diethyltetramethylimidazole, film-forming aid, defoamer, substrate wetting agent, and adhesion promoter in sequence while stirring at 600-800 rpm. After stirring for 30 minutes, filter the mixture with a filter screen and prepare for coating.

[0042] S3. Apply coating using a precision coating machine, with an oven temperature of 90-140℃ and a dry film thickness of 20-40 micrometers.

[0043] S4. After the coated product is rolled up, it should be cured at 80-100℃ for 8-48 hours.

[0044] S5. After curing, the product is cut into φ127mm round pieces to obtain the final product.

[0045] Example 1

[0046] 15 parts solvent, 55 parts 30-micron silicon carbide, 20 parts waterborne epoxy resin, 6 parts waterborne acrylic emulsion, 0.1 parts waterborne polytetrafluoroethylene emulsion, 1 part soluble starch, 5 parts waterborne amino curing agent, 1 part waterborne isocyanate curing agent, 2 parts diethyltetramethylimidazolium, 1.5 parts film-forming aid, 0.1 parts defoamer, 0.5 parts dispersant, 0.3 parts substrate wetting agent, and 1 part adhesion promoter.

[0047] The preparation method is as follows:

[0048] S1. Add the measured amounts of solvent, silicon carbide micro powder, waterborne epoxy resin, waterborne polyurethane emulsion, waterborne acrylic emulsion, defoamer, and dispersant into a ball mill jar and ball mill for 12 hours.

[0049] S2. After ball milling, take a clean container and filter out the material in the ball mill jar. Turn on the high-speed disperser and add the water-based polytetrafluoroethylene emulsion, soluble starch, water-based amino curing agent, water-based isocyanate curing agent, diethyltetramethylimidazole, film-forming aid, defoamer, substrate wetting agent, and adhesion promoter in sequence while stirring at 600-800 rpm. After stirring for 30 minutes, filter the mixture with a filter screen and prepare for coating.

[0050] S3. Apply coating using a precision coating machine, with an oven temperature of 90-140℃, and a dry film thickness of 40 micrometers.

[0051] S4. After the coated product is rolled up, it is cured at 100℃ for 12 hours.

[0052] S5. After curing, the product is cut into φ127mm round pieces to obtain the final product.

[0053] Example 2

[0054] 20 parts solvent, 50 parts 16-micron silicon carbide, 18 parts waterborne epoxy resin, 1 part waterborne polyurethane emulsion, 4 parts waterborne acrylic emulsion, 0.2 parts waterborne polytetrafluoroethylene emulsion, 0.8 parts soluble starch, 4 parts waterborne amino curing agent, 2 parts waterborne isocyanate curing agent, 1.5 parts diethyltetramethylimidazolium, 1.2 parts film-forming aid, 0.2 parts defoamer, 1 part dispersant, 0.5 parts substrate wetting agent, and 0.7 parts adhesion promoter.

[0055] The preparation method is as follows:

[0056] S1. Add the measured amounts of solvent, silicon carbide micro powder, waterborne epoxy resin, waterborne polyurethane emulsion, waterborne acrylic emulsion, defoamer, and dispersant to the ball mill jar and ball mill for 18 hours.

[0057] S2. After ball milling, take a clean container and filter out the material in the ball mill jar. Turn on the high-speed disperser and add the water-based polytetrafluoroethylene emulsion, soluble starch, water-based amino curing agent, water-based isocyanate curing agent, diethyltetramethylimidazole, film-forming aid, defoamer, substrate wetting agent, and adhesion promoter in sequence while stirring at 600-800 rpm. After stirring for 30 minutes, filter the mixture with a filter screen and prepare for coating.

[0058] S3. Apply coating using a precision coating machine, with an oven temperature of 90-140℃, and a dry film thickness of 35 micrometers.

[0059] S4. After the coated product is rolled up, it is cured at 100℃ for 8 hours.

[0060] S5. After curing, the product is cut into φ127mm round pieces to obtain the final product.

[0061] Example 3

[0062] 22 parts solvent, 45 parts 9-micron silicon carbide, 15 parts waterborne epoxy resin, 2 parts waterborne polyurethane emulsion, 3 parts waterborne acrylic emulsion, 0.3 parts waterborne polytetrafluoroethylene emulsion, 0.5 parts soluble starch, 3 parts waterborne amino curing agent, 2.5 parts waterborne isocyanate curing agent, 1 part diethyltetramethylimidazolium, 1 part film-forming aid, 0.4 parts defoamer, 1.2 parts dispersant, 0.7 parts substrate wetting agent, and 0.5 parts adhesion promoter.

[0063] The preparation method is as follows:

[0064] S1. Add the measured amounts of solvent, silicon carbide micro powder, waterborne epoxy resin, waterborne polyurethane emulsion, waterborne acrylic emulsion, defoamer, and dispersant to the ball mill jar and ball mill for 36 hours.

[0065] S2. After ball milling, take a clean container and filter out the material in the ball mill jar. Turn on the high-speed disperser and add the water-based polytetrafluoroethylene emulsion, soluble starch, water-based amino curing agent, water-based isocyanate curing agent, diethyltetramethylimidazole, film-forming aid, defoamer, substrate wetting agent, and adhesion promoter in sequence while stirring at 600-800 rpm. After stirring for 30 minutes, filter the mixture with a filter screen and prepare for coating.

[0066] S3. Apply coating using a precision coating machine, with an oven temperature of 90-140℃, and a dry film thickness of 30 micrometers.

[0067] S4. After the coated product is rolled up, it is cured at 80℃ for 24 hours.

[0068] S5. After curing, the product is cut into φ127mm round pieces to obtain the final product.

[0069] Example 4

[0070] The composition includes: 26 parts solvent, 35 parts 3-micron silicon carbide, 13 parts waterborne epoxy resin, 4 parts waterborne polyurethane emulsion, 1.5 parts waterborne acrylic emulsion, 0.4 parts waterborne polytetrafluoroethylene emulsion, 0.3 parts soluble starch, 2 parts waterborne amino curing agent, 3 parts waterborne isocyanate curing agent, 0.5 parts diethyltetramethylimidazole, 0.8 parts film-forming aid, 0.5 parts defoamer, 2 parts dispersant, 0.8 parts substrate wetting agent, and 0.4 parts adhesion promoter.

[0071] The preparation method is as follows:

[0072] S1. Add the measured amounts of solvent, silicon carbide micro powder, waterborne epoxy resin, waterborne polyurethane emulsion, waterborne acrylic emulsion, defoamer, and dispersant into a ball mill jar and ball mill for 60 hours.

[0073] S2. After ball milling, take a clean container and filter out the material in the ball mill jar. Turn on the high-speed disperser and add the water-based polytetrafluoroethylene emulsion, soluble starch, water-based amino curing agent, water-based isocyanate curing agent, diethyltetramethylimidazole, film-forming aid, defoamer, substrate wetting agent, and adhesion promoter in sequence while stirring at 600-800 rpm. After stirring for 30 minutes, filter the mixture with a filter screen and prepare for coating.

[0074] S3. Apply coating using a precision coating machine, with an oven temperature of 90-140℃, and a dry film thickness of 25 micrometers.

[0075] S4. After the coated product is rolled up, it is cured at 80℃ for 48 hours.

[0076] S5. After curing, the product is cut into φ127mm round pieces to obtain the final product.

[0077] Example 5

[0078] 30 parts solvent, 30 parts 1-micron silicon carbide, 12 parts waterborne epoxy resin, 6 parts waterborne polyurethane emulsion, 0.5 parts waterborne polytetrafluoroethylene emulsion, 1 part waterborne amino curing agent, 4 parts waterborne isocyanate curing agent, 0.3 parts diethyltetramethylimidazole, 0.5 parts film-forming aid, 0.7 parts defoamer, 2.5 parts dispersant, 1 part substrate wetting agent, and 0.3 parts adhesion promoter.

[0079] The preparation method is as follows:

[0080] S1. Add the measured amounts of solvent, silicon carbide micro powder, waterborne epoxy resin, waterborne polyurethane emulsion, waterborne acrylic emulsion, defoamer, and dispersant into a ball mill jar and ball mill for 72 hours.

[0081] S2. After ball milling, take a clean container and filter out the material in the ball mill jar. Turn on the high-speed disperser and add the water-based polytetrafluoroethylene emulsion, soluble starch, water-based amino curing agent, water-based isocyanate curing agent, diethyltetramethylimidazole, film-forming aid, defoamer, substrate wetting agent, and adhesion promoter in sequence while stirring at 600-800 rpm. After stirring for 30 minutes, filter the mixture with a filter screen and prepare for coating.

[0082] S3. Apply coating using a precision coating machine, with an oven temperature of 90-140℃, and a dry film thickness of 20 micrometers.

[0083] S4. After the coated product is rolled up, it is cured at 80℃ for 48 hours.

[0084] S5. After curing, the product is cut into φ127mm round pieces to obtain the final product.

[0085] Examples 6-11

[0086] Examples 6-11 are application examples.

[0087] The Yuxuntong central pressure grinding machine was used, with glass pads selected for grinding. Distilled water was used as the grinding medium for the grinding process, silicon carbide fiber drawing fluid for the fiber drawing process, and cerium oxide polishing fluid for the polishing process. Grinding of 12-core multimode MPO ferrules was performed under the conditions shown in Appendix 1 below. Except for the examples, all consumables used were products of Shaoxing Ziyuan Abrasives Co., Ltd.

[0088] Grinding 1 Example 1 SC30 SC30 SC30 / Example 1 1200 30 60 Grinding 2 / Example 2 SC16 / SC16 Example 2 2400 65 90 Grinding 3 SC9 / Example 3 SC9 / / 3600 100 105 Grinding 4 SC3 SC3 SC3 Example 4 SC3 Example 4 4800 120 120 Grinding 5 SC1 SC1 / SC1 Example 5 / 4800 135 130 Fiber Pulling white cloth white cloth white cloth white cloth white cloth white cloth 5500 150 150 polishing Black skin Black skin Black skin Black skin Black skin Black skin 5500 150 150

[0089] The test results are shown in Appendix Table 2 below. The test results of Examples 6-11 meet the specifications of MPO jumpers.

[0090] Fiber height max / nm 2542 2688 2255 2687 2235 2496 High-speed fiber optic (min / nm) 2460 2520 2004 2492 2105 2256 Maximum core depression / nm 88 79 85 98 86 76

[0091] This apparatus first adds metered amounts of solvent, silicon carbide micro powder, waterborne epoxy resin, waterborne polyurethane emulsion, waterborne acrylic emulsion, defoamer, and dispersant to a ball mill jar and ball mills for 12-72 hours. After ball milling, the material in the ball mill jar is filtered out in a clean container. A high-speed disperser is then turned on, and waterborne polytetrafluoroethylene emulsion, soluble starch, waterborne amino curing agent, waterborne isocyanate curing agent, diethyltetramethylimidazole, film-forming aid, defoamer, substrate wetting agent, and adhesion promoter are added sequentially under stirring at 600-800 rpm. After stirring for 30 minutes, the mixture is filtered through a screen and prepared for coating. Finally, a precision coating machine is used for coating, with an oven temperature of 90-140℃ and a dry film thickness of 20-40 micrometers. After coating, the product is wound up and cured at 80-100℃ for 8-48 hours. The cured product is then cut into φ127mm round pieces to obtain the final product.

[0092] It should be noted that, in this document, relational terms such as "first" and "second" are used only to distinguish one entity or operation from another, and do not necessarily require or imply any such actual relationship or order between these entities or operations. Furthermore, the terms "comprising," "including," or any other variations thereof are intended to cover non-exclusive inclusion, such that a process, method, article, or apparatus that comprises a list of elements includes not only those elements but also other elements not expressly listed, or elements inherent to such process, method, article, or apparatus.

[0093] Although embodiments of the invention have been shown and described, it will be understood by those skilled in the art that various changes, modifications, substitutions and alterations can be made to these embodiments without departing from the principles and spirit of the invention, the scope of which is defined by the appended claims and their equivalents.

Claims

1. A coating for an aqueous silicon carbide-coated abrasive, comprising the following raw materials: The invention comprises a solvent, a waterborne epoxy resin, silicon carbide micro powder, a waterborne polyurethane emulsion, a waterborne acrylic emulsion, a waterborne polytetrafluoroethylene emulsion, soluble starch, a waterborne amino curing agent, a waterborne isocyanate curing agent, diethyltetramethylimidazole, a film-forming aid, a defoamer, a dispersant, a substrate wetting agent, and an adhesion promoter, characterized in that the solvent comprises 15-30 parts, silicon carbide micro powder comprises 30-55 parts, waterborne epoxy resin comprises 12-20 parts, waterborne polyurethane emulsion comprises 0-6 parts, waterborne acrylic emulsion comprises 0-6 parts, waterborne polytetrafluoroethylene emulsion comprises 0.1-0.5 parts, soluble starch comprises 0-1 part, waterborne amino curing agent comprises 1-5 parts, and waterborne isocyanate comprises 1 part. The composition includes 1-4 parts ester curing agent, 0.3-2 parts diethyltetramethylimidazole, 0.5-1.5 parts film-forming aid, 0.1-0.7 parts defoamer, 0.5-2.5 parts dispersant, 0.3-1 parts substrate wetting agent, and 0.3-1 parts adhesion promoter. The solvent is a uniform mixture of water, isopropanol, and propylene glycol methyl ether in a ratio of 5:1:4-5:3:

2. The isopropanol and propylene glycol methyl ether are co-solvents for the aqueous emulsion. The silicon carbide micropowder is green silicon carbide micropowder with a median particle size of 1-30 micrometers and contains more than 97% SiC. The aqueous epoxy resin is a bisphenol A type epoxy resin with an epoxy equivalent of 500-2500. The aqueous polyurethane emulsion is an anionic aliphatic polyester polyurethane dispersion.

2. The coating for an aqueous silicon carbide coated abrasive according to claim 1, characterized in that: The aqueous acrylic emulsion is one of silicone acrylic emulsion, pure acrylic emulsion, and styrene acrylic emulsion, and the aqueous polytetrafluoroethylene emulsion is an aqueous dispersion of polytetrafluoroethylene wax.

3. The coating for an aqueous silicon carbide coated abrasive according to claim 1, characterized in that: The soluble starch is pregelatinized starch, and the aqueous isocyanate curing agent is a closed-type aqueous isocyanate curing agent.

4. The coating of an aqueous silicon carbide coated abrasive according to claim 1, characterized in that: The film-forming aid is dodecyl alcohol ester, the dispersant is sodium polyacrylate dispersant, the substrate wetting agent is polyether modified polysiloxane, and the substrate of the waterborne silicon carbide coated abrasive uses polyethylene terephthalate.

5. A method for preparing a coating for an aqueous silicon carbide coated abrasive, based on the coating for an aqueous silicon carbide coated abrasive according to any one of claims 1 to 4, comprising the following steps: S1. Add the measured amounts of solvent, silicon carbide micro powder, waterborne epoxy resin, waterborne polyurethane emulsion, waterborne acrylic emulsion, defoamer, and dispersant into a ball mill jar and ball mill for 12-72 hours. S2. After ball milling, take a clean container and filter out the material in the ball mill jar. Turn on the high-speed disperser and add the water-based polytetrafluoroethylene emulsion, soluble starch, water-based amino curing agent, water-based isocyanate curing agent, diethyltetramethylimidazole, film-forming aid, defoamer, substrate wetting agent, and adhesion promoter in sequence while stirring at 600-800 rpm. After stirring for 30 minutes, filter the mixture with a filter screen and prepare for coating. S3. Apply coating using a precision coating machine, with an oven temperature of 90-140℃ and a dry film thickness of 20-40 micrometers. S4. After the coated product is rolled up, it should be cured at 80-100℃ for 8-48 hours. S5. After curing, the product is cut into φ127mm round pieces to obtain the final product.