Melamine resin stone basin and preparation method thereof

Abstract

The invention provides a melamine resin stone basin and a preparation method thereof, and belongs to the technical field of artificial stone resines.The preparation method comprises the following steps that vinyl ester resin and a high-temperature curing agent are evenly mixed, and a mixture A is prepared; adding quartz sand, aluminum oxide, the mixture A and a silane coupling agent into a stirring kettle, and stirring and dispersing to obtain a mixture B; adding the mixture B, modified melamine resin, carbon powder and a lubricant into a stirring kettle, and stirring and dispersing to obtain a mixture C; the mixture C is preheated, hot-pressed, demolded, perforated, subjected to corner cutting and polished, and the melamine resin stone basin is obtained. The melamine resin stone basin has the advantages of being high in strength, resistant to high temperature, glossy, resistant to collision, resistant to chemical corrosion and the like, does not become white after being boiled in water at the high temperature, and is free of toxic and harmful migration substances.

Description

Technical Field

[0001] The invention belongs to the technical field of artificial stone resin, and particularly relates to a melamine resin stone basin and a preparation method thereof. Background Art

[0002] Resin stone basins offer advantages such as lightweight, waterproof, easy-to-clean, corrosion-resistant, and a variety of designs. They can withstand the demands of long-term use in humid environments. Their performance advantages have led to their widespread use in bathroom and kitchen appliances, such as washbasins, bathtubs, countertop basins, sinks, and decorative flower pots. Resin materials can be molded to mimic the grain and texture of natural stone, imparting a high-end aesthetic value while maintaining cost-effectiveness. This has led to them becoming a viable alternative to traditional ceramic or natural stone. With the dual demands of functionality and aesthetics in modern architecture, resin stone basins have expanded beyond their purely practical functions to include artistic designs, such as transparent, high-gloss, and antique-inspired shapes, further expanding their potential for interior decoration. However, existing resin stone basins still face limitations in terms of high-temperature resistance, strength, acid and alkali resistance, stain resistance, and long-term stability.

[0003] Traditional resin stone basins are mostly made of unsaturated polyester resins, vinyl ester resins, etc. as a matrix, and then mixed with mineral fillers such as quartz sand. Although these materials are lightweight and easy to process, they still have problems such as poor weather resistance, easy aging, and weak resistance to chemical corrosion. Melamine resin, also known as melamine formaldehyde resin, is a polymer obtained by the reaction of melamine and formaldehyde. Compared with traditional resins, melamine resin not only has the advantages of being resistant to knocks and collisions, low temperature resistance, chemical stability, non-toxicity, good sealing, and moisture resistance, but also can achieve high cleanliness requirements through surface smoothness. In addition, melamine resin is not easy to deform during long-term use, and its wear resistance and impact resistance can be improved through modification processes. Melamine resin provides a new direction for improving the performance defects of traditional resin stone basins.

[0004] In actual applications, stone basins made of quartz are prone to problems such as surface whitening and loss of gloss after long-term high-temperature boiling or cleaning under acidic or alkaline conditions, seriously affecting their aesthetics and service life. Existing technologies have attempted to avoid these problems by optimizing the formula and adding modified resins, but this has been difficult to completely prevent the expansion of micropores at the resin-filler interface at high temperatures. Other methods have attempted to enhance density by adding functional fillers, but the addition of excessive fillers can easily lead to increased brittleness and decreased impact resistance. Repair methods such as surface polishing and coating with protective agents can only temporarily improve the appearance and cannot fundamentally solve the problem of long-term material stability. Therefore, there is an urgent need to develop a method for preparing stone basins that combines high strength, high temperature resistance, gloss, and environmental friendliness. Summary of the Invention

[0005] The purpose of the present invention is to provide a melamine resin stone basin and a preparation method thereof. By compounding various raw materials, a stone basin with high strength, high temperature resistance, gloss, bump resistance, chemical corrosion resistance and impact resistance is produced, which solves the defect of existing quartz stone basins turning white when boiled in high temperature water, and does not contain toxic and harmful migrants.

[0006] In order to achieve the above object, the present invention provides the following technical solutions: The present invention provides a method for preparing a melamine resin stone basin, comprising the following steps: A1: Mix 95-100 parts by weight of vinyl ester resin and 0.5-2 parts by weight of curing agent to prepare mixture A. A2: Add 25-95 parts of quartz sand, 1-30 parts of aluminum oxide, 5-50 parts of mixture A, and 0.01-0.1 parts of silane coupling agent to a stirred tank and stir to prepare mixture B; A3: Add 40-85 parts of mixture B, 15-60 parts of modified melamine resin, 0.01-0.2 parts of carbon powder, and 0.2-2 parts of lubricant into a stirring vessel and stir to prepare mixture C; A4: Preheat the mixture C, then put it into a high-pressure mold and start hot pressing, keep it warm and pressurized, demould it, and then go through the processes of opening holes, cutting edges and corners, and polishing to obtain a melamine resin stone basin.

[0007] Preferably, the above preparation method comprises: A1: Mix 98-100 parts by weight of vinyl ester resin and 0.5-2 parts by weight of high-temperature curing agent to obtain mixture A. A2: Add 25-95 parts of quartz sand, 1-30 parts of aluminum oxide, 5-50 parts of mixture A, and 0.01-0.1 parts of silane coupling agent to a stirred tank, and stir and disperse for 30-50 minutes to prepare mixture B. A3: Add 40-85 parts of mixture B, 15-60 parts of modified melamine resin, 0.01-0.2 parts of carbon powder, and 0.2-2 parts of lubricant into a stirring vessel in sequence and stir and disperse for 30-50 minutes to prepare mixture C; A4: Weigh the dispersed mixed material C according to the mold specifications, place it in a high-frequency device for preheating, then place it in a high-pressure mold and start hot pressing. Keep the heat and pressure for 5 to 10 minutes, demold it, and then go through processes such as opening holes, cutting edges and corners, and polishing to obtain a melamine resin stone basin.

[0008] Preferably, the vinyl ester resin is at least one of a phenolic vinyl ester resin and a bisphenol A vinyl ester resin.

[0009] Preferably, the vinyl ester resin is a phenolic vinyl ester resin.

[0010] Preferably, the high-temperature curing agent is at least one of tert-butyl peroxybenzoate (TBPB), dibenzoyl peroxide (BPO), and tert-butyl peroxy-2-ethylhexanoate (TBPO).

[0011] Preferably, the high temperature curing agent is tert-butyl perbenzoate.

[0012] Preferably, the silane coupling agent is at least one of 3-aminopropyltrimethoxysilane, 3-aminopropyltriethoxysilane, and N-phenylaminomethyltriethoxysilane.

[0013] Preferably, the silane coupling agent is 3-aminopropyltrimethoxysilane.

[0014] Preferably, the lubricant is at least one of zinc stearate, ethylene bisstearamide, and oxidized polyethylene wax.

[0015] Preferably, the lubricant is zinc stearate.

[0016] Preferably, in steps A2 and A3, the rotation speed of the stirring tank is set to 100-500 r / min, and the temperature is set to 45-55°C.

[0017] Preferably, the preheating temperature in step A4 is set to 70-80°C.

[0018] Preferably, in step A4, the hot pressing pressure is set to 7-15 MPa and the temperature is set to 120-140°C.

[0019] The present invention selects modified melamine resin and vinyl ester resin as the main resin raw materials. The combination of these two resins can make the materials and processed products have the characteristics of chemical corrosion resistance and high temperature resistance. In addition, the high temperature and high pressure process conditions also give the finished stone basin the characteristics of high strength, scratch resistance, high gloss and beautiful appearance.

[0020] Preferably, the preparation method of the modified melamine resin comprises the following steps: Add melamine, paraformaldehyde, and water into a closed reactor, adjust the pH (e.g., to 8.0-9.0), heat to react, add urea to continue the reaction, then add polyethylene glycol and nano-cerium oxide, adjust the pH (e.g., to 6.0-7.0), heat to react, and cool to obtain a melamine resin prepolymer; The hydroxylated boron nitride nanosheets, sodium polyacrylate and ethanol solution were mixed, ultrasonicated, and ethyl orthosilicate and 3-aminopropyltrimethoxysilane were added. The mixture was heated for reaction, cooled, centrifuged and dried to obtain a core-shell reinforcement phase. Add melamine resin prepolymer, POE-g-GMA, core-shell reinforcement phase and silicon carbide whisker into a high-speed mixer, heat and stir, then add zinc stearate and triphenyl phosphite, heat and stir, and dry to obtain modified melamine resin.

[0021] In the preparation process of modified melamine resin, polyethylene glycol and urea are introduced into the melamine resin prepolymer to form a rigid-flexible interpenetrating network structure. The long polyethylene glycol chain is embedded in the melamine-formaldehyde rigid skeleton, and the COC ether bond increases the mobility of the molecular chain segments, thereby improving the impact strength. Urea forms hydroxymethyl urea with free formaldehyde groups, and the newly added cross-linking points significantly increase the cross-linking density, thereby improving the bending strength. Nano-cerium oxide captures high-temperature free radicals, inhibits the chain breakage of the long polyethylene glycol chain in the prepolymer, and ensures the long-term effectiveness of the flexible chain. The boron nitride nanosheets used in the core-shell reinforcement phase decrease the interlayer shear force after hydroxylation treatment, and micron-level slip occurs when impacted to absorb energy, and oxidation The silicon shell layer forms a Si-OC covalent bond through 3-aminopropyltrimethoxysilane and the hydroxymethyl group of melamine prepolymer. The bond energy is higher than the hydrogen bond of water molecules, which can block the water penetration path. Silicon carbide whiskers bridge the boron nitride sheets to form a three-dimensional thermal conductive network, thereby increasing the heat deformation temperature. In addition, the epoxy group of POE-g-GMA reacts with the hydroxymethyl group of melamine resin prepolymer. At the same time, the polyolefin chain entangles with the alkyl chain on the surface of the core-shell reinforcing phase, which improves the interfacial shear strength. Triphenyl phosphite chelates metal ions and scavenges free radicals, and cooperates with zinc stearate to form a hydrophobic film at the interface. After high-temperature water boiling, there is no hydrolysis and cracking at the resin-filler interface, achieving a simultaneous improvement in strength and temperature resistance.

[0022] Preferably, the weight ratio of melamine, paraformaldehyde, water, urea, polyethylene glycol and nano-cerium oxide is 5-15:5-15:10-20:0.6-1:1-2:0.05-0.1.

[0023] Preferably, the weight ratio of the hydroxylated boron nitride nanosheets, sodium polyacrylate, ethyl orthosilicate, and 3-aminopropyltrimethoxysilane is 1-2:0.01-0.02:0.5-0.8:0.1-0.2.

[0024] Preferably, the weight ratio of the melamine resin prepolymer, POE-g-GMA, core-shell reinforcement phase, silicon carbide whiskers, zinc stearate, and triphenyl phosphite is 5-15:0.1-0.5:0.5-2:0.1-0.2:0.04-0.06:0.05-0.1.

[0025] Preferably, the preparation method of the modified melamine resin comprises the following steps: The method comprises the following steps: adding 5 to 15 parts of melamine, 5 to 15 parts of paraformaldehyde, and 10 to 20 parts of water into a sealed reaction kettle, adjusting the pH to 8.0 to 9.0 with 8 to 15 wt% sodium hydroxide solution, reacting at 70 to 80° C. for 30 to 50 minutes, adding 0.6 to 1 part of urea, and continuing the reaction for 20 to 40 minutes, then adding 1 to 2 parts of polyethylene glycol and 0.05 to 0.1 part of nano-cerium oxide, adjusting the pH to 6.0 to 7.0 with 10 to 20 wt% citric acid solution, heating to 80 to 90° C., reacting for 1 to 2 hours, and cooling to room temperature to obtain a melamine resin prepolymer; 1-2 parts of hydroxylated boron nitride nanosheets, 0.01-0.02 parts of sodium polyacrylate and 3-8 parts of 80-90 wt% ethanol solution were mixed and ultrasonicated for 20-40 min. 0.5-0.8 parts of ethyl orthosilicate and 0.1-0.2 parts of 3-aminopropyltrimethoxysilane were added and reacted at 50-60° C. for 1-2 h, then heated to 60-70° C. for 1-3 h, cooled to room temperature, centrifuged and dried to obtain a core-shell reinforcement phase. 5-15 parts of melamine resin prepolymer, 0.1-0.5 parts of POE-g-GMA, 0.5-2 parts of core-shell reinforcement phase, and 0.1-0.2 parts of silicon carbide whiskers are added into a high-speed stirrer, and stirred at 60-70°C and 1000-1300 r / min for 7-15 minutes. Then, 0.04-0.06 parts of zinc stearate and 0.05-0.1 parts of triphenyl phosphite are added, and stirred at 60-70°C and 500-700 r / min for 20-40 minutes, and dried to obtain a modified melamine resin.

[0026] Preferably, the polyethylene glycol is at least one of PEG-1000, PEG-1500, and PEG-2000.

[0027] Preferably, the frequency of the ultrasound is 30-45 kHz and the power is 250-400 W.

[0028] The present invention also provides a melamine resin stone basin, which is prepared by adopting the above method.

[0029] The present invention also provides the use of the melamine resin stone basin in bathroom appliances and kitchen appliances, including but not limited to wash basins, bathtubs, table basins, cleaning pools or decorative flower pots.

[0030] Compared with the prior art, the advantages and beneficial effects of the present invention are: (1) The melamine resin stone basin preparation method of the present invention selects modified melamine resin and vinyl ester resin as the main resin raw materials. Through the compounding and synergistic effect of the raw materials, the final stone basin product not only has excellent properties such as high strength, high temperature resistance, gloss, bump resistance, chemical corrosion resistance, and impact resistance, but also has the advantages of light weight, high appearance, high surface hardness, scratch resistance, good crack resistance, good high humidity stability, good solvent resistance, and alkali resistance. It solves the defect of the existing quartz stone basin turning white when boiled in high temperature water, and does not contain toxic and harmful migrants.

[0031] (2) The modified melamine resin used in the present invention introduces polyethylene glycol and urea into the prepolymer to form a rigid-flexible interpenetrating network structure. The long polyethylene glycol chain is embedded in the melamine-formaldehyde rigid skeleton to improve the impact strength. The urea forms hydroxymethyl urea with the free formaldehyde group. The newly added cross-linking points significantly increase the cross-linking density. Nano-cerium oxide captures high-temperature free radicals and inhibits the chain breakage of the polyethylene glycol long chain in the prepolymer, thereby ensuring the long-term effectiveness of the flexible chain. The boron nitride nanosheets used in the core-shell reinforcement phase absorb energy by micron-scale slip when impacted. The silicon oxide shell forms a Si-OC covalent bond with the hydroxymethyl group of the melamine prepolymer through 3-aminopropyltrimethoxysilane, which can block the water penetration path. The silicon carbide whiskers bridge the boron nitride sheet layer to form a three-dimensional thermal conductive network, thereby improving the thermal deformation temperature. DETAILED DESCRIPTION

[0032] The following is a clear and complete description of the technical solutions in the embodiments of the present invention. Obviously, the embodiments described are only some embodiments of the present invention, not all embodiments. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without making any creative efforts are within the scope of protection of the present invention.

[0033] The raw materials used in the examples and comparative examples of the present invention were all homemade or commercially available, and some of the raw materials are described as follows: Vinyl ester resin: Phenolic vinyl ester resin with the brand name OY-8007 was purchased from Shanghai Ouyang Chemical Co., Ltd.

[0034] Quartz sand: Model HS-40, purchased from Jiangsu Kaida Quartz Co., Ltd.

[0035] Alumina: Model: Brofos-Al2O3-W45, purchased from Bohuasi Nanotechnology (Ningbo) Co., Ltd.

[0036] Commercially available melamine resin: A1 melamine powder was used and purchased from Shandong Aojin Chemical Technology Co., Ltd.

[0037] Toner: Model: Brofos-C-W01, purchased from Bohuasi Nanotechnology (Ningbo) Co., Ltd.

[0038] Melamine: CAS number 108-78-1, purchased from Shandong Xinheng Chemical Co., Ltd.

[0039] Paraformaldehyde: CAS number 30525-89-4, purchased from Shandong Chuangying Chemical Co., Ltd.

[0040] Polyethylene glycol: model PEG-1500, purchased from Hai'an (Linyi) Guoli Chemical Co., Ltd.

[0041] Nano-cerium oxide: model Brofos-CeO2-200, purchased from Bohuasi Nano-Technology (Ningbo) Co., Ltd.

[0042] Hydroxylated boron nitride nanosheets: Model XFBN03-2, purchased from Jiangsu Xianfeng Nanomaterial Technology Co., Ltd.

[0043] Sodium polyacrylate: Model NP-700, purchased from Shanghai Lianmai Bioengineering Co., Ltd.

[0044] POE-g-GMA: polyolefin grafted glycidyl methacrylate, model number SOG-02, purchased from Jiayirong Polymer (Shanghai) Co., Ltd.

[0045] Silicon carbide whiskers: model 1404045, diameter 1.5 μm, length 18 μm, purchased from Forsman Technology (Beijing) Co., Ltd.

[0046] Example 1 A melamine resin stone basin, the preparation method of which comprises the following steps: A1: Mixture A was prepared by uniformly mixing 100 parts of vinyl ester resin and 2 parts of tert-butyl perbenzoate by weight. A2: 95 parts of quartz sand, 30 parts of aluminum oxide, 50 parts of mixture A, and 0.1 parts of a silane coupling agent were sequentially added to a stirred tank and stirred and dispersed for 50 minutes at a speed of 200 r / min and a temperature of 55°C to prepare mixture B; the silane coupling agent was 3-aminopropyltrimethoxysilane; A3: 85 parts of mixture B, 60 parts of modified melamine resin, 0.2 parts of carbon powder, and 2 parts of zinc stearate were added to a stirring vessel in sequence and stirred and dispersed for 50 minutes at a speed of 200 r / min and a temperature of 55°C to obtain mixture C. A4: Weigh the dispersed mixture C according to the mold specifications, place it in a high-frequency equipment for preheating, and set the preheating temperature to 80℃. Then put it into a high-pressure mold and start hot pressing. The hot pressing pressure is set to 15MPa and the temperature is set to 140℃. Keep the heat and pressure for 5 minutes, demold it, and then go through processes such as opening holes, cutting edges and corners, and polishing to obtain a melamine resin stone basin.

[0047] The preparation method of the modified melamine resin comprises the following steps: In parts by weight, 10 parts of melamine, 9.5 parts of paraformaldehyde, and 12 parts of water were added to a closed reactor, the pH was adjusted to 8.5 with a 10 wt % sodium hydroxide solution, the reaction was carried out at 75° C. for 40 minutes, 0.8 parts of urea were added and the reaction was continued for 30 minutes, 1.2 parts of polyethylene glycol and 0.08 parts of nano-cerium oxide were added, the pH was adjusted to 6.5 with a 15 wt % citric acid solution, the temperature was raised to 85° C., the reaction was carried out for 1.5 hours, and the mixture was cooled to room temperature to obtain a melamine resin prepolymer; 1.5 parts of hydroxylated boron nitride nanosheets, 0.01 parts of sodium polyacrylate and 5 parts of 90 wt% ethanol solution were mixed and ultrasonically treated at an ultrasonic frequency of 40 kHz and a power of 300 W for 30 min. 0.6 parts of ethyl orthosilicate and 0.15 parts of 3-aminopropyltrimethoxysilane were added and reacted at 55°C for 1 h, then heated to 65°C for 2 h, cooled to room temperature, centrifuged and dried to obtain a core-shell reinforcement phase. 10 parts of melamine resin prepolymer, 0.3 parts of POE-g-GMA, 1 part of core-shell reinforcement phase, and 0.12 parts of silicon carbide whiskers were added into a high-speed mixer and stirred at 65°C and 1200 r / min for 10 minutes. Then, 0.05 parts of zinc stearate and 0.08 parts of triphenyl phosphite were added, and the mixture was stirred at 65°C and 600 r / min for 30 minutes. The mixture was dried to obtain a modified melamine resin.

[0048] Example 2 A melamine resin stone basin, the preparation method of which comprises the following steps: A1: Mixture A was prepared by uniformly mixing 99 parts of vinyl ester resin and 1 part of tert-butyl perbenzoate by weight. A2: 50 parts of quartz sand, 15 parts of aluminum oxide, 25 parts of mixture A, and 0.05 parts of a silane coupling agent were added to a stirred tank in sequence and stirred and dispersed for 40 minutes at a speed of 350 r / min and a temperature of 45°C to prepare mixture B; the silane coupling agent was 3-aminopropyltrimethoxysilane; A3: 65 parts of mixture B, 35 parts of modified melamine resin, 0.1 part of carbon powder, and 1 part of zinc stearate were added to a stirring vessel in sequence and stirred and dispersed for 40 minutes at a speed of 350 r / min and a temperature of 45°C to obtain mixture C. A4: Weigh the dispersed mixture C according to the mold specifications, place it in a high-frequency equipment for preheating, and set the preheating temperature to 75℃. Then put it into a high-pressure mold and start hot pressing. The hot pressing pressure is set to 10MPa and the temperature is set to 130℃. Keep the heat and pressure for 8 minutes, demold it, and then go through processes such as opening holes, cutting edges and corners, and polishing to obtain a melamine resin stone basin.

[0049] The preparation method of the modified melamine resin is the same as that in Example 1.

[0050] Example 3 A melamine resin stone basin, the preparation method of which comprises the following steps: A1: Mix 98 parts by weight of vinyl ester resin and 0.5 parts by weight of tert-butyl perbenzoate to obtain a mixture A. A2: 25 parts of quartz sand, 1 part of aluminum oxide, 5 parts of mixture A, and 0.01 parts of a silane coupling agent were sequentially added to a stirred tank and stirred and dispersed for 30 minutes at a speed of 500 r / min and a temperature of 50°C to prepare mixture B; the silane coupling agent was 3-aminopropyltrimethoxysilane; A3: 40 parts of mixture B, 15 parts of modified melamine resin, 0.01 parts of carbon powder, and 0.2 parts of zinc stearate were added to a stirring vessel in sequence and stirred and dispersed for 30 minutes at a speed of 500 r / min and a temperature of 50°C to obtain mixture C. A4: Weigh the dispersed mixture C according to the mold specifications, place it in a high-frequency equipment for preheating, and set the preheating temperature to 70℃. Then put it into a high-pressure mold and start hot pressing. Set the hot pressing pressure to 7MPa and the temperature to 120℃. Keep the heat and pressure for 10 minutes, demold it, and then go through processes such as opening holes, cutting edges and corners, and polishing to obtain a melamine resin stone basin.

[0051] The preparation method of the modified melamine resin is the same as that in Example 1.

[0052] Comparative Example 1 The difference between this comparative example and Example 1 is that the preparation method of the modified melamine resin is different, which is as follows: the preparation method of the modified melamine resin comprises the following steps: 10 parts by weight of melamine, 9.5 parts of paraformaldehyde, and 12 parts of water were added to a closed reactor, the pH was adjusted to 8.5 with a 10 wt % sodium hydroxide solution, and the mixture was reacted at 75° C. for 40 min. 1.2 parts of polyethylene glycol and 0.08 parts of nano-cerium oxide were added, the pH was adjusted to 6.5 with a 15 wt % citric acid solution, the temperature was raised to 85° C., the mixture was reacted for 1.5 h, and the mixture was cooled to room temperature to obtain a melamine resin prepolymer. 1.5 parts of hydroxylated boron nitride nanosheets, 0.01 parts of sodium polyacrylate and 5 parts of 90 wt% ethanol solution were mixed and ultrasonically treated at an ultrasonic frequency of 40 kHz and a power of 300 W for 30 min. 0.6 parts of ethyl orthosilicate and 0.15 parts of 3-aminopropyltrimethoxysilane were added and reacted at 55°C for 1 h, then heated to 65°C for 2 h, cooled to room temperature, centrifuged and dried to obtain a core-shell reinforcement phase. 10 parts of melamine resin prepolymer, 0.3 parts of POE-g-GMA, 1 part of core-shell reinforcement phase, and 0.12 parts of silicon carbide whiskers were added into a high-speed mixer and stirred at 65°C and 1200 r / min for 10 minutes. Then, 0.05 parts of zinc stearate and 0.08 parts of triphenyl phosphite were added, and the mixture was stirred at 65°C and 600 r / min for 30 minutes. The mixture was dried to obtain a modified melamine resin.

[0053] Comparative Example 2 The difference between this comparative example and Example 1 is that the preparation method of the modified melamine resin is different, which is as follows: the preparation method of the modified melamine resin comprises the following steps: 10 parts by weight of melamine, 9.5 parts of paraformaldehyde, and 12 parts of water were added to a closed reactor, the pH was adjusted to 8.5 with a 10 wt % sodium hydroxide solution, the reaction was carried out at 75° C. for 40 minutes, 0.8 parts of urea were added and the reaction was continued for 30 minutes, 0.08 parts of nano-cerium oxide were added, the pH was adjusted to 6.5 with a 15 wt % citric acid solution, the temperature was raised to 85° C., the reaction was carried out for 1.5 hours, and the mixture was cooled to room temperature to obtain a melamine resin prepolymer; 1.5 parts of hydroxylated boron nitride nanosheets, 0.01 parts of sodium polyacrylate and 5 parts of 90 wt% ethanol solution were mixed and ultrasonically treated at an ultrasonic frequency of 40 kHz and a power of 300 W for 30 min. 0.6 parts of ethyl orthosilicate and 0.15 parts of 3-aminopropyltrimethoxysilane were added and reacted at 55°C for 1 h, then heated to 65°C for 2 h, cooled to room temperature, centrifuged and dried to obtain a core-shell reinforcement phase. 10 parts of melamine resin prepolymer, 0.3 parts of POE-g-GMA, 1 part of core-shell reinforcement phase, and 0.12 parts of silicon carbide whiskers were added into a high-speed mixer and stirred at 65°C and 1200 r / min for 10 minutes. Then, 0.05 parts of zinc stearate and 0.08 parts of triphenyl phosphite were added, and the mixture was stirred at 65°C and 600 r / min for 30 minutes. The mixture was dried to obtain a modified melamine resin.

[0054] Comparative Example 3 The difference between this comparative example and Example 1 is that the preparation method of the modified melamine resin is different, which is as follows: the preparation method of the modified melamine resin comprises the following steps: In parts by weight, 10 parts of melamine, 9.5 parts of paraformaldehyde, and 12 parts of water were added to a closed reactor, the pH was adjusted to 8.5 with a 10 wt % sodium hydroxide solution, the reaction was carried out at 75° C. for 40 minutes, 0.8 parts of urea were added and the reaction was continued for 30 minutes, 1.2 parts of polyethylene glycol were added, the pH was adjusted to 6.5 with a 15 wt % citric acid solution, the temperature was raised to 85° C., the reaction was carried out for 1.5 hours, and the mixture was cooled to room temperature to obtain a melamine resin prepolymer; 1.5 parts of hydroxylated boron nitride nanosheets, 0.01 parts of sodium polyacrylate and 5 parts of 90 wt% ethanol solution were mixed and ultrasonically treated at an ultrasonic frequency of 40 kHz and a power of 300 W for 30 min. 0.6 parts of ethyl orthosilicate and 0.15 parts of 3-aminopropyltrimethoxysilane were added and reacted at 55°C for 1 h, then heated to 65°C for 2 h, cooled to room temperature, centrifuged and dried to obtain a core-shell reinforcement phase. 10 parts of melamine resin prepolymer, 0.3 parts of POE-g-GMA, 1 part of core-shell reinforcement phase, and 0.12 parts of silicon carbide whiskers were added into a high-speed mixer and stirred at 65°C and 1200 r / min for 10 minutes. Then, 0.05 parts of zinc stearate and 0.08 parts of triphenyl phosphite were added, and the mixture was stirred at 65°C and 600 r / min for 30 minutes. The mixture was dried to obtain a modified melamine resin.

[0055] Comparative Example 4 The difference between this comparative example and Example 1 is that the preparation method of the modified melamine resin is different, which is as follows: the preparation method of the modified melamine resin comprises the following steps: In parts by weight, 10 parts of melamine, 9.5 parts of paraformaldehyde, and 12 parts of water were added to a closed reactor, the pH was adjusted to 8.5 with a 10 wt % sodium hydroxide solution, the reaction was carried out at 75° C. for 40 minutes, 0.8 parts of urea were added and the reaction was continued for 30 minutes, 1.2 parts of polyethylene glycol and 0.08 parts of nano-cerium oxide were added, the pH was adjusted to 6.5 with a 15 wt % citric acid solution, the temperature was raised to 85° C., the reaction was carried out for 1.5 hours, and the mixture was cooled to room temperature to obtain a melamine resin prepolymer; 1.5 parts of aluminum oxide, 0.01 parts of sodium polyacrylate and 5 parts of 90 wt% ethanol solution were mixed and ultrasonically treated at an ultrasonic frequency of 40 kHz and a power of 300 W for 30 min. 0.6 parts of ethyl orthosilicate and 0.15 parts of 3-aminopropyltrimethoxysilane were added, and the mixture was reacted at 55°C for 1 h, then heated to 65°C for 2 h, cooled to room temperature, centrifuged, and dried to obtain a core-shell reinforcement phase. 10 parts of melamine resin prepolymer, 0.3 parts of POE-g-GMA, 1 part of core-shell reinforcement phase, and 0.12 parts of silicon carbide whiskers were added into a high-speed mixer and stirred at 65°C and 1200 r / min for 10 minutes. Then, 0.05 parts of zinc stearate and 0.08 parts of triphenyl phosphite were added, and the mixture was stirred at 65°C and 600 r / min for 30 minutes. The mixture was dried to obtain a modified melamine resin.

[0056] Comparative Example 5 The difference between this comparative example and Example 1 is that the preparation method of the modified melamine resin is different, which is as follows: the preparation method of the modified melamine resin comprises the following steps: In parts by weight, 10 parts of melamine, 9.5 parts of paraformaldehyde, and 12 parts of water were added to a closed reactor, the pH was adjusted to 8.5 with a 10 wt % sodium hydroxide solution, the reaction was carried out at 75° C. for 40 minutes, 0.8 parts of urea were added and the reaction was continued for 30 minutes, 1.2 parts of polyethylene glycol and 0.08 parts of nano-cerium oxide were added, the pH was adjusted to 6.5 with a 15 wt % citric acid solution, the temperature was raised to 85° C., the reaction was carried out for 1.5 hours, and the mixture was cooled to room temperature to obtain a melamine resin prepolymer; 10 parts of melamine resin prepolymer, 0.3 parts of POE-g-GMA, 1 part of hydroxylated boron nitride nanosheets, and 0.12 parts of silicon carbide whiskers were added into a high-speed mixer and stirred at 65°C and 1200 r / min for 10 minutes. Then, 0.05 parts of zinc stearate and 0.08 parts of triphenyl phosphite were added, and the mixture was stirred at 65°C and 600 r / min for 30 minutes. The mixture was dried to obtain a modified melamine resin.

[0057] Comparative Example 6 The difference between this comparative example and Example 1 is that the preparation method of the modified melamine resin is different, which is as follows: the preparation method of the modified melamine resin comprises the following steps: In parts by weight, 10 parts of melamine, 9.5 parts of paraformaldehyde, and 12 parts of water were added to a closed reactor, the pH was adjusted to 8.5 with a 10 wt % sodium hydroxide solution, the reaction was carried out at 75° C. for 40 minutes, 0.8 parts of urea were added and the reaction was continued for 30 minutes, 1.2 parts of polyethylene glycol and 0.08 parts of nano-cerium oxide were added, the pH was adjusted to 6.5 with a 15 wt % citric acid solution, the temperature was raised to 85° C., the reaction was carried out for 1.5 hours, and the mixture was cooled to room temperature to obtain a melamine resin prepolymer; 1.5 parts of hydroxylated boron nitride nanosheets, 0.01 parts of sodium polyacrylate and 5 parts of 90 wt% ethanol solution were mixed and ultrasonically treated at an ultrasonic frequency of 40 kHz and a power of 300 W for 30 min. 0.6 parts of ethyl orthosilicate and 0.15 parts of 3-aminopropyltrimethoxysilane were added and reacted at 55°C for 1 h, then heated to 65°C for 2 h, cooled to room temperature, centrifuged and dried to obtain a core-shell reinforcement phase. 10 parts of melamine resin prepolymer, 0.3 parts of POE-g-GMA, and 1 part of core-shell reinforcing phase were added to a high-speed mixer and stirred at 65°C and 1200 r / min for 10 minutes. Then, 0.05 parts of zinc stearate and 0.08 parts of triphenyl phosphite were added, and the mixture was stirred at 65°C and 600 r / min for 30 minutes. The mixture was dried to obtain a modified melamine resin.

[0058] Comparative Example 7 The difference between this comparative example and Example 1 is that the modified melamine resin is replaced by a commercially available melamine resin.

[0059] Performance Testing The following properties of the melamine resin stone basin materials described in Examples 1 to 3 and Comparative Examples 1 to 7 were tested, and the results are shown in Table 1. The flexural strength of the material was tested according to the method of national standard GB / T 9341-2008, the impact strength was tested according to the method of national standard GB / T1043.1-2008 (type A notch), and the thermal decomposition temperature T 5％ Thermogravimetric analyzer was used for analysis (nitrogen atmosphere, heating rate of 10°C / min), and the moisture and heat resistance and dry heat resistance were evaluated with reference to the national standard GB / T41001-2021.

[0060] Table 1: Performance test results of melamine resin stone basin materials <![CDATA[Impact strength (kJ / m 2 )]]> Flexural strength (MPa) <![CDATA[Thermal decomposition temperature T 5％ (°C)]]> Dry heat resistance Moisture and heat resistance Example 1 2.59 103.5 289.7 No cracks, no obvious fading No cracks, no obvious whitening Example 2 2.30 100.8 288.0 No cracks, no obvious fading No cracks, no obvious whitening Example 3 2.14 99.0 286.6 No cracks, no obvious fading No cracks, no obvious whitening Comparative Example 1 1.85 92.3 284.5 No cracks, no obvious fading No cracks, no obvious whitening Comparative Example 2 1.60 94.0 285.7 No cracks, no obvious fading No cracks, no obvious whitening Comparative Example 3 2.01 97.6 277.9 No cracks, no obvious fading No cracks, no obvious whitening Comparative Example 4 1.49 98.0 281.3 No cracks, no obvious fading No cracks, no obvious whitening Comparative Example 5 1.78 95.2 280.5 No cracks, no obvious fading No cracks, no obvious whitening Comparative Example 6 2.08 98.3 275.6 No cracks, no obvious fading No cracks, no obvious whitening Comparative Example 7 1.30 87.7 270.8 No cracks, no obvious fading No cracks, no obvious whitening From the results in Table 1 above, it can be seen that the melamine resin stone basin materials described in Examples 1 to 3 have properties such as high impact strength, high bending strength and high temperature resistance, among which the melamine resin stone basin material described in Example 1 has the best comprehensive performance. This is because the present invention further improves the strength and high temperature resistance of the melamine resin stone basin material by adopting a modified melamine resin prepared by a specific method. Compared with Examples 1 to 3, since Comparative Examples 1 to 3 do not use urea, polyethylene glycol or nano-cerium oxide in the preparation of melamine resin prepolymers, Comparative Examples 4 to 5 do not use a specific core-shell reinforcing phase, Comparative Example 6 does not use silicon carbide whiskers, and Comparative Example 7 directly uses commercially available melamine resin, this results in the bending strength, impact strength and high temperature resistance of the melamine resin stone basin materials described in Comparative Examples 1 to 7 all showing a decrease of varying degrees, that is, the technical solution to be protected by the present invention has achieved beneficial technical effects.

[0061] The above is a preferred embodiment of the present invention. It should be pointed out that for ordinary technicians in this technical field, several improvements and modifications can be made without departing from the principles of the present invention. These improvements and modifications should also be regarded as within the scope of protection of the present invention.

Claims

1. A method for preparing a melamine resin stone basin, characterized in that: The following steps are involved: A1: Mix 95-100 parts by weight of vinyl ester resin and 0.5-2 parts by weight of curing agent to prepare mixture A. A2: Add 25-95 parts of quartz sand, 1-30 parts of aluminum oxide, 5-50 parts of mixture A, and 0.01-0.1 parts of silane coupling agent to a stirred tank and stir to prepare mixture B; A3: Add 40-85 parts of mixture B, 15-60 parts of modified melamine resin, 0.01-0.2 parts of carbon powder, and 0.2-2 parts of lubricant into a stirring vessel and stir to prepare mixture C; A4: Preheat the mixture C, then put it into a high-pressure mold and start hot pressing, keep it warm and pressurized, demould it, and then go through the processes of opening holes, cutting edges and corners, and polishing to obtain a melamine resin stone basin.

2. The method for preparing a melamine resin stone basin according to claim 1, wherein: The preparation method of the modified melamine resin comprises the following steps: Melamine, paraformaldehyde and water are added to a closed reactor, the pH is adjusted, the reaction is heated, urea is added to continue the reaction, polyethylene glycol and nano-cerium oxide are added, the pH is adjusted, the temperature is increased to react, and the reaction is cooled to obtain a melamine resin prepolymer; The hydroxylated boron nitride nanosheets, sodium polyacrylate and ethanol solution were mixed, ultrasonicated, and ethyl orthosilicate and 3-aminopropyltrimethoxysilane were added. The mixture was heated for reaction, cooled, centrifuged and dried to obtain a core-shell reinforcement phase. Add melamine resin prepolymer, POE-g-GMA, core-shell reinforcement phase and silicon carbide whisker into a high-speed mixer, heat and stir, then add zinc stearate and triphenyl phosphite, heat and stir, and dry to obtain modified melamine resin.

3. The method for preparing a melamine resin stone basin according to claim 2, wherein: The weight ratio of melamine, paraformaldehyde, water, urea, polyethylene glycol, and nano-cerium oxide is 5-15:5-15:10-20:0.6-1:1-2:0.05-0.1; the weight ratio of hydroxylated boron nitride nanosheets, sodium polyacrylate, ethyl orthosilicate, and 3-aminopropyltrimethoxysilane is 1-2:0.01-0.02:0.5-0.8:0.1-0.2; and the weight ratio of melamine resin prepolymer, POE-g-GMA, core-shell reinforcement phase, silicon carbide whiskers, zinc stearate, and triphenyl phosphite is 5-15:0.1-0.5:0.5-2:0.1-0.2:0.04-0.06:0.05-0.

1.

4. The method for preparing a melamine resin stone basin according to claim 2, wherein: The polyethylene glycol is at least one of PEG-1000, PEG-1500, and PEG-2000.

5. The method for preparing a melamine resin stone basin according to claim 1, wherein: The vinyl ester resin is at least one of a phenolic vinyl ester resin and a bisphenol A vinyl ester resin.

6. The method for preparing a melamine resin stone basin according to claim 1, wherein: The high-temperature curing agent is at least one of tert-butyl perbenzoate, dibenzoyl peroxide, and tert-butyl peroxy-2-ethylhexanoate.

7. The method for preparing a melamine resin stone basin according to claim 1, wherein: The silane coupling agent is at least one of 3-aminopropyltrimethoxysilane, 3-aminopropyltriethoxysilane, and N-phenylaminomethyltriethoxysilane.

8. The method for preparing a melamine resin stone basin according to claim 1, wherein: The lubricant is at least one of zinc stearate, ethylene bisstearamide, and oxidized polyethylene wax.

9. The method for preparing a melamine resin stone basin according to claim 1, wherein: In steps A2 and A3, the speed of the stirred tank is set to 100-500 r / min and the temperature is set to 45-55°C; in step A4, the preheating temperature is set to 70-80°C; in step A4, the hot pressing pressure is set to 7-15 MPa and the temperature is set to 120-140°C.

10. A melamine resin stone basin, characterized in that: Prepared according to the method according to any one of claims 1 to 9.