A hot-pressing assisted dual-curing mirror coating and a forming process thereof

Abstract

The present application belongs to the technical field of polymer coating, and particularly relates to a hot-pressing assisted double-curing mirror coating and a forming process thereof. The hot-pressing assisted double-curing mirror coating is prepared from a double-curing coating, and the double-curing coating is mainly composed of a photo-curing resin, a photo-curing monomer, an epoxy resin, diamond nanosheets, zirconium oxide coated aluminum trioxide and a photo initiator. The functional ultraviolet light curing monomer with a branched and reticular structure is synthesized, and the triazole ring, piperazine ring, spiro ring and thiazole ring in the functional ultraviolet light curing monomer can improve the affinity and bonding strength between the inorganic wear-resistant particles through hydrogen bond and other forces, ensure the uniformity of the distribution and the stability of the combination of the inorganic wear-resistant particles in the coating, and further improve the gloss uniformity, wear resistance and impact resistance of the coating. The spiro ring structure simultaneously endows the coating with good flexibility and rigidity, and the four double bonds can participate in chemical crosslinking in the photo-curing stage, so that the wear-resistant particles are stably imprisoned in the coating.

Description

TECHNICAL FIELD

[0001] The present application belongs to the technical field of polymer coating, in particular to a hot-pressing assisted double-curing mirror surface coating and a forming process thereof. BACKGROUND

[0002] The glazed tile in the ground decoration material refers to the ceramic tile with glaze layer on the tile surface. The tile is divided into two categories: one is made of clay and must be glazed due to high water absorption, which has low strength and is easy to crack, and is rarely used now; the other is made of porcelain clay and is glazed to pursue decorative effect, which has dense structure, high strength, low water absorption and strong pollution resistance, and is slightly more expensive than the clay-made ceramic tile. The glazed tile has soft and gorgeous color, smoothness and strong decoration, and can be assembled into any pattern, cooperates with other indoor decorations and forms unique decorative effect. The porcelain clay-made glazed tile is currently widely used in home decoration.

[0003] The production process of the glazed tile is mainly roller coating and film pressing process. Limited by the thickness of the glaze, in order to obtain the glazed tile with high surface quality, the tolerance of the substrate should be ensured to be less than or equal to 0.3 mm. However, the high temperature in the firing process is difficult to control, which leads to a certain number of unqualified products, resulting in the qualified rate of the glazed tile less than 70%. In addition, the glazed tile has problems of hard and brittle, poor wear resistance and insufficient impact resistance, which affects its wide use. Therefore, it is urgent to provide a wear-resistant and impact-resistant mirror surface coating that can replace the traditional glaze layer. SUMMARY

[0004] In view of the above problems, the present application provides a hot-pressing assisted double-curing mirror surface coating and a forming process thereof, which solves the problem of poor wear resistance and impact resistance of the glaze layer on the surface of the current glazed tile.

[0005] To achieve the above-mentioned purpose, the technical scheme adopted by the present application is as follows:

[0006] A hot-pressing assisted double-curing mirror surface coating is prepared from a double-curing coating material, the double-curing coating material mainly consists of photocuring resin, photocuring monomer, epoxy resin, diamond nanosheet, zirconium oxide coated aluminum trioxide and photoinitiator, the photocuring monomer includes functional ultraviolet photocuring monomer, the preparation method of the zirconium oxide coated aluminum trioxide is as follows: first, nanometer aluminum trioxide, water, polyethylene glycol phosphate quaternary ammonium salt, zirconium oxychloride and aluminum chloride are mixed and reacted to obtain an intermediate, then the intermediate, water, polyethylene glycol phosphate quaternary ammonium salt and zirconium oxychloride are mixed and reacted to obtain the zirconium oxide coated aluminum trioxide; the structure of the functional ultraviolet photocuring monomer is as follows:

[0007] ;

[0008] The structure of the polyethylene glycol phosphate quaternary ammonium salt is as follows:

[0009]

[0010] Preferably, the average flake diameter of the diamond nanosheet is 50-80 nm.

[0011] Preferably, the photocuring monomer further comprises 2-acrylic acid-2-[[(butylamino)- carbonyl]oxy]ethyl ester, trimethylolpropane triacrylate and tripropylene glycol diacrylate.

[0012] Preferably, the photocuring resin is aliphatic polyurethane acrylate; the epoxy resin is epoxy resin E51; and the dual-curing coating further comprises a mold release aid, which is isooctanol phosphate.

[0013] Preferably, the photocuring resin and photocuring monomer form a photocuring mixture, and the mass ratio of the photocuring mixture, the epoxy resin, the diamond nanosheet, the zirconium oxide-coated aluminum trioxide, the photoinitiator and the mold release aid is 50-60:20-30:5-8:10-15:3-5:0.5-1; and the mass ratio of the aliphatic polyurethane acrylate, the functional ultraviolet photocuring monomer, 2-acrylic acid-2-[[(butylamino)-carbonyl]oxy]ethyl ester, trimethylolpropane triacrylate and tripropylene glycol diacrylate is 27-30:30-35:10-15:7-10:18-20.

[0014] Preferably, the method for preparing the intermediate is as follows: mixing nano-aluminum trioxide, water and polyethylene glycol phosphate quaternary ammonium salt to obtain a nano-aluminum trioxide dispersion; then adding a mixed solution of zirconium oxychloride and aluminum chloride, and adjusting the pH of the reaction system to 8.5-9 with ammonia water, and incubating at 60-65℃ for 2-3h, and after solid-liquid separation, washing the obtained solid to obtain the intermediate; the mass of the polyethylene glycol phosphate quaternary ammonium salt is 1-3% of the mass of the nano-aluminum trioxide, the mass fraction of the nano-aluminum trioxide in the nano-aluminum trioxide dispersion is 6-8%; the total mass fraction of the zirconium oxychloride and the aluminum chloride in the mixed solution of the zirconium oxychloride and the aluminum chloride is 4-6%, and the mass ratio of the zirconium oxychloride to the aluminum chloride is 2-3:4-5; and the ratio of the mass of the nano-aluminum trioxide in the nano-aluminum trioxide dispersion to the mass of the zirconium oxychloride in the mixed solution of the zirconium oxychloride and the aluminum chloride is 1.5-2.5:1.

[0015] ​Preferably, the method for preparing zirconia-coated aluminum trioxide by using the intermediate is as follows: the intermediate, water and polyethylene glycol phosphate quaternary ammonium salt are mixed to obtain an intermediate dispersion liquid; then, a zirconyl chloride solution is added, and the pH of the reaction system is adjusted to 8.5-9 by using ammonia water, and the reaction is carried out at 60-65 DEG C for 5-7 h; after solid-liquid separation, the obtained solid is washed, dried and calcined to obtain zirconia-coated aluminum trioxide; the mass of the polyethylene glycol phosphate quaternary ammonium salt is 1-3% of the mass of the intermediate; the mass fraction of the intermediate in the intermediate dispersion liquid is 8-10%; the mass fraction of zirconyl chloride in the zirconyl chloride solution is 7-9%; and the ratio of the mass of the intermediate in the intermediate dispersion liquid to the mass of zirconyl chloride in the zirconyl chloride solution is 4-6:1.

[0016] Preferably, the average particle size of the nano-aluminum trioxide is 10-20 nm.

[0017] A forming process of the hot-pressing assisted double-cured mirror surface coating as described above, comprising the following steps: coating the double-cured coating on the surface of a substrate, and then sequentially performing light curing, hot pressing and heat curing to obtain the hot-pressing assisted double-cured mirror surface coating.

[0018] Preferably, the energy density of the ultraviolet light for the light curing is 200-400 mJ / cm 2 , and the time is 20-30 s; the temperature for the hot pressing is 100-120 DEG C, the pressure is 3-5 MPa, and the time is 10-30 s; and the temperature for the heat curing is 140-160 DEG C, and the time is 20-40 min.

[0019] The hot-pressing assisted double-cured mirror surface coating and the forming process thereof have the following advantages:

[0020] (1) The functional ultraviolet light curing monomer with branched and network structure is synthesized, the flexible dimer acid structure, rigid triazole ring, rigid thiazole ring, rigid piperazine ring, silicon atom, spiro ring and polyene structure in the molecular chain of the functional ultraviolet light curing monomer are used to endow the coating with good adhesion, gloss uniformity, scratch resistance, wear resistance and impact resistance; the triazole ring, piperazine ring, spiro ring and thiazole ring in the functional ultraviolet light curing monomer can improve the affinity and bonding strength between the inorganic wear-resistant particles in the coating through hydrogen bond and other forces, ensure the uniformity and stability of the distribution of the inorganic wear-resistant particles in the coating, and further improve the gloss uniformity, wear resistance and impact resistance of the coating; the spiro ring structure in the functional ultraviolet light curing monomer simultaneously endows the coating with good flexibility and rigidity, four double bonds can form good chemical crosslinking with the light curing resin and monomer in the light curing stage, further stabilize and confine the wear-resistant particles in the coating, the flexible long fatty chain and the rigid heteroatom ring can avoid the agglomeration of the inorganic wear-resistant particles in the coating on one hand, and adjust the rigidity and toughness of the coating on the other hand, so that the coating has high hardness and high toughness, and the wear resistance and impact resistance of the coating are improved.

[0021] (2) The application improves the bonding strength and uniformity of zirconium oxide on the surface of aluminum oxide by first coating the surface of nano-aluminum oxide with a precursor of zirconium oxide and aluminum oxide as a transition layer, then coating the transition layer with a precursor of zirconium oxide, and finally obtaining zirconium oxide coated aluminum oxide by calcination. The overall strength and integrity of the zirconium oxide coated aluminum oxide are improved, and the zirconium oxide on the surface of the particles is prevented from falling off or being damaged when the surface is scratched, thereby affecting the overall performance of the coating. The application also synthesizes polyethylene glycol phosphate quaternary ammonium salt, which has a branched structure and contains a large number of quaternary ammonium salt groups, phosphate groups and alcohol ether structures. The polyethylene glycol phosphate quaternary ammonium salt has excellent surface activity, which can improve the dispersibility of nano-aluminum oxide and the uniformity of the distribution of the precursors of zirconium oxide and aluminum oxide. The precursors are also uniformly close to the surface of nano-aluminum oxide, thereby improving the uniformity of the transition layer of zirconium oxide and aluminum oxide and the uniformity of the pure zirconium oxide layer, reducing surface defects, and improving the strength and wear resistance of the zirconium oxide coated aluminum oxide.

[0022] (3) The application realizes 1.2mm substrate defect filling (12 times of film pressing process) by a heat pressing assisted double curing process, and the prepared coating reaches EN16094 B2 level wear resistance. The elastic network of the bottom layer ensures that the 1.5m drop ball does not crack, and at the same time, the replication mirror surface precision (Ra≤0.01μm) is realized, which can effectively improve the wear resistance and surface quality of the glazed ceramic tile, and is suitable for the preparation of mirror surface coating on the surface of SPC floor, ceramic tile, wallboard and other substrates. The application prepares a mirror surface coating by a three-step process. Photocuring can form a plastic gel network; the heat pressing process can compensate for the defects of the substrate and can fill 1.2mm recesses / protuberances, improve the qualified rate of the finished product, reduce the substrate tolerance, and realize mirror surface zero orange peel and densification of the wear-resistant layer; and the heat curing completes the final crosslinking and locks the morphology. The application can replace the traditional high-temperature sintering process to achieve the purpose of energy saving and consumption reduction and improving product quality. BRIEF DESCRIPTION OF DRAWINGS

[0023] Figure 1 The nuclear magnetic hydrogen spectrum of the polyethylene glycol phosphate quaternary ammonium salt prepared in the examples is shown in the figure, the horizontal coordinate is the chemical shift δ, the unit is ppm, and the vertical coordinate is the intensity;

[0024] Figure 2 The nuclear magnetic hydrogen spectrum of the spirothioethanol prepared in Example 1 is shown in the figure, the horizontal coordinate is the chemical shift δ, the unit is ppm, and the vertical coordinate is the intensity;

[0025] Figure 3 The nuclear magnetic hydrogen spectrum of the branched polyol prepared in Example 1 is shown in the figure, the horizontal coordinate is the chemical shift δ, the unit is ppm, and the vertical coordinate is the intensity;

[0026] Figure 4The nuclear magnetic resonance hydrogen spectrum of the functional ultraviolet light curing monomer prepared in Example 1 has a horizontal coordinate of chemical shift δ in ppm and a vertical coordinate of intensity.

[0027] Figure 5 The appearance diagram of the hot-pressing assisted double curing mirror coating prepared in Example 1;

[0028] Figure 6 The appearance diagram of the hot-pressing assisted double curing mirror coating of Example 1 after the abrasion resistance test is completed.

[0029] Figure 7 The appearance diagram of the hot-pressing assisted double curing mirror coating of Comparative Example 1 after the abrasion resistance test is completed. DETAILED DESCRIPTION

[0030] In order to make the skilled in the art better understand the technical solutions, the application will be described in detail below in conjunction with examples, and the description in this part is only exemplary and explanatory, and should not have any limiting effect on the protection scope of the application.

[0031] The preparation method of the polyethylene glycol phosphate quaternary ammonium salt used in the following examples is as follows:

[0032] (1) A 35% by mass bromoacetyl chloride solution in dichloromethane was added dropwise to a 40% by mass polyethylene glycol (PEG400) solution in dichloromethane under stirring at 0°C, and then triethylamine was added. The reaction was stirred at room temperature for 6 h, and then filtered. The filtrate was distilled under reduced pressure to obtain brominated polyethylene glycol. The molar ratio of bromoacetyl chloride, polyethylene glycol and triethylamine was 1:1:1.3.

[0033] (2) The brominated polyethylene glycol, triisopentylamine and ethyl acetate were added to a reaction kettle, heated to 80°C, and stirred to reflux for 10 h. The product was distilled under reduced pressure to obtain quaternary ammonium saltified polyethylene glycol. The molar ratio of brominated polyethylene glycol and triisopentylamine was 1:1.1, and the mass of ethyl acetate was 1.5 times the sum of the masses of brominated polyethylene glycol and triisopentylamine.

[0034] (3) A 25% by mass phosphorus oxychloride solution in dichloromethane was added dropwise to a 35% by mass quaternary ammonium saltified polyethylene glycol solution in dichloromethane under stirring at -5°C, and then triethylamine was added. The reaction was stirred at room temperature for 6 h, and then filtered. The filtrate was distilled under reduced pressure to obtain a concentrated solution. The concentrated solution was purified by column chromatography using petroleum ether, ethyl acetate and dichloromethane (6:2:1 by volume) as eluents to obtain polyethylene glycol phosphate quaternary ammonium salt. The molar ratio of phosphorus oxychloride, quaternary ammonium saltified polyethylene glycol and triethylamine was 1:3:3.2. The nuclear magnetic resonance hydrogen spectrum of the polyethylene glycol phosphate quaternary ammonium salt is shown in Figure 1 ​

[0035] Example 1

[0036] The hot-pressing assisted double-curing mirror coating of the present example is prepared by a method comprising the following steps:

[0037] (1) A mass ratio of 4:6 of spiroglycol and pyridine is added to a reaction kettle, stirred uniformly, and then heated to 70°C. Then, under stirring, thionyl chloride is added dropwise to the reaction kettle. After the dropwise addition is completed, stirring is continued for 3h, and the solvent is removed by distillation under reduced pressure to obtain a spiroglycol chlorination product. The molar ratio of spiroglycol to thionyl chloride is 1:2.1.

[0038] (2) A mass fraction of 30% of sodium dithiocarbonate solution and a mass fraction of 35% of spiroglycol chlorination product tetrahydrofuran solution are added to a reaction kettle, stirred uniformly, and then heated to 65°C. Stirring is continued for 6h, and the reaction product is extracted with ethyl acetate. The organic phase obtained by extraction is distilled under reduced pressure and then purified by column chromatography to obtain spiroglycol dithiol. The molar ratio of sodium dithiocarbonate to spiroglycol chlorination product is 2.5:1. The eluent used for column chromatography purification is composed of ethyl acetate, dichloromethane and methanol in a volume ratio of 7:3:1. The nuclear magnetic hydrogen spectrum of spiroglycol dithiol is shown in Figure 2 , and the chemical structure is as follows:

[0039] .

[0040] (3) Magnolol, 5,5-dimethyl-2-(piperazin-1-yl)-4,5-dihydrothiazole, triethylamine and toluene are added to a reaction kettle, stirred uniformly, and then heated to 70°C. Stirring is continued for 5h, and the solvent is removed by distillation under reduced pressure to obtain modified magnolol. The molar ratio of magnolol, 5,5-dimethyl-2-(piperazin-1-yl)-4,5-dihydrothiazole and triethylamine is 1:1:0.2. The mass of toluene is 150% of the sum of the masses of magnolol and 5,5-dimethyl-2-(piperazin-1-yl)-4,5-dihydrothiazole. The chemical structure of modified magnolol is as follows:

[0041] .

[0042] (4) Put modified magnolol, 2-(2,3-epoxypropylthio) thiophene, toluene and benzyl dimethylamine into a reaction kettle, stir uniformly, heat to 80°C, stir for 6h, remove the solvent by distillation under reduced pressure to obtain grafted magnolol; wherein the molar ratio of modified magnolol and 2-(2,3-epoxypropylthio) thiophene is 1:2, the mass of toluene is 2.5 times the sum of the mass of modified magnolol and 2-(2,3-epoxypropylthio) thiophene, and the mass of benzyl dimethylamine is 1% of the sum of the mass of modified magnolol and 2-(2,3-epoxypropylthio) thiophene. The chemical structure of grafted magnolol is as follows:

[0043] .

[0044] (5) Put 1-(oxirane-2-ylmethyl)-1H-1,2,4-triazole, dimer acid, toluene and tetrabutylammonium chloride into a reaction kettle, stir uniformly, heat to 110°C, stir and reflux for 3h, remove the solvent by distillation under reduced pressure to obtain grafted dimer acid; wherein the molar ratio of 1-(oxirane-2-ylmethyl)-1H-1,2,4-triazole, dimer acid and tetrabutylammonium chloride is 2:1:0.01, and the mass of toluene is 3 times the sum of the mass of 1-(oxirane-2-ylmethyl)-1H-1,2,4-triazole, dimer acid and tetrabutylammonium chloride. The chemical structure of dimer acid is as follows:

[0045] .

[0046] The chemical structure of grafted dimer acid is as follows:

[0047] .

[0048] (6) Put grafted dimer acid, spiroethanedithiol, toluene and 1,8-bisdimethylaminonaphthalene into a reaction kettle, heat to 80°C, stir for 5h, then put grafted magnolol into the reaction kettle, heat to 95°C, stir for 6h, remove the solvent by distillation under reduced pressure to obtain a concentrate, and purify the concentrate by column chromatography with ethyl acetate, dichloromethane and methanol in a volume ratio of 8:2:2 to obtain a branched polyol; wherein the molar ratio of grafted dimer acid, spiroethanedithiol and grafted magnolol is 1:1:1, the mass of toluene is 3 times the sum of the mass of grafted dimer acid and spiroethanedithiol, and the mass of 1,8-bisdimethylaminonaphthalene is 5% of the sum of the mass of grafted dimer acid and spiroethanedithiol. The proton nuclear magnetic resonance spectrum of the branched polyol is as shown in Figure 3 , and the chemical structure is as follows:

[0049] .

[0050] (7) Put the branched polyol and toluene into the reaction kettle, stir uniformly, then add dimethylvinylchlorosilane into the reaction kettle dropwise, add triethylamine into the reaction kettle, heat to 70℃, stir for 8h, cool to room temperature, then filter, distill the filtrate under reduced pressure to obtain a concentrated solution, purify the concentrated solution by column chromatography with ethyl acetate and dichloromethane in a volume ratio of 7:3 to obtain the functional ultraviolet light curing monomer; wherein the molar ratio of the branched polyol, dimethylvinylchlorosilane and triethylamine is 1:4.1:4.5, the mass of toluene is 90% of the mass of the branched polyol, and the nuclear magnetic resonance spectrum of the functional ultraviolet light curing monomer is as shown in Figure 4 , and the chemical structure is as follows:

[0051] .

[0052] (8) Put the aliphatic polyurethane diacrylate, functional ultraviolet light curing monomer, 2-acrylic acid-2-[[(butylamino)-carbonyl]oxy]ethyl ester, trimethylolpropane triacrylate and tripropylene glycol diacrylate into the stirring kettle, stir uniformly to obtain a light curing mixture; wherein the mass ratio of the aliphatic polyurethane diacrylate, functional ultraviolet light curing monomer, 2-acrylic acid-2-[[(butylamino)-carbonyl]oxy]ethyl ester, trimethylolpropane triacrylate and tripropylene glycol diacrylate is 27:30:10:7:18, and the preparation method of the aliphatic polyurethane diacrylate is as follows: put polytetrahydrofuran ether diol PTME650, IPDI and dibutyltin dilaurate into the reaction kettle, heat to 80℃, stir for 5h, then add hydroxyethyl acrylate, heat to 90℃, continue to stir for 2h, cool to room temperature to obtain the aliphatic polyurethane diacrylate, and the molar ratio of the polytetrahydrofuran ether diol PTME650, IPDI and hydroxyethyl acrylate is 1:2:2, and the mass of the dibutyltin dilaurate is 0.03% of the sum of the masses of the polytetrahydrofuran ether diol PTME650 and IPDI.

[0053] (9) Put the light curing mixture, epoxy resin, diamond nanosheet, zirconia coated aluminum trioxide, photoinitiator TPO and release aid into the stirring kettle, stir uniformly to obtain a dual-curing type coating; wherein the epoxy resin is epoxy resin E51, the release aid is isooctanol phosphate (to ensure that the steel plate and the coating film can be smoothly separated after hot pressing), and the mass ratio of the light curing mixture, epoxy resin, diamond nanosheet, zirconia coated aluminum trioxide, photoinitiator TPO and release aid is 50:20:5:10:3:0.5; the average flake diameter of the diamond nanosheet is 50nm; and the preparation method of the zirconia coated aluminum trioxide is as follows:

[0054] ① Nano-alumina with an average particle size of 10 nm, water, and a dispersant were added to a stirred tank and stirred until homogeneous to obtain a nano-alumina dispersion. Then, a mixed solution of zirconium oxychloride and aluminum chloride was added to the stirred tank under stirring conditions. After homogeneity, the pH of the material in the stirred tank was adjusted to 9 with ammonia water, heated to 60°C, and kept at that temperature for 2 hours. After the reaction was completed, the mixture was filtered, and the filter cake was repeatedly washed with distilled water until no chloride ions were detected in the filtrate. Finally, it was washed with anhydrous alcohol to obtain an intermediate. The dispersant was polyethylene glycol phosphate quaternary ammonium salt, and the mass of the dispersant was 1% of the mass of nano-alumina. The mass fraction of nano-alumina in the nano-alumina dispersion was 6%. The total mass fraction of zirconium oxychloride and aluminum chloride in the mixed solution was 4%, and the mass ratio of zirconium oxychloride to aluminum chloride was 2:4. The mass ratio of nano-alumina in the nano-alumina dispersion to the mass of zirconium oxychloride in the mixed solution was 1.5:1.

[0055] ② The intermediate, water, and dispersant were added to a stirred tank and stirred until homogeneous to obtain an intermediate dispersion. Then, under stirring conditions, a zirconium oxychloride solution was added to the stirred tank and stirred until homogeneous. The pH of the material in the stirred tank was adjusted to 9 with ammonia water. The mixture was heated to 60℃ and kept at this temperature for 5 hours. After the reaction, the mixture was filtered, and the filter cake was repeatedly washed with distilled water until no chloride ions were detected in the filtrate. Finally, it was washed with anhydrous alcohol, dried, and calcined in a muffle furnace at 500℃ for 5 hours to obtain zirconium oxide-coated alumina. The dispersant was polyethylene glycol phosphate quaternary ammonium salt, with a mass of 1% of the intermediate mass. The mass fraction of the intermediate in the intermediate dispersion was 8%. The mass fraction of zirconium oxychloride in the zirconium oxychloride solution was 7%. The mass ratio of the intermediate in the intermediate dispersion to the zirconium oxychloride in the zirconium oxychloride solution was 4:1. The chemical structure of polyethylene glycol phosphate quaternary ammonium salt is as follows:

[0056] .

[0057] (10) A dual-curing coating is applied to the surface of a marble substrate to form a 100 μm thick film. The film is then cured by UV irradiation. A mirror-finished steel plate (Ra≤0.01 μm) is used to hot-press the cured film. Finally, the hot-pressed film is heat-cured to obtain a hot-pressed assisted dual-curing mirror coating, with the appearance as shown in the image. Figure 5 As shown; the surface roughness of the marble substrate is 1.0 mm; the UV energy density of the photocured light is 300 mJ / cm². 2 The hot pressing temperature is 120℃, the pressure is 4MPa, and the time is 15s; the heat curing temperature is 150℃ and the time is 30min.

[0058] Example 2

[0059] The hot-pressing assisted double-curing mirror coating of the present embodiment is prepared by a method comprising the following steps:

[0060] (1) A reaction kettle is charged with spiroethanediol and pyridine in a mass ratio of 4.5:6, and stirred uniformly, and then heated to 75℃, and then sulfur chloride is added dropwise to the reaction kettle under stirring, after the dropwise addition is completed, the stirring reaction is continued for 4h, and the solvent is removed by distillation under reduced pressure to obtain a spiroethanediol chlorination product; wherein the molar ratio of spiroethanediol to sulfur chloride is 1:2.2.

[0061] (2) A reaction kettle is charged with a 32% by mass sodium dithiocarbonate solution and a 37% by mass spiroethanediol chlorination product tetrahydrofuran solution, and stirred uniformly, and then heated to 68℃, and then stirred for 7h, and then cooled to room temperature, and then the reaction product is extracted with ethyl acetate, and then the organic phase obtained by extraction is distilled under reduced pressure, and then column chromatography purification is performed to obtain spiroethanedithiol; wherein the molar ratio of sodium dithiocarbonate to spiroethanediol chlorination product is 2.8:1, the eluent used in column chromatography purification is composed of ethyl acetate, dichloromethane and methanol in a volume ratio of 7:3:1, and the chemical structure of spiroethanedithiol is as follows:

[0062] .

[0063] (3) A reaction kettle is charged with magnolol, 5,5-dimethyl-2-(piperazin-1-yl)-4,5-dihydrothiazole, triethylamine and toluene, and stirred uniformly, and then heated to 75℃, and then stirred for 6h, and then the solvent is removed by distillation under reduced pressure to obtain modified magnolol; wherein the molar ratio of magnolol, 5,5-dimethyl-2-(piperazin-1-yl)-4,5-dihydrothiazole and triethylamine is 1:1:0.25, and the mass of toluene is 170% of the sum of the masses of magnolol and 5,5-dimethyl-2-(piperazin-1-yl)-4,5-dihydrothiazole.

[0064] (4) A reaction kettle is charged with modified magnolol, 2-(2,3-epoxypropylthio)thiophene, toluene and benzyldimethylamine, and stirred uniformly, and then heated to 85℃, and then stirred for 7h, and then the solvent is removed by distillation under reduced pressure to obtain grafted magnolol; wherein the molar ratio of modified magnolol to 2-(2,3-epoxypropylthio)thiophene is 1:2, the mass of toluene is 2.8 times the sum of the masses of modified magnolol and 2-(2,3-epoxypropylthio)thiophene, and the mass of benzyldimethylamine is 2% of the sum of the masses of modified magnolol and 2-(2,3-epoxypropylthio)thiophene.

[0065] (5) 1-(oxane-2-ylmethyl)-1H-1,2,4-triazole, dimeric acid, toluene and tetrabutylammonium chloride were added into a reaction kettle, and after being stirred uniformly, heating was performed to 115°C, and reflux reaction was performed for 4 h under stirring, and then solvent was removed by distillation under reduced pressure to obtain grafted dimeric acid; wherein the molar ratio of 1-(oxane-2-ylmethyl)-1H-1,2,4-triazole, dimeric acid and tetrabutylammonium chloride was 2:1:0.01, and the mass of tetrahydrofuran was 3.2 times the sum of the masses of 1-(oxane-2-ylmethyl)-1H-1,2,4-triazole, dimeric acid and tetrabutylammonium chloride. The chemical structure of the dimeric acid is as follows:

[0066] .

[0067] (6) Grafted dimeric acid, spiroethanedithiol, toluene and 1,8-bisdimethylaminonaphthalene were added into a reaction kettle, heating was performed to 78°C, and reaction was performed for 6 h under stirring, then grafted magnolol was added into the reaction kettle, heating was performed to 92°C, and reaction was performed for 7 h under stirring, and then solvent was removed by distillation under reduced pressure to obtain a concentrate, and the concentrate was purified by column chromatography using ethyl acetate, dichloromethane and methanol in a volume ratio of 8:2:2 to obtain a branched polyol; wherein the molar ratio of grafted dimeric acid, spiroethanedithiol and grafted magnolol was 1:1:1, the mass of toluene was 3.3 times the sum of the masses of grafted dimeric acid and spiroethanedithiol, and the mass of 1,8-bisdimethylaminonaphthalene was 6% of the sum of the masses of grafted dimeric acid and spiroethanedithiol.

[0068] (7) The branched polyol and toluene were added into a reaction kettle, and after being stirred uniformly, dimethylvinylchlorosilane was added dropwise into the reaction kettle, and then triethylamine was added into the reaction kettle, and then the temperature was raised to 72°C, and reaction was performed for 9 h under stirring, and then the temperature was lowered to room temperature, and then filtration was performed, and then the filtrate was distilled under reduced pressure to obtain a concentrate, and then the concentrate was purified by column chromatography using ethyl acetate and dichloromethane in a volume ratio of 7:3 to obtain a functional ultraviolet light curing monomer; wherein the molar ratio of the branched polyol, dimethylvinylchlorosilane and triethylamine was 1:4.2:4.6, and the mass of toluene was 110% of the mass of the branched polyol, and the chemical structure of the functional ultraviolet light curing monomer is as follows:

[0069] .

[0070] (8)aliphatic polyurethane diacrylate, functional ultraviolet light curing monomer, 2-acrylic acid-2-[[(butylamino)-carbonyl]oxy]ethyl ester, trimethylolpropane triacrylate and tripropylene glycol diacrylate are added into a stirring kettle, and stirred uniformly to obtain a light curing mixture; the mass ratio of aliphatic polyurethane diacrylate, functional ultraviolet light curing monomer, 2-acrylic acid-2-[[(butylamino)-carbonyl]oxy]ethyl ester, trimethylolpropane triacrylate and tripropylene glycol diacrylate is 28:32:13:9:19, and the preparation method of aliphatic polyurethane diacrylate is as follows: polytetrahydrofuran ether diol PTME650, IPDI and dibutyl tin dilaurate are added into a reaction kettle, heated to 83℃, and stirred for 6h, then hydroxyethyl acrylate is added, heated to 90℃, and continuously stirred for 2.5h, and then cooled to room temperature to obtain aliphatic polyurethane diacrylate; the molar ratio of polytetrahydrofuran ether diol PTME650, IPDI and hydroxyethyl acrylate is 1:2:2, and the mass of dibutyl tin dilaurate is 0.05% of the sum of the mass of polytetrahydrofuran ether diol PTME650 and IPDI.

[0071] (9)the light curing mixture, epoxy resin, diamond nanosheet, zirconium oxide coated aluminum oxide, photoinitiator TPO and demolding aid are added into a stirring kettle, and stirred uniformly to obtain a dual-curing coating; the epoxy resin is epoxy resin E51, and the demolding aid is isooctanol phosphate; the mass ratio of the light curing mixture, epoxy resin, diamond nanosheet, zirconium oxide coated aluminum oxide, photoinitiator TPO and demolding aid is 55:25:7:12:4:0.7; the average flake diameter of the diamond nanosheet is 60nm; and the preparation method of the zirconium oxide coated aluminum oxide is as follows:

[0072] ①the average particle size of the nanometer aluminum oxide is 15nm, water and a dispersing agent are added into a stirring kettle, and stirred uniformly to obtain a nanometer aluminum oxide dispersion liquid; then a mixed solution of zirconium oxychloride and aluminum chloride is added into the stirring kettle under stirring, and stirred uniformly, then the pH of the material in the stirring kettle is adjusted to 9 by using ammonia water, heated to 62℃, and kept for 2.5h, then filtered after the reaction is completed, and the filter cake is repeatedly washed with distilled water until no chloride ion is detected in the filtrate, and finally washed with anhydrous alcohol to obtain an intermediate; the dispersing agent is polyethylene glycol phosphate quaternary ammonium salt, the mass of the dispersing agent is 2% of the mass of the nanometer aluminum oxide, and the mass fraction of the nanometer aluminum oxide in the nanometer aluminum oxide dispersion liquid is 7%; the total mass fraction of zirconium oxychloride and aluminum chloride in the mixed solution of zirconium oxychloride and aluminum chloride is 5%, and the mass ratio of zirconium oxychloride to aluminum chloride is 2.5:4.5; the mass ratio of the nanometer aluminum oxide in the nanometer aluminum oxide dispersion liquid to the zirconium oxychloride in the mixed solution of zirconium oxychloride and aluminum chloride is 2:1.

[0073] (2) adding the intermediate, water and dispersant into a stirring kettle, stirring uniformly to obtain an intermediate dispersion liquid; then adding the zirconium oxychloride solution into the stirring kettle under stirring, adjusting the pH of the material in the stirring kettle to 9 with ammonia water, heating to 62°C, and keeping the temperature for 6h, after the reaction is completed, filtering, and repeatedly washing the filter cake with distilled water until no chloride ion is detected in the filtrate, finally washing with anhydrous alcohol, and drying and calcining in a muffle furnace at 520°C for 4h to obtain the zirconium oxide coated aluminum trioxide; wherein the dispersant is polyethylene glycol phosphate quaternary ammonium salt, the mass of the dispersant is 2% of the mass of the intermediate, the mass fraction of the intermediate in the intermediate dispersion liquid is 9%, the mass fraction of the zirconium oxychloride in the zirconium oxychloride solution is 8%, and the ratio of the mass of the intermediate in the intermediate dispersion liquid to the mass of the zirconium oxychloride in the zirconium oxychloride solution is 5:1. The chemical structure of the polyethylene glycol phosphate quaternary ammonium salt is as follows:

[0074] .

[0075] (10) applying the dual-curable coating on the surface of the marble substrate by spraying to form a coating film with a thickness of 100μm, then performing light curing on the coating film by irradiating with ultraviolet light, then performing hot pressing on the light-cured coating film by using a mirror surface steel plate (the Ra of the steel plate is ≤0.01μm), and finally performing heat curing on the hot-pressed coating film to obtain a hot-pressing-assisted dual-cured mirror surface coating; wherein the roughness of the surface of the marble substrate is 1.0mm; the energy density of the ultraviolet light for light curing is 300mJ / cm 2 , and the time is 25s; the temperature for hot pressing is 120°C, the pressure is 4MPa, and the time is 15s; and the temperature for heat curing is 150°C, and the time is 30min.

[0076] Example 3

[0077] The hot-pressing-assisted dual-cured mirror surface coating of the present example is prepared by a method comprising the following steps:

[0078] (1) adding spirocyclic glycol and pyridine with a mass ratio of 5:6 into a reaction kettle, stirring uniformly, and then heating to 80°C, then adding thionyl chloride into the reaction kettle under stirring, after the addition is completed, continuing to stir for 5h, and removing the solvent by distillation under reduced pressure to obtain a spirocyclic glycol chlorination product; wherein the molar ratio of spirocyclic glycol to thionyl chloride is 1:2.3.

[0079] (2) A 35% by mass sodium dithiocarbonate solution and a 40% by mass tetrahydrofuran solution of the chlorination product of spiroethanediol were added to a reaction kettle, stirred uniformly, heated to 70°C, stirred and reacted for 8 hours, cooled to room temperature, and the reaction product was extracted with ethyl acetate. The organic phase obtained by extraction was distilled under reduced pressure and then purified by column chromatography to obtain spiroethanedithiol. The molar ratio of sodium dithiocarbonate to the chlorination product of spiroethanediol was 3:1, and the eluent used for column chromatography purification was composed of ethyl acetate, dichloromethane, and methanol at a volume ratio of 7:3:1. The chemical structure of spiroethanedithiol is as follows:

[0080] .

[0081] (3) Magnolol, 5,5-dimethyl-2-(piperazin-1-yl)-4,5-dihydrothiazole, triethylamine, and toluene were added to a reaction kettle, stirred uniformly, heated to 80°C, stirred and reacted for 7 hours, and the solvent was removed by distillation under reduced pressure to obtain modified magnolol. The molar ratio of magnolol, 5,5-dimethyl-2-(piperazin-1-yl)-4,5-dihydrothiazole, and triethylamine was 1:1:0.3, and the mass of toluene was 180% of the sum of the masses of magnolol and 5,5-dimethyl-2-(piperazin-1-yl)-4,5-dihydrothiazole.

[0082] (4) Modified magnolol, 2-(2,3-epoxypropylthio)thiophene, toluene, and benzyldimethylamine were added to a reaction kettle, stirred uniformly, heated to 90°C, stirred and reacted for 8 hours, and the solvent was removed by distillation under reduced pressure to obtain grafted magnolol. The molar ratio of modified magnolol to 2-(2,3-epoxypropylthio)thiophene was 1:2, the mass of toluene was 3 times the sum of the masses of modified magnolol and 2-(2,3-epoxypropylthio)thiophene, and the mass of benzyldimethylamine was 3% of the sum of the masses of modified magnolol and 2-(2,3-epoxypropylthio)thiophene.

[0083] (5) 1-(Oxetan-2-ylmethyl)-1H-1,2,4-triazole, dimer acid, toluene, and tetrabutylammonium chloride were added to a reaction kettle, stirred uniformly, heated to 120°C, stirred and refluxed for 5 hours, and the solvent was removed by distillation under reduced pressure to obtain grafted dimer acid. The molar ratio of 1-(oxetan-2-ylmethyl)-1H-1,2,4-triazole, dimer acid, and tetrabutylammonium chloride was 2:1:0.02, and the mass of tetrahydrofuran was 3.5 times the sum of the masses of 1-(oxetan-2-ylmethyl)-1H-1,2,4-triazole, dimer acid, and tetrabutylammonium chloride. The chemical structure of dimer acid is as follows:

[0084] .

[0085] (6) grafting dimeric acid, spirocyclic ethanedithiol, toluene and 1,8-bisdimethylaminonaphthalene were added into a reaction kettle, heated to 75°C, stirred for 8h, then grafting magnolol was added into the reaction kettle, heated to 90°C, stirred for 9h, and the solvent was removed by distillation under reduced pressure to obtain a concentrate, which was purified by column chromatography with ethyl acetate, dichloromethane and methanol in a volume ratio of 8:2:2 to obtain a branched polyol; wherein the molar ratio of grafting dimeric acid, spirocyclic ethanedithiol and grafting magnolol was 1:1:1, the mass of toluene was 3.5 times the sum of the mass of grafting dimeric acid and spirocyclic ethanedithiol, and the mass of 1,8-bisdimethylaminonaphthalene was 8% of the sum of the mass of grafting dimeric acid and spirocyclic ethanedithiol.

[0086] (7) branched polyol and toluene were added into a reaction kettle, stirred uniformly, then dimethylvinylchlorosilane was added dropwise into the reaction kettle, and triethylamine was added into the reaction kettle, heated to 75°C, stirred for 10h, cooled to room temperature, filtered, and the filtrate was distilled under reduced pressure to obtain a concentrate, which was purified by column chromatography with ethyl acetate and dichloromethane in a volume ratio of 7:3 to obtain a functional ultraviolet light curing monomer; wherein the molar ratio of branched polyol, dimethylvinylchlorosilane and triethylamine was 1:4.2:4.8, and the mass of toluene was 120% of the mass of branched polyol, and the chemical structure of the functional ultraviolet light curing monomer was as follows:

[0087] .

[0088] (8) aliphatic polyurethane diacrylate, functional ultraviolet light curing monomer, 2-acrylic acid-2-[[(butylamino)-carbonyl]oxy]ethyl ester, trimethylolpropane triacrylate and tripropylene glycol diacrylate were added into a stirring kettle, stirred uniformly to obtain a light curing mixture; wherein the mass ratio of aliphatic polyurethane diacrylate, functional ultraviolet light curing monomer, 2-acrylic acid-2-[[(butylamino)-carbonyl]oxy]ethyl ester, trimethylolpropane triacrylate and tripropylene glycol diacrylate was 30:35:15:10:20, and the preparation method of aliphatic polyurethane diacrylate was as follows: polytetrahydrofuran ether diol PTME650, IPDI and dibutyltin dilaurate were added into a reaction kettle, heated to 85°C, stirred for 7h, then hydroxyethyl acrylate was added, heated to 90°C and continued to stir for 3h, and cooled to room temperature to obtain aliphatic polyurethane diacrylate, and the molar ratio of polytetrahydrofuran ether diol PTME650, IPDI and hydroxyethyl acrylate was 1:2:2, and the mass of dibutyltin dilaurate was 0.06% of the sum of the mass of polytetrahydrofuran ether diol PTME650 and IPDI.

[0089] (9) The photocuring mixture, epoxy resin, diamond nanosheet, zirconium oxide coated aluminum trioxide, photoinitiator TPO and demolding aid are added into a stirring kettle, and stirred uniformly to obtain a dual-curing coating; wherein the epoxy resin is epoxy resin E51, the demolding aid is isooctanol phosphate, and the mass ratio of the photocuring mixture, epoxy resin, diamond nanosheet, zirconium oxide coated aluminum trioxide, photoinitiator TPO and demolding aid is 60:30:8:15:5:1; the average flake diameter of the diamond nanosheet is 80 nm; and the zirconium oxide coated aluminum trioxide is prepared by the following method:

[0090] ① The nano-aluminum trioxide with an average particle size of 20 nm, water and a dispersant are added into a stirring kettle, and stirred uniformly to obtain a nano-aluminum trioxide dispersion liquid; then a mixed solution of zirconium oxychloride and aluminum chloride is added into the stirring kettle under stirring, and after being stirred uniformly, the pH of the materials in the stirring kettle is adjusted to 9 by using ammonia water, heated to 65℃, and kept for 3 h of reaction; after the reaction is completed, the filter cake is repeatedly washed with distilled water until no chloride ion is detected in the filtrate, and finally washed with anhydrous alcohol to obtain an intermediate; wherein the dispersant is polyethylene glycol phosphate quaternary ammonium salt, the mass of the dispersant is 3% of the mass of the nano-aluminum trioxide, and the mass fraction of the nano-aluminum trioxide in the nano-aluminum trioxide dispersion liquid is 8%; the total mass fraction of zirconium oxychloride and aluminum chloride in the mixed solution of zirconium oxychloride and aluminum chloride is 6%, and the mass ratio of zirconium oxychloride to aluminum chloride is 3:5; the mass ratio of the nano-aluminum trioxide in the nano-aluminum trioxide dispersion liquid to the zirconium oxychloride in the mixed solution of zirconium oxychloride and aluminum chloride is 2.5:1.

[0091] ② The intermediate, water and a dispersant are added into a stirring kettle, and stirred uniformly to obtain an intermediate dispersion liquid; then a zirconium oxychloride solution is added into the stirring kettle under stirring, and after being stirred uniformly, the pH of the materials in the stirring kettle is adjusted to 9 by using ammonia water, heated to 65℃, and kept for 7 h of reaction; after the reaction is completed, the filter cake is repeatedly washed with distilled water until no chloride ion is detected in the filtrate, and finally washed with anhydrous alcohol, dried, and calcined in a muffle furnace at 550℃ for 3 h to obtain zirconium oxide coated aluminum trioxide; wherein the dispersant is polyethylene glycol phosphate quaternary ammonium salt, the mass of the dispersant is 3% of the mass of the intermediate, and the mass fraction of the intermediate in the intermediate dispersion liquid is 10%; the mass fraction of zirconium oxychloride in the zirconium oxychloride solution is 9%; and the mass ratio of the intermediate in the intermediate dispersion liquid to the zirconium oxychloride in the zirconium oxychloride solution is 6:1. The chemical structure of the polyethylene glycol phosphate quaternary ammonium salt is as follows:

[0092] .

[0093] (10) The dual-curable coating was spray coated on the surface of the marble substrate to form a coating film with a thickness of 100 pm, then the coating film was irradiated for photocuring using ultraviolet light, and then the photocured coating film was hot-pressed using a mirror surface steel plate (Ra of the steel plate ≤ 0.01 pm), and finally the hot-pressed coating film was heat cured to obtain a hot-pressing-assisted dual-cured mirror surface coating; wherein the roughness of the surface of the marble substrate was 1.0 mm; the energy density of the ultraviolet light for photocuring was 300 mJ / cm 2 , and the time was 30 s; the temperature during hot-pressing was 120 °C, the pressure was 4 MPa, and the time was 15 s; the temperature for heat curing was 150 °C, and the time was 30 min.

[0094] Comparative Example 1

[0095] The hot-pressing-assisted dual-cured mirror surface coating of the present comparative example differed from the hot-pressing-assisted dual-cured mirror surface coating of Example 1 only in that the spiroethanedithiol was replaced by 1,6-hexanedithiol in step (6) when the hot-pressing-assisted dual-cured mirror surface coating of the present comparative example was prepared.

[0096] Comparative Example 2

[0097] The hot-pressing-assisted dual-cured mirror surface coating of the present comparative example differed from the hot-pressing-assisted dual-cured mirror surface coating of Example 1 only in that the 5,5-dimethyl-2-(piperazin-1-yl)-4,5-dihydrothiazole was replaced by 1-(2-thiophen-2-yl-ethyl)piperazine in step (3) when the hot-pressing-assisted dual-cured mirror surface coating of the present comparative example was prepared.

[0098] Comparative Example 3

[0099] The hot-pressing-assisted dual-cured mirror surface coating of the present comparative example differed from the hot-pressing-assisted dual-cured mirror surface coating of Example 1 only in that the 5,5-dimethyl-2-(piperazin-1-yl)-4,5-dihydrothiazole was replaced by 1-(1-methyl-1H-imidazol-2-yl)piperazine in step (3) when the hot-pressing-assisted dual-cured mirror surface coating of the present comparative example was prepared.

[0100] Comparative Example 4

[0101] The hot-pressing-assisted dual-cured mirror surface coating of the present comparative example differed from the hot-pressing-assisted dual-cured mirror surface coating of Example 1 only in that the 2-(2,3-epoxypropylthio)thiophene in step (4) was replaced by 1-(oxetan-2-ylmethyl)-1H-1,2,4-triazole when the hot-pressing-assisted dual-cured mirror surface coating of the present comparative example was prepared, and the 1-(oxetan-2-ylmethyl)-1H-1,2,4-triazole in step (5) was replaced by 2-(2,3-epoxypropylthio)thiophene.

[0102] Comparative Example 5

[0103] The hot-pressing assisted double-cured mirror coating of the present comparative example differs from the hot-pressing assisted double-cured mirror coating of Example 1 only in that the amount of the functional ultraviolet light-curable monomer in step (8) during preparation of the present comparative example is 0.

[0104] Comparative Example 6

[0105] The hot-pressing assisted double-cured mirror coating of the present comparative example differs from the hot-pressing assisted double-cured mirror coating of Example 1 only in that the preparation method of the zirconia-coated aluminum trioxide in step (9) during preparation of the present comparative example omits step ① and directly replaces the intermediate in step ② with the nano-aluminum trioxide in step ①.

[0106] Comparative Example 7

[0107] The hot-pressing assisted double-cured mirror coating of the present comparative example differs from the hot-pressing assisted double-cured mirror coating of Example 1 only in that the dispersant in steps ① and ② of the preparation method of the zirconia-coated aluminum trioxide in step (9) during preparation of the present comparative example is dodecyl trimethyl ammonium bromide.

[0108] Comparative Example 8

[0109] The hot-pressing assisted double-cured mirror coating of the present comparative example differs from the hot-pressing assisted double-cured mirror coating of Example 1 only in that the preparation method of the polyethylene glycol phosphate quaternary ammonium salt used in step (9) during preparation of the present comparative example replaces the triisopentyl amine with triamyl amine in step (2).

[0110] Comparative Example 9

[0111] The hot-pressing assisted double-cured mirror coating of the present comparative example differs from the hot-pressing assisted double-cured mirror coating of Example 1 only in that the mass ratio of zirconium oxychloride to aluminum chloride in step ① of the preparation method of the zirconia-coated aluminum trioxide in step (9) during preparation of the present comparative example is 1:4.

[0112] Comparative Example 10

[0113] The hot-pressing assisted double-cured mirror coating of the present comparative example differs from the hot-pressing assisted double-cured mirror coating of Example 1 only in that the mass ratio of zirconium oxychloride to aluminum chloride in step ① of the preparation method of the zirconia-coated aluminum trioxide in step (9) during preparation of the present comparative example is 4:4.

[0114] Experimental Example

[0115] In order to investigate the comprehensive performance of the hot-pressing assisted double-cured mirror coatings of each embodiment and the comparative example, the adhesion, gloss, gloss uniformity, scratch resistance, micro-scratch grade, wear resistance and impact resistance of the hot-pressing assisted double-cured mirror coatings of each embodiment and the comparative example were tested, respectively. Among them, the adhesion test was carried out according to the provisions in the standard ASTM-D-4541 “pull-off adhesion test”; the gloss was measured by a gloss meter, and the measurement angle was 20° during the measurement; the test method of the gloss uniformity was as follows: the gloss of 15 positions on the coating was measured by a gloss meter, then the maximum value of the difference of the gloss of the 15 positions was calculated, and the maximum value represented the gloss uniformity; the test method of the scratch resistance was as follows: 0# steel wool was used to rub back and forth on the surface of the coating at a constant speed, and the number of rubs required for the first obvious scratch on the surface of the coating was used as the evaluation index of the scratch resistance, and a force of 1 kg was applied to the steel wool perpendicular to the surface of the coating during the test; the micro-scratch grade was tested and rated according to the provisions in the standard BS EN 16094-2012 “laminated wood flooring. Micro-scratch determination test method”; the wear resistance was tested by an Akron abrasion tester under the same conditions, and the test result was represented by the abrasion amount; the impact resistance was tested according to the provisions in the standard GB / T1732-1993 “paint film impact resistance determination method”. During the performance test of the hot-pressing assisted double-cured mirror coating, each sample was tested repeatedly for 3 times, and the average value of the test results of the 3 times was used as the final experimental result.

[0116] The test results of the adhesion, gloss, gloss uniformity, scratch resistance, micro-scratch grade, wear resistance and impact resistance of the hot-pressing assisted double-cured mirror coatings of each embodiment and the comparative example are shown in Table 1. The appearance of the hot-pressing assisted double-cured mirror coatings of Example 1 and Comparative Example 1 after the wear resistance test is shown in Figure 6 and Figure 7 .

[0117]

[0118] As shown in Table 1, the functional ultraviolet curing monomer with branched and network structure is synthesized, the flexible dimeric acid structure, rigid triazole ring, rigid thiazole ring, rigid piperazine ring, silicon atom, spiro ring and polyene structure in the molecular chain are utilized, and good adhesion, gloss uniformity, scratch resistance, wear resistance and impact resistance of the coating are obtained. The triazole ring, piperazine ring, spiro ring and thiazole ring in the functional ultraviolet curing monomer can improve the affinity and bonding strength between the inorganic wear-resistant particles in the coating through hydrogen bond and other forces, ensure the uniformity and bonding stability of the inorganic wear-resistant particles in the coating, and further improve the gloss uniformity, wear resistance and impact resistance of the coating. The spiro ring structure in the functional ultraviolet curing monomer can simultaneously impart good flexibility and rigidity to the coating, four double bonds can form good chemical crosslinking with the photocuring resin and monomer in the photocuring stage, further stabilize and confine the wear-resistant particles in the coating, the flexible long fatty chain and the rigid heteroatom ring can avoid the agglomeration of the inorganic wear-resistant particles in the coating on the one hand, and can adjust the rigidity and toughness of the coating on the other hand, so that the coating has high hardness and high toughness, and the wear resistance and impact resistance of the coating are improved.

[0119] In addition, the zirconium oxide coated aluminum trioxide is obtained by first coating the precursor of zirconium oxide and aluminum oxide on the surface of nano-aluminum trioxide as a transition layer, then coating the precursor of zirconium oxide again, and finally calcining, the bonding strength and coating uniformity of zirconium oxide on the surface of aluminum trioxide are improved, and the overall strength and integrity of the zirconium oxide coated aluminum trioxide are improved, so that the zirconium oxide on the surface of the particles does not fall off or break when rubbed and scratched, and the overall performance of the coating is affected. And the polyethylene glycol phosphate quaternary ammonium salt is synthesized, which has a branched structure, contains a large number of quaternary ammonium salt groups, phosphate and alcohol ether structures, has excellent surface activity, can improve the dispersibility of nano-aluminum trioxide, can improve the uniformity of the precursor of zirconium oxide and aluminum oxide, and can promote the precursor to uniformly approach the surface of nano-aluminum trioxide, thereby improving the coating uniformity of the transition layer of zirconium oxide and aluminum oxide and the coating uniformity of the pure zirconium oxide layer, reducing surface defects, and improving the strength and wear resistance of the zirconium oxide coated aluminum trioxide.

[0120] As shown in Example 1 and Comparative Example 1, when the spiro ring structure is absent in the functional ultraviolet curing monomer, the overall performance of the prepared coating deviates, because the spiro ring structure can better cooperate with the long fatty chain and rigid benzene ring, heteroatom ring in the functional ultraviolet curing monomer, impart better hardness and toughness to the coating, and improve the overall performance of the coating. In addition, as shown in Example 1 and Comparative Example 1, Figure 6 and Figure 7 It can be seen that the wear mark of the hot-pressing assisted double curing mirror coating of Example 1 is not obvious after the wear resistance test, while the wear mark of the hot-pressing assisted double curing mirror coating of Comparative Example 1 is more, which again proves that the hot-pressing assisted double curing mirror coating of Example 1 has better wear resistance.

[0121] From Example 1 and Comparative Examples 2-3, it can be seen that the structure of the heteroatom ring grafted at the end of magnolol has an important influence on the performance of the coating, and the thiazole heterocycle can improve the overall performance of the coating better than the thiophene ring and the imidazole ring, and it contains both sulfur and nitrogen atoms, which can improve the affinity and force between the inorganic wear-resistant particles in the coating, thereby improving the coating density and the uniformity of the distribution of wear-resistant particles.

[0122] From Example 1 and Comparative Example 4, it can be seen that the position of the thiophene ring and the triazole ring in the functional ultraviolet light curing monomer also affects the performance of the coating. When the triazole ring is located on the molecular chain of magnolol grafted with a thiazole ring and a piperazine ring, the excessive and dense nitrogen atoms will cause excessive steric hindrance of the magnolol molecular chain, affecting the affinity and compatibility between the magnolol molecular chain and the wear-resistant particles. When the triazole ring is located on the molecular chain of the dimer acid, on the one hand, it can improve the rigidity of the dimer acid molecular chain, and on the other hand, it can improve the bonding strength between the inorganic wear-resistant particles through hydrogen bonding and other action modes, thereby improving the overall performance of the coating.

[0123] From Example 1 and Comparative Example 5, it can be seen that when the functional ultraviolet light curing monomer is not used, the impact resistance of the coating is poor, which is due to the low crosslinking degree of the system, resulting in insufficient coating density, hardness and rigidity, thereby affecting the impact resistance of the coating.

[0124] From Example 1 and Comparative Example 6, it can be seen that when the precursor transition layer of zirconium oxide and aluminum oxide is omitted, due to the difference in surface structure and poor affinity, the uniformity and strength of the zirconium oxide layer coated on the nano-aluminum trioxide surface are defective, resulting in deviation of the overall strength and wear resistance of the coated particles.

[0125] From Example 1 and Comparative Examples 7-8, it can be seen that using a traditional quaternary ammonium salt dispersant or changing the branched structure in the dispersant to a straight chain structure results in poor dispersion effect of the dispersant on the nano-aluminum trioxide and the dispersion effect of the precursor, affecting the quality of the coated layer and leading to deterioration of the performance of the coating.

[0126] From Example 1 and Comparative Examples 9-10, it can be seen that the ratio of the precursors of zirconium oxide and aluminum oxide in the transition layer also affects the overall performance of the coated particles. When the zirconium oxide precursor in the transition layer is too much, the affinity and bonding strength with the inner layer of aluminum oxide are weak; when the aluminum oxide precursor in the transition layer is too much, the affinity and bonding strength with the outer layer of zirconium oxide are weak.

[0127] In summary, the hot-pressing assisted double-curing mirror coating has higher gloss, higher than 92-98GU of the traditional high-gloss wallboard and 90-95GU of the traditional glazed ceramic tile, the micro-scratch level is equivalent to that of the traditional glazed ceramic tile, higher than B5 level of the traditional high-gloss wallboard, the drop ball impact performance is higher than 0.5m of the traditional high-gloss wallboard and the traditional glazed ceramic tile, and the substrate tolerance tolerance (≤1.0mm) is significantly greater than that of the traditional high-gloss wallboard (≤0.2mm) and the traditional glazed ceramic tile (≤0.3mm), which can replace the traditional sintered glaze layer, and can improve the impact resistance, wear resistance and processing stability of the glazed ceramic tile.

[0128] It should be noted that in this paper, the terms: include, contain and any other variants are intended to cover non-exclusive inclusion, so that the process, method, article or device including a series of elements not only includes those elements, but also includes other elements not explicitly listed, or includes elements inherent to such process, method, article or device. The principles and embodiments of the technical solutions of the present application are described by specific examples. The above example is only used to help understand the method of the present application and its core idea. The above is only the preferred embodiment of the present application. It should be pointed out that due to the limitation of language expression, there are infinite specific structures, and for ordinary skilled persons in the art, without departing from the principles of the present application, some improvements, decorations or changes can be made, or the above technical features can be combined in an appropriate way; these improvements, decorations, changes or combinations, or without improvement, directly apply the concept and technical solutions of the present application to other occasions, should be regarded as the protection scope of the present application.

Claims

1. A hot-press-assisted dual-curing mirror coating, characterized in that, The coating is prepared by a dual-curing process. The dual-curing coating mainly comprises a photocurable resin, a photocurable monomer, an epoxy resin, diamond nanosheets, zirconium oxide-coated alumina, and a photoinitiator. The photocurable monomer includes a functional UV-curable monomer. The zirconium oxide-coated alumina is prepared by the following method: first, nano-alumina, water, polyethylene glycol phosphate quaternary ammonium salt, zirconium oxychloride, and aluminum chloride are mixed and reacted to obtain an intermediate; then, the intermediate, water, polyethylene glycol phosphate quaternary ammonium salt, and zirconium oxychloride are mixed and reacted to obtain zirconium oxide-coated alumina. The structure of the functional UV-curable monomer is as follows: ； The structure of the polyethylene glycol phosphate quaternary ammonium salt is as follows: 。 2. The hot-press-assisted dual-curing mirror coating according to claim 1, characterized in that, The diamond nanosheets have an average diameter of 50-80 nm.

3. The hot-press-assisted dual-curing mirror coating according to claim 1, characterized in that, The photocurable monomers also include 2-acrylate-2-[[(butylamino)-carbonyl]oxo]ethyl ester, trimethylolpropane triacrylate, and tripropylene glycol diacrylate.

4. The hot-press-assisted dual-curing mirror coating according to claim 3, characterized in that, The light-curing resin is an aliphatic polyurethane acrylate; the epoxy resin is epoxy resin E51; the dual-curing coating also includes a release agent, which is isooctanol phosphate.

5. The hot-press-assisted dual-curing mirror coating according to claim 4, characterized in that, The photocurable resin and photocurable monomer constitute a photocurable mixture. The mass ratio of the photocurable mixture, epoxy resin, diamond nanosheets, zirconium oxide-coated alumina, photoinitiator, and release agent is 50~60:20~30:5~8:10~15:3~5:0.5~1. The mass ratio of aliphatic polyurethane acrylate, functional UV-curable monomer, 2-acrylate-2-[[(butylamino)-carbonyl]oxo]ethyl ester, trimethylolpropane triacrylate, and tripropylene glycol diacrylate is 27~30:30~35:10~15:7~10:18~20.

6. The hot-press-assisted dual-curing mirror coating according to any one of claims 1-5, characterized in that, The intermediate is prepared as follows: nano-alumina, water and polyethylene glycol phosphate quaternary ammonium salt are mixed to obtain a nano-alumina dispersion; then a mixed solution of zirconium oxychloride and aluminum chloride is added, and the pH of the reaction system is adjusted to 8.5~9 with ammonia water. The reaction is kept at 60~65℃ for 2~3h. After solid-liquid separation, the obtained solid is washed to obtain the intermediate. The mass of polyethylene glycol phosphate quaternary ammonium salt is 1-3% of the mass of nano-alumina, and the mass fraction of nano-alumina in the nano-alumina dispersion is 6-8%; the total mass fraction of zirconium oxychloride and aluminum chloride in the mixed solution is 4-6%, and the mass ratio of zirconium oxychloride to aluminum chloride is 2-3:4-5; the mass ratio of nano-alumina in the nano-alumina dispersion to the mass of zirconium oxychloride in the mixed solution of zirconium oxychloride and aluminum chloride is 1.5-2.5:

1.

7. The hot-press-assisted dual-curing mirror coating according to any one of claims 1-5, characterized in that, The method for preparing zirconia-coated alumina using an intermediate is as follows: The intermediate, water, and polyethylene glycol phosphate quaternary ammonium salt are mixed to obtain an intermediate dispersion; then, a zirconium oxychloride solution is added, and the pH of the reaction system is adjusted to 8.5–9 with ammonia. The reaction is carried out at 60–65°C for 5–7 hours. After solid-liquid separation, the obtained solid is washed, dried, and calcined to obtain zirconia-coated alumina. The mass of polyethylene glycol phosphate quaternary ammonium salt is 1–3% of the mass of the intermediate, and the mass fraction of the intermediate in the intermediate dispersion is 8–10%. The mass fraction of zirconium oxychloride in the zirconium oxychloride solution is 7-9%; the mass ratio of the intermediate dispersion to the zirconium oxychloride in the zirconium oxychloride solution is 4-6:

1.

8. The hot-press-assisted dual-curing mirror coating according to claim 6, characterized in that, The average particle size of the nano-alumina is 10~20nm.

9. A molding process for a hot-press-assisted dual-curing mirror coating as described in any one of claims 1-8, characterized in that, Includes the following steps: A dual-curing coating is applied to the surface of a substrate, and then photocuring, hot pressing, and heat curing are performed sequentially to obtain a hot-press-assisted dual-curing mirror coating.

10. The molding process for the hot-press-assisted dual-curing mirror coating according to claim 9, characterized in that, The UV light energy density of the photocuring process is 200~400 mJ / cm². 2 The time for hot pressing is 20~30s; the temperature for hot pressing is 100~120℃, the pressure is 3~5MPa, and the time is 10~30s; the temperature for heat curing is 140~160℃, and the time is 20~40min.

Images