A foam-based abrasive block and a method of making the same

Abstract

The present application relates to abrasive tool manufacturing technical field, specifically to a kind of abrasive block based on foam substrate and preparation method thereof, including the following steps: S1, provide foam substrate, and on its polishing working surface, organic-inorganic hybrid interface polarity modifier is coated, after drying treatment, again, the polishing working surface is carried out corona treatment;S2, on the polishing working surface after corona treatment, coat primer, form primer layer;S3, implant abrasive on primer layer, form abrasive layer;S4, after abrasive layer is implanted, substrate is carried out initial solidification treatment;S5, on the surface of abrasive layer after initial solidification, recoat, form recoat layer;S6, after recoating, substrate is carried out main solidification treatment, again, aftertreatment, abrasive block is obtained.The present application can greatly extend the corona shelf life by coating organic-inorganic hybrid interface polarity modifier first, then corona treatment, ensure that interface is always in high activity state when subsequent primer coating, significantly improve the adhesive strength of abrasive layer and foam substrate.

Description

Technical Field

[0001] This invention relates to the field of abrasive manufacturing technology, specifically to an abrasive block based on a foam substrate and its preparation method. Background Technology

[0002] Elastic abrasive blocks (sponge blocks) possess excellent elasticity and flexibility, enabling them to adapt to workpiece surfaces with varying curvatures or irregular shapes. They are widely used in woodworking for deburring, automotive paint repair, hardware polishing, and wall sanding. Existing manufacturing processes for sponge blocks primarily involve two methods: "re-lamination" and "coating." The "re-lamination" method involves numerous steps, and the cured adhesive layer significantly increases localized hardness, causing the sponge block to lose its original high flexibility and excellent surface adhesion. The "coating" method increases material costs, and the complex hot-pressing film process can easily lead to sponge deformation.

[0003] To simplify the process and maintain excellent surface adhesion, directly applying adhesive and sand to the surface of the foam substrate is the ideal solution. However, the foam substrate surface is porous and has extremely low surface energy. Although ordinary physical corona treatment can increase surface tension in a short time, its activation effect on the inner walls of the porous micropores is poor, and there is a serious "corona aging regression" phenomenon, resulting in insufficient interlayer bonding between the primer and the foam substrate. Under actual high-load grinding shear forces, the abrasive layer is prone to peeling off in sheets or the bottom substrate may tear. In addition, water-based environmentally friendly resin adhesives, due to their high molecular chain flexibility and limited cohesive strength, are prone to softening and sand shedding during frictional heat if deep interpenetrating network cross-curing is not performed. Summary of the Invention

[0004] In order to overcome the shortcomings of the prior art, the purpose of this invention is to provide a grinding block based on a foam substrate and its preparation method, which can at least solve some of the defects in the prior art.

[0005] To achieve the above objectives, the technical solution of the present invention is a method for preparing a grinding block based on a foam substrate, comprising the following steps:

[0006] S1. Provide a foam substrate and coat an organic-inorganic hybrid interface polar modifier on its grinding surface. After drying, the grinding surface is then subjected to corona treatment.

[0007] S2. Apply a primer to the polishing surface after corona treatment to form a primer layer;

[0008] S3. Abrasives are implanted into the base adhesive layer to form an abrasive layer;

[0009] S4. Perform initial curing treatment on the substrate after the abrasive layer is implanted;

[0010] S5. Apply adhesive to the surface of the abrasive layer after initial curing to form an adhesive layer;

[0011] S6. The substrate after coating with adhesive is subjected to primary curing treatment, followed by post-treatment, to obtain the grinding block.

[0012] As one embodiment, in step S1, the organic-inorganic hybrid interface polar modifier includes the following components by mass percentage: 0.5%~2.0% terminal amino hyperbranched polymer, 0.2%~1.0% silane-functionalized nano silica sol, and the balance being deionized water.

[0013] As one embodiment, the amino-terminated hyperbranched polymer is at least one of amino-terminated hyperbranched polyamide-amine, amino-terminated hyperbranched polyethyleneimine, amino-terminated hyperbranched polyurethane, and amino-terminated hyperbranched polyether; the silane-functionalized nano-silica sol is an aminosilane or epoxysilane-modified nano-silica hydrosol with an average particle size of 15-30 nm; the aminosilane is at least one of γ-aminopropyltriethoxysilane, γ-aminopropyltrimethoxysilane, and N-(β-aminoethyl)-γ-aminopropyltrimethoxysilane, and the epoxysilane is γ-(2,3-epoxypropoxy)propyltrimethoxysilane.

[0014] As one implementation method, in step S1, the coating amount of the organic-inorganic hybrid interface polar modifier is 5~15 g / m², the drying treatment is baking at 40℃~50℃ for 5~10 minutes, and the corona treatment conditions are: processing power of 1.0~3.0 kW and conveying line speed of 5~20 m / min.

[0015] As one embodiment, in step S1, the foam substrate is one of polyurethane foam material, ethylene-vinyl acetate copolymer foam material or polyethylene foam material, and its density is 30~80 kg / m³.

[0016] As one embodiment, in step S2, the primer includes an aqueous resin matrix, a primary crosslinking agent, and a secondary crosslinking agent. The amount of the primary crosslinking agent is 1% to 3% of the mass of the aqueous resin matrix, and the amount of the secondary crosslinking agent is 0.5% to 1.5% of the mass of the aqueous resin matrix.

[0017] As one embodiment, the waterborne resin matrix is ​​a waterborne polyurethane adhesive or a modified waterborne epoxy resin adhesive, the main crosslinking agent is at least one of a polyisocyanate crosslinking agent, a blocked polyisocyanate crosslinking agent, and a waterborne amino resin crosslinking agent, and the auxiliary crosslinking agent is at least one of a polyaziridine crosslinking agent, a polycarbodiimide crosslinking agent, a waterborne oxazoline crosslinking agent, a waterborne epoxy crosslinking agent, and a waterborne silane crosslinking agent.

[0018] As one implementation method, in step S4, the initial curing treatment temperature is 60℃~85℃ and the time is 20~40 minutes.

[0019] As one of the implementation methods, in step S6, the main curing treatment adopts a stepped curing process, specifically: first, keep at 60℃~70℃ for 0.5~1 hour, and then raise the temperature to 90℃~110℃ and keep at 90℃~110℃ for 2~3 hours.

[0020] The present invention also provides a grinding block based on a foam substrate prepared by any of the above preparation methods.

[0021] Compared with the prior art, the present invention has the following beneficial effects:

[0022] (1) In this invention, an organic-inorganic hybrid interface polar modifier is first coated on the grinding surface of the foam substrate, so that it fully wets the grinding surface and penetrates into the micropore wall inside the foam substrate. Then, corona treatment is performed. The high-energy particles generated by the corona not only bombard the foam substrate itself, but also induce the organic-inorganic hybrid interface polar modifier to generate highly concentrated active free radicals in situ, and form an organic-inorganic hybrid self-locking structure with micro-nano roughness. This greatly prolongs the surface tension retention period of the foam substrate, providing extremely dense bonding sites for the spread and chemical grafting of the primer, and significantly improving the bonding strength between the abrasive layer and the foam substrate.

[0023] (2) The base adhesive of the present invention uses a water-based resin matrix and introduces a dual crosslinking system composed of a main crosslinking agent and a secondary crosslinking agent. During the curing process, the main crosslinking agent and the secondary crosslinking agent react with the water-based resin matrix in a dual crosslinking reaction to form a three-dimensional interpenetrating dual crosslinking enhanced polymer network. It covalently bonds with the hyperbranched polymer residual amino groups and active free radicals such as polar functional groups of the foam substrate inward and wraps the abrasive in a high-density network outward, thereby significantly improving the cohesive strength and interfacial shear strength of the base adhesive layer, so that the abrasive block can maintain zero sand shedding and no tearing even under the harsh working conditions of high-intensity friction and heat generation.

[0024] (3) The grinding block of the present invention retains the original high flexibility and curved surface fit of the sponge substrate, and through the high strength bonding between the base adhesive layer and the foam substrate, it has excellent wear resistance and temperature resistance, and is not easy to lose sand due to heat during grinding.

[0025] (4) The base adhesive and the top adhesive of the present invention are both made of environmentally friendly water-based resin, which is green and environmentally friendly, and eliminates the traditional complicated application or lamination process, resulting in high production efficiency and low cost. Detailed Implementation

[0026] 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.

[0027] This invention provides a method for preparing a grinding block based on a foam substrate, comprising the following steps:

[0028] S1. Provide a foam substrate and coat an organic-inorganic hybrid interface polar modifier on its grinding surface. After drying, the grinding surface is then subjected to corona treatment.

[0029] S2. Apply a primer to the polishing surface after corona treatment to form a primer layer;

[0030] S3. Abrasives are implanted into the base adhesive layer to form an abrasive layer;

[0031] S4. Perform initial curing treatment on the substrate after the abrasive layer is implanted;

[0032] S5. Apply adhesive to the surface of the abrasive layer after initial curing to form an adhesive layer;

[0033] S6. The substrate after coating with adhesive is subjected to primary curing treatment, followed by post-treatment, to obtain the grinding block.

[0034] In this embodiment, an organic-inorganic hybrid interface polar modifier is first coated on the sanding surface of the foam substrate, allowing it to fully wet the sanding surface and penetrate into the micropore walls inside the foam substrate. Then, corona treatment is performed. The high-energy particles generated by the corona treatment not only bombard the foam substrate itself, but also induce the organic-inorganic hybrid interface polar modifier to generate highly concentrated active free radicals in situ, forming a micro-nano rough organic-inorganic hybrid self-locking structure. This significantly extends the corona treatment time, ensuring that the interface remains in a highly active state during the subsequent primer coating, and significantly improving the adhesion strength between the abrasive layer and the foam substrate.

[0035] In some embodiments, in step S1, the organic-inorganic hybrid interface polar modifier comprises the following components by mass percentage: 0.5%~2.0% terminal amino hyperbranched polymer, 0.2%~1.0% silane-functionalized nano-silica sol, and the balance being deionized water. In this embodiment, the organic-inorganic hybrid interface polar modifier employs a composite system of terminal amino hyperbranched polymer and silane-functionalized nano-silica sol. The hyperbranched polymer, with its abundant terminal active amino groups and excellent wetting and penetrating properties, can penetrate deep into the inner surface of the foam substrate's pores. Under the action of the hyperbranched polymer, the silane-functionalized nano-silica sol is uniformly distributed at nanoscale on the inner surface of the pores. In subsequent corona activation treatment, it can generate highly dense active sites on the surface and inside the foam substrate, forming a micro-nano rough organic-inorganic hybrid self-locking structure.

[0036] Preferably, the amino-terminated hyperbranched polymer is at least one of amino-terminated hyperbranched polyamide-amine, amino-terminated hyperbranched polyethyleneimine, amino-terminated hyperbranched polyurethane, and amino-terminated hyperbranched polyether; the silane-functionalized nano-silica sol is an aminosilane or epoxysilane-modified nano-silica hydrosol with an average particle size of 15-30 nm; the aminosilane is at least one of γ-aminopropyltriethoxysilane, γ-aminopropyltrimethoxysilane, and N-(β-aminoethyl)-γ-aminopropyltrimethoxysilane, and the epoxysilane is γ-(2,3-epoxypropoxy)propyltrimethoxysilane. The amino-terminated hyperbranched polyamide-amine exhibits excellent wetting and penetration properties and multifunctional reactivity; the aminosilane or epoxysilane-modified nano-silica hydrosol has good permeability and dispersion stability, and can form a network structure with the amino-terminated hyperbranched polyamide-amine.

[0037] Furthermore, in step S1, the coating amount of the organic-inorganic hybrid interfacial polar modifier is 5~15 g / m², and the drying treatment is baking at 40℃~50℃ for 5~10 minutes; the corona treatment conditions are: processing power of 1.0~3.0 kW and conveyor line speed of 5~20 m / min. The low-temperature, short-time drying process effectively removes moisture while avoiding damage to the structure from high temperatures. By controlling the processing power and conveyor line speed of the corona treatment, the sanding surface of the foam substrate can be fully and uniformly modified, achieving a surface tension of 35~50 dyn / cm, thereby ensuring the interfacial bonding strength with the primer.

[0038] Furthermore, in step S1, the foam substrate is one of polyurethane foam material, ethylene-vinyl acetate copolymer foam material, or polyethylene foam material, with a density of 30~80 kg / m³, which can provide sufficient mechanical support and resilience.

[0039] In some embodiments, in step S2, the primer includes an aqueous resin matrix, a primary crosslinking agent, and a secondary crosslinking agent. The amount of the primary crosslinking agent is 1% to 3% of the mass of the aqueous resin matrix, and the amount of the secondary crosslinking agent is 0.5% to 1.5% of the mass of the aqueous resin matrix. In this embodiment, the primer uses an aqueous resin matrix and introduces a dual crosslinking system composed of a primary crosslinking agent and a secondary crosslinking agent. During the curing process, the primary and secondary crosslinking agents react with the aqueous resin matrix to form a unique microscopic interpenetrating polymer network (IPN). This IPN covalently bonds internally with the hyperbranched polymer residual amino groups and polar functional groups of the foam substrate, and externally encapsulates the abrasive in a high-density network, thereby improving the cohesive strength and interfacial shear strength of the primer layer. This ensures that the abrasive block maintains zero shedding and no tearing even under harsh conditions of high-intensity frictional heat generation. The coating amount of the primer is 50 to 120 g / m².

[0040] Preferably, the waterborne resin matrix is ​​a waterborne polyurethane adhesive or a modified waterborne epoxy resin adhesive, the main crosslinking agent is at least one of a polyisocyanate crosslinking agent, a blocked polyisocyanate crosslinking agent, and a waterborne amino resin crosslinking agent, and the auxiliary crosslinking agent is at least one of a polyaziridine crosslinking agent, a polycarbodiimide crosslinking agent, a waterborne oxazoline crosslinking agent, a waterborne epoxy crosslinking agent, and a waterborne silane crosslinking agent. The -NCO groups in polyisocyanate crosslinking agents and blocked polyisocyanate crosslinking agents, as well as the -NH2 groups in waterborne amino resin crosslinking agents, can react with the hydroxyl / carboxyl groups in waterborne polyurethane adhesives / modified waterborne epoxy resins and the surface layer of foam substrates. Polyaziridinium crosslinking agents, polycarbodiimide crosslinking agents, waterborne oxazoline crosslinking agents, waterborne epoxy crosslinking agents, and waterborne silane crosslinking agents begin to crosslink efficiently with the carboxyl groups in waterborne polyurethane adhesives / modified waterborne epoxy resins and the residual amino groups in the hyperbranched polymers on the surface layer of foam substrates at relatively low temperatures. This forms a microscopic interpenetrating polymer network at the interface between the primer and the foam substrate, resulting in a qualitative leap in both the cohesive strength of the adhesive layer and the interfacial adhesive shear strength.

[0041] Furthermore, in step S3, the abrasive is at least one of silicon carbide, brown fused alumina, white fused alumina, or ceramic abrasive, and the particle size of the abrasive is P120 to P800 mesh; specifically, an electrostatic sand-planting process can be used to implant the abrasive onto the base layer. The process parameters of the electrostatic sand-planting process are: electrostatic voltage of 20 to 40 kV, and relative humidity of the sand-planting environment controlled at 45% to 65%.

[0042] Furthermore, in step S4, the initial curing temperature is 60℃~85℃, and the time is 20~40 minutes. This initial curing process dehydrates the base adhesive layer, placing it in a semi-cured state and fixing the abrasive root.

[0043] Furthermore, in step S5, the adhesive is a water-based acrylic resin solution or a water-based phenolic resin solution, and the coating amount is 30~80 g / m².

[0044] Furthermore, in step S6, the primary curing treatment employs a stepped curing process, specifically: first, maintaining the temperature at 60℃~70℃ for 0.5~1 hour, then raising the temperature to 90℃~110℃ and maintaining it for 2~3 hours. The primary curing uses a stepped heating method, first allowing residual moisture to evaporate at a low temperature and forming a preliminary cross-linking network, then raising the temperature to allow the cross-linking reaction to proceed fully, forming a three-dimensional network structure, thereby ensuring the adhesive layer's bonding strength.

[0045] This embodiment also provides a grinding block based on a foam substrate prepared by any of the above preparation methods.

[0046] The preparation method of the present invention will be further explained below with reference to specific embodiments and comparative examples.

[0047] Example 1

[0048] This embodiment provides a method for preparing a grinding block based on a foam substrate, including the following steps:

[0049] S1. Select polyurethane (PU) foam material with a density of 50 kg / m³ and cut it into shape to obtain a foam substrate with a sanding working surface and a handheld surface; first, uniformly spray or roll-coat an organic-inorganic hybrid interface polar modifier on the sanding working surface of the foam substrate, with a coating amount of 8 g / m²; then bake at 45℃ for 8 minutes, followed by treatment with a high-frequency corona machine with a processing power of 1.5 kW and a conveyor line speed of 10 m / min. After testing, the surface tension of the sanding working surface reached 45 dyn / cm; wherein, the organic-inorganic hybrid interface polar modifier includes the following components by mass percentage: 1.0% of terminal amino hyperbranched polyamide-amine, 0.5% of γ-aminopropyltriethoxysilane modified nano silica hydrosol, and 98.5 wt% of deionized water;

[0050] S2. Apply a primer evenly to the corona-treated grinding surface to form a primer layer. The primer includes a water-based polyurethane adhesive, a polyisocyanate crosslinking agent, and a polyaziridine crosslinking agent. The amount of the polyisocyanate crosslinking agent is 2.0% of the mass of the water-based polyurethane adhesive, and the amount of the polyaziridine crosslinking agent is 1.0% of the mass of the water-based polyurethane adhesive. The application amount of the primer is 80 g / m².

[0051] S3. Using an electrostatic sand planting machine, with the electrostatic voltage set at 30 kV and the ambient humidity at 50%, P400 mesh silicon carbide abrasive is implanted into the base adhesive layer to form an abrasive layer.

[0052] S4. After the abrasive layer is implanted, the substrate is sent into a 70°C drying oven for initial curing for 30 minutes to make the base adhesive layer semi-cured and fix the root of the abrasive.

[0053] S5. After initial curing, a water-based acrylic resin solution is uniformly sprayed onto the surface of the abrasive layer to form a coating layer with a coating amount of 40 g / m².

[0054] S6. The coated substrate is sent into the main drying tunnel and first kept at 60°C for 1 hour to dehydrate. Then, the temperature is slowly raised to 100°C and kept at 100°C for 2.5 hours for main cross-linking and curing. After cooling and trimming, the grinding block is obtained.

[0055] Example 2

[0056] This embodiment provides a method for preparing a grinding block based on a foam substrate, including the following steps:

[0057] S1. Ethylene-vinyl acetate copolymer (EVA) foam material with a density of 30 kg / m³ was selected and cut into shape to obtain a foam substrate with a sanding surface and a handheld surface. An organic-inorganic hybrid interface polar modifier was uniformly sprayed onto the sanding surface of the foam substrate at a coating amount of 5 g / m². Then, it was baked at 40℃ for 10 minutes, followed by treatment using a high-frequency corona discharge machine with a processing power of 1.5 kW and a conveyor line speed of 10 m / min. The surface tension of the sanding surface was tested to reach 42 dyn / cm. The organic-inorganic hybrid interface polar modifier comprised the following components by mass percentage: 2.0% terminal amino-terminated hyperbranched polyamide-amine, 1.0% γ-aminopropyltriethoxysilane-modified nano-silica hydrosol, and 97% deionized water.

[0058] S2. Apply a primer evenly to the corona-treated grinding surface to form a primer layer. The primer includes polyurethane-modified waterborne epoxy resin, polyisocyanate crosslinking agent, and polyaziridine crosslinking agent. The amount of polyisocyanate crosslinking agent is 1.0% of the mass of polyurethane-modified waterborne epoxy resin, and the amount of polyaziridine crosslinking agent is 1.0% of the mass of polyurethane-modified waterborne epoxy resin. The application amount of the primer is 120 g / m².

[0059] S3. Using an electrostatic sand planting machine, with the electrostatic voltage set at 30 kV and the ambient humidity at 50%, P120 mesh brown fused alumina abrasive is implanted into the base adhesive layer to form an abrasive layer.

[0060] S4. After the abrasive layer is implanted, the substrate is sent into a 60°C drying oven for initial curing for 40 minutes to make the base adhesive layer semi-cured and fix the root of the abrasive.

[0061] S5. After initial curing, a water-based acrylic resin solution is uniformly sprayed onto the surface of the abrasive layer to form a coating layer with a coating amount of 50 g / m².

[0062] S6. The coated substrate is sent into the main drying tunnel and first kept at 70°C for 0.5 hours to dehydrate. Then, the temperature is slowly raised to 100°C and kept at 100°C for 2 hours for main cross-linking and curing. After cooling and trimming, the grinding block is obtained.

[0063] Example 3

[0064] This embodiment provides a method for preparing a grinding block based on a foam substrate, including the following steps:

[0065] S1. Select polyethylene (PE) foam material with a density of 80 kg / m³ and cut it into shape to obtain a foam substrate with a grinding surface and a handheld surface. First, uniformly spray an organic-inorganic hybrid interface polar modifier onto the grinding surface of the foam substrate, with a coating amount of 15 g / m². Then, bake at 50℃ for 5 minutes, followed by treatment using a high-frequency corona machine with a processing power of 2.0 kW and a conveyor line speed of 15 m / min. The surface tension of the grinding surface was tested to reach 48 dyn / cm. The organic-inorganic hybrid interface polar modifier includes the following components by mass percentage: 0.5% terminal amino hyperbranched polyethyleneimine, 0.8% γ-aminopropyltriethoxysilane modified nano silica hydrosol, and 98.7% deionized water.

[0066] S2. Apply a primer evenly to the corona-treated grinding surface to form a primer layer. The primer includes a water-based polyurethane adhesive, a polyisocyanate crosslinking agent, and a polyaziridine crosslinking agent. The amount of the polyisocyanate crosslinking agent is 3.0% of the mass of the water-based polyurethane adhesive, and the amount of the polyaziridine crosslinking agent is 1.5% of the mass of the water-based polyurethane adhesive. The application amount of the primer is 80 g / m².

[0067] S3. Using an electrostatic sand planting machine, with the electrostatic voltage set at 30 kV and the ambient humidity at 45%, P800-mesh white corundum abrasive is implanted into the base adhesive layer to form an abrasive layer.

[0068] S4. After the abrasive layer is implanted, the substrate is sent into a 70°C drying oven for initial curing for 30 minutes to make the base adhesive layer semi-cured and fix the root of the abrasive.

[0069] S5. After initial curing, water-based phenolic resin solution is uniformly sprayed onto the surface of the abrasive layer to form a coating layer with a coating amount of 30 g / m².

[0070] S6. The coated substrate is sent into the main drying tunnel, first kept at 65°C for 1 hour to dehydrate, then slowly heated to 110°C and kept at 110°C for 2 hours for main cross-linking and curing, and then cooled and trimmed to obtain the grinding block.

[0071] Example 4

[0072] This embodiment provides a method for preparing a grinding block based on a foam substrate, including the following steps:

[0073] S1. Polyurethane (PU) foam material with a density of 50 kg / m³ is selected and cut into shape to obtain a foam substrate with a sanding working surface and a handheld surface. An organic-inorganic hybrid interface polar modifier is uniformly sprayed onto the sanding working surface of the foam substrate at a coating amount of 8 g / m². Then, it is baked at 45℃ for 9 minutes, followed by treatment using a high-frequency corona treatment machine with a processing power of 2.5 kW and a conveyor line speed of 20 m / min. The surface tension of the sanding working surface is tested to reach 50 dyn / cm. The organic-inorganic hybrid interface polar modifier comprises the following components by mass percentage: 1.0% terminal amino-terminated hyperbranched polyamide-amine, 1.0% γ-aminopropyltriethoxysilane-modified nano-silica hydrosol, and 98% deionized water.

[0074] S2. Apply a primer evenly to the corona-treated grinding surface to form a primer layer. The primer includes a water-based polyurethane adhesive, a polyisocyanate crosslinking agent, and a polycarbodiimide crosslinking agent. The amount of the polyisocyanate crosslinking agent is 1.5% of the mass of the water-based polyurethane adhesive, and the amount of the polycarbodiimide crosslinking agent is 0.5% of the mass of the water-based polyurethane adhesive. The application rate of the primer is 50 g / m².

[0075] S3. Using an electrostatic sand planting machine, with the electrostatic voltage set at 30 kV and the ambient humidity at 65%, P240 mesh ceramic abrasive is implanted into the base adhesive layer to form an abrasive layer.

[0076] S4. After the abrasive layer is implanted, the substrate is sent into an 85°C drying tunnel for initial curing for 20 minutes to make the base adhesive layer semi-cured and fix the root of the abrasive.

[0077] S5. After initial curing, a water-based acrylic resin solution is uniformly sprayed onto the surface of the abrasive layer to form a coating layer with a coating amount of 45 g / m².

[0078] S6. The coated substrate is sent into the main drying tunnel and first kept at 70°C for 0.5 hours to dehydrate. Then, the temperature is slowly raised to 90°C and kept at 90°C for 3 hours for main cross-linking and curing. After cooling and trimming, the grinding block is obtained.

[0079] Comparative Example 1

[0080] The remaining steps and materials of the preparation method of the grinding block based on the foam substrate are completely identical to those in Example 1, except that: in step S1, the organic-inorganic hybrid interface polar modifier is not sprayed, and the grinding surface of the foam substrate is directly corona treated by a high-frequency corona machine. The surface tension of the foam substrate is about 28 dyn / cm after testing.

[0081] Comparative Example 2

[0082] The remaining steps and materials of the preparation method of the grinding block based on the foam substrate are completely identical to those in Example 1, except that: in step S2, no polyisocyanate crosslinking agent and polyaziridine crosslinking agent are added to the primer.

[0083] Comparative Example 3

[0084] The remaining steps and materials of the method for preparing the grinding block based on the foam substrate are completely identical to those in Example 1, except that in step S1, the organic-inorganic hybrid interface polar modifier is replaced with an aqueous solution of a conventional silane coupling agent (γ-aminopropyltriethoxysilane, KH-550) of the same concentration.

[0085] Comparative Example 4

[0086] The remaining steps and materials of the preparation method of the grinding block based on the foam substrate are completely identical to those in Example 1, except that in step S2, only 2.0% of a polyisocyanate crosslinking agent is added to the primer, and no polyaziridine co-crosslinking agent is added.

[0087] The abrasion life of the foam-based grinding blocks prepared in Examples 1-4 and Comparative Examples 1-4 was tested. A reciprocating linear friction testing machine was used, and under a counterweight pressure of 2.0 kg, the grinding working surface of the grinding block was brought into contact with the surface of a standard steel plate for testing. The number of reciprocating friction cycles was recorded when the surface of the grinding block showed "abrasion loss area greater than 5%" or "tears in the underlying foam substrate." The test results are shown in Table 1.

[0088] Table 1. Results of abrasion resistance life test

[0089]

[0090] As can be clearly seen from Table 1, the abrasive block based on foam substrate prepared by the present invention has excellent friction resistance life, reaching more than 6300 cycles, and there is no problem of sand shedding or peeling when it fails, and the structure has good integrity.

[0091] Compared to Comparative Example 1, which underwent corona treatment without pretreatment of the grinding surface using an organic-inorganic hybrid interface polar modifier, Example 1, after applying an organic-inorganic hybrid interface polar modifier composed of terminal amino hyperbranched polymers and silane-functionalized nano-silica sol to the grinding surface and then undergoing corona treatment, and upgrading to a double crosslinking system, saw its friction life increase dramatically from 480 cycles to 7100 cycles. Furthermore, the failure behavior changed from "loss of underlying bonding strength" to "normal abrasive wear," indicating that the addition of the organic-inorganic hybrid interface polar modifier enabled the interfacial bonding strength to completely surpass the cohesive strength of the sponge substrate itself. Comparative Example 3, after coating with a conventional monomeric silane coupling agent (KH-550) and then undergoing corona treatment, lacked the highly dense spatial network of terminal active groups in the hyperbranched polymer, making it unable to form a micro-nano-scale organic-inorganic hybrid self-locking structure under corona bombardment. Its friction life (2400 cycles) was far inferior to that of Example 1 (7100 cycles).

[0092] The primer in Comparative Example 2 did not contain a dual crosslinking system and relied solely on the evaporation and drying of the water-based resin matrix to form a film. Due to the lack of a three-dimensional chemical crosslinking network, the cohesive force of the resin coating was extremely low, and its heat and water resistance were poor. Under actual grinding stress, this uncrosslinked primer could not provide sufficient abrasive holding force, resulting in large-area sand shedding and sand dropping of the abrasive block in a very short time. The primer in Comparative Example 4 added a single crosslinking agent, which could improve the resin film-forming properties and wear life to a certain extent, but the degree of crosslinking reaction was limited, the crosslinking network structure was simple, the performance improvement was limited, and the failure was manifested as local sand shedding. Compared with Comparative Examples 2 and 4, the primer in Example 1 used a dual crosslinking system, which could induce a violent microscopic interpenetrating network reaction and covalent bonding at the interface, greatly improving sand shedding and substrate tearing.

[0093] The above description is only a preferred embodiment of the present invention and is not intended to limit the present invention. Any modifications, equivalent substitutions, improvements, etc., made within the spirit and principles of the present invention should be included within the protection scope of the present invention.

Claims

1. A method for preparing a grinding block based on a foam substrate, characterized in that, Includes the following steps: S1. Provide a foam substrate and coat an organic-inorganic hybrid interface polar modifier on its grinding surface. After drying, the grinding surface is then subjected to corona treatment. S2. Apply a primer to the polishing surface after corona treatment to form a primer layer; S3. Abrasives are implanted into the base adhesive layer to form an abrasive layer; S4. Perform initial curing treatment on the substrate after the abrasive layer is implanted; S5. Apply adhesive to the surface of the abrasive layer after initial curing to form an adhesive layer; S6. The substrate after coating with adhesive is subjected to primary curing treatment, followed by post-treatment, to obtain the grinding block.

2. The preparation method according to claim 1, characterized in that, In step S1, the organic-inorganic hybrid interface polar modifier comprises the following components by mass percentage: 0.5%~2.0% terminal amino hyperbranched polymer, 0.2%~1.0% silane-functionalized nano silica sol, and the balance being deionized water.

3. The preparation method according to claim 2, characterized in that: The amino-terminated hyperbranched polymer is at least one of amino-terminated hyperbranched polyamide-amine, amino-terminated hyperbranched polyethyleneimine, amino-terminated hyperbranched polyurethane, and amino-terminated hyperbranched polyether; the silane-functionalized nano-silica sol is an aminosilane or epoxysilane-modified nano-silica hydrosol with an average particle size of 15-30 nm; the aminosilane is at least one of γ-aminopropyltriethoxysilane, γ-aminopropyltrimethoxysilane, and N-(β-aminoethyl)-γ-aminopropyltrimethoxysilane, and the epoxysilane is γ-(2,3-epoxypropoxy)propyltrimethoxysilane.

4. The preparation method according to claim 1, characterized in that: In step S1, the coating amount of the organic-inorganic hybrid interface polar modifier is 5~15 g / m², and the drying treatment is baking at 40℃~50℃ for 5~10 minutes; the conditions for the corona treatment are: processing power of 1.0~3.0 kW and conveyor line speed of 5~20 m / min.

5. The preparation method according to claim 1, characterized in that: In step S1, the foam substrate is one of polyurethane foam material, ethylene-vinyl acetate copolymer foam material or polyethylene foam material, and its density is 30~80 kg / m³.

6. The preparation method according to claim 1, characterized in that: In step S2, the primer includes an aqueous resin matrix, a primary crosslinking agent, and a secondary crosslinking agent. The amount of the primary crosslinking agent is 1% to 3% of the mass of the aqueous resin matrix, and the amount of the secondary crosslinking agent is 0.5% to 1.5% of the mass of the aqueous resin matrix.

7. The preparation method according to claim 6, characterized in that: The waterborne resin matrix is ​​a waterborne polyurethane adhesive or a modified waterborne epoxy resin adhesive. The main crosslinking agent is at least one of a polyisocyanate crosslinking agent, a blocked polyisocyanate crosslinking agent, and a waterborne amino resin crosslinking agent. The auxiliary crosslinking agent is at least one of a polyaziridine crosslinking agent, a polycarbodiimide crosslinking agent, a waterborne oxazoline crosslinking agent, a waterborne epoxy crosslinking agent, and a waterborne silane crosslinking agent.

8. The preparation method according to claim 1, characterized in that: In step S4, the initial curing treatment is carried out at a temperature of 60℃~85℃ for 20~40 minutes.

9. The preparation method according to claim 1, characterized in that, In step S6, the main curing treatment adopts a stepped curing process, specifically: first, keep at 60℃~70℃ for 0.5~1 hour, and then raise the temperature to 90℃~110℃ and keep at 90℃~110℃ for 2~3 hours.

10. A grinding block based on a foam substrate, prepared by any one of claims 1-9.

Images