A highly flexible emulsion, its preparation method, and its application in soft porcelain.

Abstract

This invention belongs to the field of building materials technology, specifically relating to a high-flexibility emulsion, its preparation method, and its application in flexible ceramics. The high-flexibility emulsion uses methyl methacrylate, isooctyl acrylate, hydroxyethyl acrylate, and modifier A as core monomers; and methyl methacrylate, styrene, hydroxyethyl acrylate, and modifier B as shell monomers, prepared using a monomer pre-emulsification semi-continuous seed emulsion polymerization process. Modifier A is obtained by reacting epoxidized cashew nut shell powder with a mercapto compound; modifier B is obtained by reacting carboxybenzotriazole, epoxy silane, and epoxy acrylate. This invention prepares a core-shell structured high-flexibility emulsion using a monomer pre-emulsification semi-continuous seed emulsion polymerization process. By introducing specific modifiers A and B into the core and shell monomers, the low-temperature flexibility, frost resistance, tensile properties, and weather resistance of flexible ceramics are optimized.

Description

Technical Field

[0001] This invention belongs to the field of building materials technology, specifically relating to a highly flexible emulsion, its preparation method, and its application in soft porcelain. Background Technology

[0002] Porcelain is a new type of lightweight building material with advantages such as good flexibility, light weight, thinness, energy saving, and environmental friendliness. It is widely used in interior and exterior wall decoration, floor paving, and other fields, and has become one of the key areas of research and development in the world's green building materials field. Soft porcelain is usually made by mixing water-based resin emulsion with inorganic materials and then going through processes such as molding, drying, and embossing.

[0003] Waterborne resin emulsions are key materials in the molding process of flexible ceramics, playing a decisive role in their performance. However, most of the waterborne resin emulsions used in flexible ceramics currently employ physical blending of commercially available waterborne acrylic resins with low and high glass transition temperatures. While the resulting flexible ceramics exhibit a certain degree of flexibility at room temperature, they remain brittle and hard at low temperatures. Simple physical blending cannot improve the weather resistance and flexibility of flexible ceramics.

[0004] The applicant's previous research results, disclosed in Chinese Patent No. CN 121471648 A, disclose a large-particle-size, highly permeable emulsion for soft porcelain, its preparation method, and its application. This technical solution adopts a layered design with a core-shell structure to achieve complementary performance. At the same time, it uses reactive emulsifiers and functional monomers to improve stability and adhesion. In addition, it adds a polyether polyester block reactive toughening agent and a phosphorus and nitrogen-containing benzisothiazolinone derivative antibacterial flame retardant to achieve synergistic optimization of toughening, antibacterial, and flame retardancy. However, this technical solution can only be adapted to -20℃, and its low-temperature flexibility needs to be improved.

[0005] In view of this, this invention is hereby proposed. Summary of the Invention

[0006] To address the shortcomings mentioned in the background art, the present invention aims to provide a high-flexibility emulsion, its preparation method, and its application in soft porcelain. The present invention prepares a core-shell structured high-flexibility emulsion by employing a monomer pre-emulsification semi-continuous seed emulsion polymerization process. By introducing specific modifying agents A and B into the core layer monomers and shell layer monomers, the low-temperature flexibility, freeze resistance, tensile properties, and weather resistance of soft porcelain are optimized.

[0007] To achieve the above objectives, the present invention provides the following technical solution: The first aspect of this invention provides a highly flexible emulsion, wherein the highly flexible emulsion is prepared by a monomer pre-emulsification semi-continuous seed emulsion polymerization process, wherein methyl methacrylate, isooctyl acrylate, hydroxyethyl acrylate and modifier A are core monomers, and methyl methacrylate, styrene, hydroxyethyl acrylate and modifier B are shell monomers. The modified additive A is obtained by reacting epoxidized cashew nut phenol with a thiol compound; The modified additive B is obtained by reacting carboxybenzotriazole, epoxysilane and epoxy acrylate.

[0008] Preferably, the mass ratio of the core monomer to the shell monomer is 1:1.

[0009] Preferably, the mass ratio of methyl methacrylate, isooctyl acrylate, hydroxyethyl acrylate and modifier A is 30-40:30-40:10-20:10-20.

[0010] Preferably, the modified additive A is prepared by mixing epoxidized cashew phenol, mercapto compound, benzoyl peroxide and ethanol, reacting under nitrogen protection at 50-80℃ for 2-4 hours, washing with water after the reaction, filtering, and distilling under reduced pressure to obtain the product.

[0011] Preferably, the mass ratio of the epoxidized cashew phenol, the mercapto compound, and benzoyl peroxide is 10:3-6:0.05-0.1.

[0012] Preferably, the mass ratio of epoxidized cashew phenol to ethanol is 1:4-6.

[0013] Preferably, the method for preparing the epoxidized cashew phenol is as follows: cashew phenol, epichlorohydrin and benzyltriethylammonium chloride are mixed and reacted at 80-110℃ for 2-4 hours, the temperature is lowered to 60-70℃, sodium hydroxide is added, and the reaction is continued for 3-5 hours. After the reaction is completed, the mixture is washed with water, filtered, and distilled under reduced pressure to obtain the product.

[0014] Preferably, the molar ratio of cashew phenol to epichlorohydrin is 1:6-10.

[0015] Preferably, the amount of benzyltriethylammonium chloride added is 1-2% of the mass of cashew phenol.

[0016] Preferably, the molar ratio of sodium hydroxide to cashew phenol is 1-2:1.

[0017] Preferably, the thiol compound includes thiol silane and 4,4'-dimercaptostilbene.

[0018] Preferably, the mass ratio of the mercaptosilane to 4,4'-dimercaptostilbene is 1:1.

[0019] Preferably, the mercaptosilane is selected from at least one of 3-mercaptopropyltriethoxysilane, 3-mercaptopropyltrimethoxysilane, and 3-mercaptopropylmethyldimethoxysilane.

[0020] Preferably, the mass ratio of methyl methacrylate, styrene, hydroxyethyl acrylate and modifier B is 40-70:10-20:10-20:10-20.

[0021] Preferably, the preparation method of the modified additive B includes the following steps: mixing carboxybenzotriazole, epoxy acrylate, epoxy silane, triphenylphosphine, hydroquinone and acetone, reacting at 70-80℃ for 4-6 hours, and obtaining the product by rotary evaporation after the reaction is completed.

[0022] Preferably, the molar ratio of the carboxybenzotriazole, epoxy acrylate and epoxy silane is 1-1.2:0.4-0.6:0.4-0.6.

[0023] Preferably, the amount of triphenylphosphine added is 0.5-2% of the total mass of carboxybenzotriazole, epoxy acrylate and epoxy silane.

[0024] Preferably, the amount of hydroquinone added is 0.1-1% of the mass of epoxy acrylate.

[0025] Preferably, the amount of acetone added is 40-50% of the total mass of carboxybenzotriazole and epoxy acrylate.

[0026] Preferably, the carboxybenzotriazole is selected from at least one of 5-carboxybenzotriazole and 4-carboxybenzotriazole.

[0027] Preferably, the epoxy acrylate is selected from at least one of glycidyl methacrylate and glycidyl acrylate.

[0028] Preferably, the epoxy silane is selected from γ-glycidoxypropyltriethoxysilane and γ-glycidoxypropyltrimethoxysilane.

[0029] A second aspect of the present invention provides a method for preparing a highly flexible emulsion, comprising the following steps: S1. Preparation of core layer preemulsion: Dissolve 0.5-3 parts of emulsifier in 10-30 parts of deionized water, add 100 parts of core layer monomer while stirring, and stir to obtain core layer preemulsion; S2. Preparation of shell preemulsion: Dissolve 0.5-3 parts of emulsifier in 10-30 parts of deionized water, add 100 parts of shell monomer while stirring, and stir to obtain shell preemulsion; S3. Preparation of a highly flexible emulsion core layer: Dissolve 0.5-3 parts of emulsifier in 90-150 parts of deionized water, heat, add 10-20% of the core layer pre-emulsion, 0.5-5 parts of initiator and 5-15 parts of deionized water, and keep the reaction at the specified temperature to obtain a seed emulsion; add the remaining core layer pre-emulsion, 0.5-5 parts of initiator and 5-15 parts of deionized water dropwise, and keep the reaction at the specified temperature after the addition is complete to obtain a highly flexible emulsion core layer; S4. Preparation of high-flexibility emulsion: Add shell pre-emulsion, 0.5-5 parts initiator and 5-15 parts deionized water dropwise to the core layer of the high-flexibility emulsion. After the addition is complete, keep the reaction at a constant temperature. Finally, add a neutralizing agent to adjust the pH to 6-8 and filter to obtain the emulsion.

[0030] Preferably, S1 specifically involves dissolving 0.5-3 parts of emulsifier in 10-30 parts of deionized water, adding 100 parts of core layer monomer while stirring, and stirring for 30-60 minutes to obtain a core layer pre-emulsion.

[0031] Preferably, S2 specifically involves dissolving 0.5-3 parts of emulsifier in 10-30 parts of deionized water, adding 100 parts of shell monomer while stirring, and stirring for 30-60 minutes to obtain a shell pre-emulsion.

[0032] Preferably, S3 specifically involves: dissolving 0.5-3 parts of emulsifier in 90-150 parts of deionized water, heating to 70-90°C, adding 10-20% of the core layer pre-emulsion, 0.5-5 parts of initiator, and 5-15 parts of deionized water, and maintaining the temperature for 30 minutes to obtain a seed emulsion; then adding the remaining core layer pre-emulsion, 0.5-5 parts of initiator, and 5-15 parts of deionized water dropwise over 1-2 hours, and maintaining the temperature for 30-60 minutes after the addition to obtain a highly flexible emulsion core layer.

[0033] Preferably, S4 specifically involves: adding a shell pre-emulsion, 0.5-5 parts of initiator, and 5-15 parts of deionized water dropwise to the core layer of the highly flexible emulsion, completing the dropwise addition in 1-2 hours, and maintaining the temperature for 0.5-2 hours after the dropwise addition is completed; finally, adding a neutralizing agent to adjust the pH to 6-8 and filtering to obtain the final product.

[0034] Preferably, the initiator is selected from at least one of sodium persulfate, ammonium persulfate, and potassium persulfate.

[0035] Preferably, the emulsifier is selected from at least one of sodium dodecyl sulfate, sodium dodecyl diphenyl ether disulfonate, isotridecyl alcohol polyoxyethylene ether, sodium allyl ether hydroxypropyl sulfonate, and allyloxy fatty alcohol polyoxyethylene ether.

[0036] Preferably, the neutralizing agent is selected from at least one of triethylamine, triethanolamine, and ammonia.

[0037] A third aspect of the present invention provides the application of a highly flexible emulsion in soft porcelain.

[0038] Compared with the prior art, the advantages and beneficial effects of the present invention are as follows: 1. The modified additive A provided by the present invention is obtained by ring-opening reaction of the epoxy group in the epoxidized cashew phenol and the mercapto group in the mercapto compound. The mercapto compound includes mercaptosilane and 4,4'-dimercaptostilbene. The modified additive A introduces siloxane segments and thioether bonds, and also contains polymerizable double bonds. Using it as a core layer monomer, it significantly improves the low-temperature flexibility and freeze resistance of soft porcelain.

[0039] 2. The modified additive B of the present invention is obtained by ring-opening reaction of the carboxyl group in carboxybenzotriazole and the epoxy group in epoxy acrylate and epoxy silane. The modified additive B introduces siloxane segments and benzotriazole structure, and contains polymerizable double bonds. It is used as a shell monomer. When it works together with the modified additive A in the core monomer, it not only significantly improves the low-temperature flexibility and freeze resistance of soft porcelain, but also significantly improves the weather resistance of soft porcelain.

[0040] 3. The high flexibility emulsion provided by this invention enables soft porcelain to maintain excellent flexibility at -30℃, and can withstand 100 repeated freeze-thaw cycles between -30℃ and 10℃ without cracking or peeling; the weather resistance reaches 3500h, which is equivalent to not deteriorating for 50 years. Detailed Implementation

[0041] The technical solutions in the embodiments of the present invention will be clearly and completely described below. Obviously, the described embodiments are only some embodiments of the present invention, and not all embodiments. Based on the embodiments of the present invention, all other embodiments obtained by those skilled in the art without creative effort are within the scope of protection of the present invention.

[0042] Preparation Example 1 Preparation of Modifying Agent A: Mix 10 parts of epoxidized cashew phenol, 5 parts of mercapto compound, 0.08 parts of benzoyl peroxide and 50 parts of ethanol, and react at 70°C for 3 hours under nitrogen protection. After the reaction is completed, wash with water, filter, and distill under reduced pressure to obtain the product.

[0043] The thiol compound is 3-mercaptopropyltriethoxysilane and 4,4'-dimercaptostilbene in a mass ratio of 1:1.

[0044] The method for preparing the epoxidized cashew phenol is as follows: Cashew phenol and epichlorohydrin are mixed in a molar ratio of 1:8, and benzyltriethylammonium chloride (2% of the mass of cashew phenol) is added. The mixture is reacted at 110°C for 3 hours, cooled to 60°C, and sodium hydroxide of the same molar amount as cashew phenol is added. The reaction is continued for 3 hours. After the reaction is completed, the mixture is washed with water, filtered, and distilled under reduced pressure to obtain the product.

[0045] Preparation Example 2 Preparation of Modifying Agent B: 5-Carboxybenzotriazole, glycidyl methacrylate, and γ-glycidyl etheroxypropyltriethoxysilane were mixed in a molar ratio of 1.2:0.5:0.5. Triphenylphosphine, hydroquinone, and acetone were added, and the mixture was reacted at 75°C for 5 hours. After the reaction was completed, the mixture was obtained by rotary evaporation.

[0046] The amount of triphenylphosphine added is 1% of the total mass of 5-carboxybenzotriazole, glycidyl methacrylate, and γ-glycidyl etheroxypropyltriethoxysilane.

[0047] The amount of hydroquinone added is 0.5% of the mass of glycidyl methacrylate.

[0048] The amount of acetone added is 50% of the total mass of 5-carboxybenzotriazole and γ-glycidyl etheroxypropyltriethoxysilane.

[0049] Example 1 A highly flexible emulsion, prepared by the following method: S1. Preparation of core layer preemulsion: Dissolve 0.8 parts of sodium dodecyl sulfate in 30 parts of deionized water, add 100 parts of core layer monomer while stirring, stir for 60 min to obtain core layer preemulsion; S2. Preparation of shell preemulsion: Dissolve 0.8 parts of sodium dodecyl sulfate in 30 parts of deionized water, add 100 parts of shell monomer while stirring, stir for 60 min to obtain shell preemulsion; S3. Preparation of a highly flexible emulsion core layer: Dissolve 0.8 parts of sodium dodecyl sulfate in 120 parts of deionized water, heat to 80°C, add 20% of the core layer pre-emulsion, 0.8 parts of sodium persulfate and 10 parts of deionized water, and keep the reaction at this temperature for 30 min to obtain a seed emulsion; add the remaining core layer pre-emulsion, 0.6 parts of sodium persulfate and 10 parts of deionized water dropwise, completing the addition in 2 h, and keep the reaction at this temperature for 30 min after the addition is complete to obtain a highly flexible emulsion core layer; S4. Preparation of high-flexibility emulsion: Add shell pre-emulsion, 0.6 parts sodium persulfate and 10 parts deionized water dropwise to the core layer of the high-flexibility emulsion. The addition is completed in 2 hours. After the addition is completed, keep the reaction at the temperature for 0.5 hours. Finally, add ammonia water to adjust the pH to 7 and filter to obtain the emulsion.

[0050] The core layer monomers are methyl methacrylate, isooctyl acrylate, hydroxyethyl acrylate, and the modifying agent A of Preparation Example 1, in a mass ratio of 30:40:15:15.

[0051] The shell monomers are methyl methacrylate, styrene, hydroxyethyl acrylate and the modifying agent B of Preparation Example 2, in a mass ratio of 60:10:15:15.

[0052] Example 2 A highly flexible emulsion, prepared by the following method: S1. Preparation of core layer preemulsion: Dissolve 0.8 parts of sodium dodecyl sulfate in 30 parts of deionized water, add 100 parts of core layer monomer while stirring, stir for 60 min to obtain core layer preemulsion; S2. Preparation of shell preemulsion: Dissolve 0.8 parts of sodium dodecyl sulfate in 30 parts of deionized water, add 100 parts of shell monomer while stirring, stir for 60 min to obtain shell preemulsion; S3. Preparation of a highly flexible emulsion core layer: Dissolve 0.8 parts of sodium dodecyl sulfate in 120 parts of deionized water, heat to 80°C, add 20% of the core layer pre-emulsion, 0.8 parts of sodium persulfate and 10 parts of deionized water, and keep the reaction at this temperature for 30 min to obtain a seed emulsion; add the remaining core layer pre-emulsion, 0.6 parts of sodium persulfate and 10 parts of deionized water dropwise, completing the addition in 2 h, and keep the reaction at this temperature for 30 min after the addition is complete to obtain a highly flexible emulsion core layer; S4. Preparation of high-flexibility emulsion: Add shell pre-emulsion, 0.6 parts sodium persulfate and 10 parts deionized water dropwise to the core layer of the high-flexibility emulsion. The addition is completed in 2 hours. After the addition is completed, keep the reaction at the temperature for 0.5 hours. Finally, add ammonia water to adjust the pH to 7 and filter to obtain the emulsion.

[0053] The core layer monomers are methyl methacrylate, isooctyl acrylate, hydroxyethyl acrylate, and the modifying agent A of Preparation Example 1, in a mass ratio of 40:30:20:10.

[0054] The shell monomers are methyl methacrylate, styrene, hydroxyethyl acrylate and the modifying agent B of Preparation Example 2, in a mass ratio of 70:10:10:10.

[0055] Example 3 A highly flexible emulsion, prepared by the following method: S1. Preparation of core layer preemulsion: Dissolve 0.8 parts of sodium dodecyl sulfate in 30 parts of deionized water, add 100 parts of core layer monomer while stirring, stir for 60 min to obtain core layer preemulsion; S2. Preparation of shell preemulsion: Dissolve 0.8 parts of sodium dodecyl sulfate in 30 parts of deionized water, add 100 parts of shell monomer while stirring, stir for 60 min to obtain shell preemulsion; S3. Preparation of a highly flexible emulsion core layer: Dissolve 0.8 parts of sodium dodecyl sulfate in 120 parts of deionized water, heat to 80°C, add 20% of the core layer pre-emulsion, 0.8 parts of sodium persulfate and 10 parts of deionized water, and keep the reaction at this temperature for 30 min to obtain a seed emulsion; add the remaining core layer pre-emulsion, 0.6 parts of sodium persulfate and 10 parts of deionized water dropwise, completing the addition in 2 h, and keep the reaction at this temperature for 30 min after the addition is complete to obtain a highly flexible emulsion core layer; S4. Preparation of high-flexibility emulsion: Add shell pre-emulsion, 0.6 parts sodium persulfate and 10 parts deionized water dropwise to the core layer of the high-flexibility emulsion. The addition is completed in 2 hours. After the addition is completed, keep the reaction at the temperature for 0.5 hours. Finally, add ammonia water to adjust the pH to 7 and filter to obtain the emulsion.

[0056] The core layer monomers are methyl methacrylate, isooctyl acrylate, hydroxyethyl acrylate, and the modifying agent A of Preparation Example 1, in a mass ratio of 35:35:10:20.

[0057] The shell monomers are methyl methacrylate, styrene, hydroxyethyl acrylate and the modifying agent B of Preparation Example 2, in a mass ratio of 40:20:20:20.

[0058] Comparative Example 1 The difference between this comparative example and Example 1 is that the core layer monomers are methyl methacrylate, isooctyl acrylate, hydroxyethyl acrylate and the modifying agent B of Preparation Example 2 in a mass ratio of 30:40:15:15.

[0059] The shell monomers are methyl methacrylate, styrene, hydroxyethyl acrylate and the modifying agent A of Preparation Example 1 in a mass ratio of 60:10:15:15; all other components are the same.

[0060] Comparative Example 2 The difference between this comparative example and Example 1 is that the core layer monomers are methyl methacrylate, isooctyl acrylate, and hydroxyethyl acrylate in a mass ratio of 30:40:30.

[0061] The shell monomers are methyl methacrylate, styrene, hydroxyethyl acrylate and the modifying agent B of Preparation Example 2 in a mass ratio of 60:10:15:15; all other components are the same.

[0062] Comparative Example 3 The difference between this comparative example and Example 1 is that the core layer monomers are methyl methacrylate, isooctyl acrylate, hydroxyethyl acrylate and the modifying agent A of Preparation Example 1 in a mass ratio of 30:40:15:15.

[0063] The shell monomers are methyl methacrylate, styrene, and hydroxyethyl acrylate in a mass ratio of 60:10:30; all other components are the same.

[0064] Comparative Example 4 The difference between this comparative example and Example 1 is as follows: the preparation method of the modified additive A is as follows: 10 parts of epoxidized cashew phenol, 5 parts of mercapto compound, 0.08 parts of benzoyl peroxide and 50 parts of ethanol are mixed and reacted at 70°C for 3 hours under nitrogen protection. After the reaction is completed, the mixture is washed with water, filtered, and distilled under reduced pressure to obtain the product. The mercapto compound is 4,4'-dimercaptostilbene. All other aspects are the same.

[0065] Comparative Example 5 The difference between this comparative example and Example 1 is as follows: the preparation method of the modified additive A is as follows: 10 parts of epoxidized cashew phenol, 5 parts of mercapto compound, 0.08 parts of benzoyl peroxide and 50 parts of ethanol are mixed and reacted at 70°C for 3 hours under nitrogen protection. After the reaction is completed, the mixture is washed with water, filtered, and distilled under reduced pressure to obtain the product. The mercapto compound is 3-mercaptopropyltriethoxysilane. All other aspects are the same.

[0066] Comparative Example 6 The difference between this comparative example and Example 1 is that the modifying agent A is replaced with epoxidized cashew nut phenol; all other aspects are the same.

[0067] Comparative Example 7 The difference between this comparative example and Example 1 is as follows: the preparation method of the modified additive B is as follows: citric acid, glycidyl methacrylate, and γ-glycidyl etheroxypropyltriethoxysilane are mixed in a molar ratio of 1.2:0.5:0.5, and triphenylphosphine, hydroquinone, and acetone are added. The mixture is reacted at 75°C for 5 hours. After the reaction is completed, it is obtained by rotary evaporation.

[0068] The amount of triphenylphosphine added is 1% of the total mass of citric acid, glycidyl methacrylate, and γ-glycidyl etheroxypropyltriethoxysilane.

[0069] The amount of hydroquinone added is 0.5% of the mass of glycidyl methacrylate.

[0070] The amount of acetone added is 50% of the total mass of citric acid and γ-glycidoxypropyltriethoxysilane; all other aspects are the same.

[0071] Performance testing A highly flexible emulsion was mixed with 60-mesh quartz sand powder at a ratio of 1:3 to prepare soft porcelain. After molding, it was dried in an oven at 100℃, and the following performance tests were conducted: 1. Low-temperature flexibility: According to GB / T 6742-2007, after freezing at -30℃ for 2 hours, bend a 50mm diameter cylinder and observe the cracks; test the impact strength using the falling ball impact method (1kg steel ball, dropped freely from a height of 1m). 2. Freeze-thaw resistance: Refer to GB / T 3810.12-2016: Cycle between -30℃ and 10℃ for 100 cycles, and observe whether cracks or peeling appear on the surface.

[0072] 3. Tensile properties: Refer to GB / T528-2009, dumbbell-shaped specimen (gauge length 25mm), tensile rate 50mm / min, and measure the tensile strength at room temperature; 4. Weather resistance: Refer to GB / T 16259-2008, the test time is 3500h, and observe whether cracks or powdering appear on the appearance.

[0073]

[0074] Results analysis: Comparative Example 1 shows that modifier A and modifier B cannot be substituted for each other, otherwise it will lead to a decrease in the low-temperature flexibility, frost resistance, tensile properties and weather resistance of soft porcelain.

[0075] Comparative Examples 2 and 3 show that the lack of modifier A or modifier B leads to a decrease in the low-temperature flexibility and frost resistance of soft porcelain, and the two have a synergistic effect; the lack of modifier B also leads to a decrease in the weather resistance of soft porcelain.

[0076] Comparative Examples 4-6 show that both mercaptosilane and 4,4'-dimercaptostilbene in the modifier A are indispensable; otherwise, it will lead to a decrease in the low-temperature flexibility and frost resistance of soft porcelain.

[0077] Comparative Example 7 shows that 5-carboxybenzotriazole cannot be replaced with conventional carboxylic acids, otherwise the weather resistance of soft porcelain will decrease.

[0078] The above description represents the preferred embodiments of the present invention. It should be noted that those skilled in the art can make various improvements and modifications without departing from the principles of the present invention, and these improvements and modifications should also be considered within the scope of protection of the present invention.

Claims

1. A highly flexible emulsion, characterized in that, The highly flexible emulsion is prepared using methyl methacrylate, isooctyl acrylate, hydroxyethyl acrylate and modifier A as core monomers, and methyl methacrylate, styrene, hydroxyethyl acrylate and modifier B as shell monomers, through a monomer pre-emulsification semi-continuous seed emulsion polymerization process. The modified additive A is obtained by reacting epoxidized cashew nut phenol with a thiol compound; The modified additive B is obtained by reacting carboxybenzotriazole, epoxysilane and epoxy acrylate.

2. The high-flexibility emulsion according to claim 1, characterized in that, The mass ratio of methyl methacrylate, isooctyl acrylate, hydroxyethyl acrylate and modifier A is 30-40:30-40:10-20:10-20; the mass ratio of methyl methacrylate, styrene, hydroxyethyl acrylate and modifier B is 40-70:10-20:10-20:10-20.

3. The high-flexibility emulsion according to claim 1 or 2, characterized in that, The modified additive A is prepared by mixing epoxidized cashew phenol, mercapto compound, benzoyl peroxide and ethanol, reacting under nitrogen protection at 50-80℃ for 2-4 hours, washing with water after the reaction, filtering, and distilling under reduced pressure to obtain the product.

4. The high-flexibility emulsion according to claim 3, characterized in that, The method for preparing the epoxidized cashew phenol is as follows: Cashew phenol, epichlorohydrin and benzyltriethylammonium chloride are mixed and reacted at 80-110℃ for 2-4 hours. The temperature is then lowered to 60-70℃, sodium hydroxide is added, and the reaction continues for 3-5 hours. After the reaction is completed, the mixture is washed with water, filtered, and distilled under reduced pressure to obtain the product.

5. The high-flexibility emulsion according to claim 3, characterized in that, The thiol compounds include thiol silanes and 4,4'-dimercaptostilbene.

6. The high-flexibility emulsion according to claim 1 or 2, characterized in that, The preparation method of the modified additive B includes the following steps: mixing carboxybenzotriazole, epoxy acrylate, epoxy silane, triphenylphosphine, hydroquinone and acetone, reacting at 70-80℃ for 4-6 hours, and then rotary evaporating after the reaction is completed to obtain the additive.

7. The high-flexibility emulsion according to claim 6, characterized in that, The carboxybenzotriazole is selected from at least one of 5-carboxybenzotriazole and 4-carboxybenzotriazole.

8. The high-flexibility emulsion according to claim 6, characterized in that, The epoxy acrylate is selected from at least one of glycidyl methacrylate and glycidyl acrylate; the epoxy silane is selected from one of γ-glycidyl etheroxypropyltriethoxysilane and γ-glycidyl etheroxypropyltrimethoxysilane.

9. A method for preparing the highly flexible emulsion according to any one of claims 1-8, characterized in that, Includes the following steps: S1. Preparation of core layer preemulsion: Dissolve 0.5-3 parts of emulsifier in 10-30 parts of deionized water, add 100 parts of core layer monomer while stirring, and stir to obtain core layer preemulsion; S2. Preparation of shell preemulsion: Dissolve 0.5-3 parts of emulsifier in 10-30 parts of deionized water, add 100 parts of shell monomer while stirring, and stir to obtain shell preemulsion; S3. Preparation of a highly flexible emulsion core layer: Dissolve 0.5-3 parts of emulsifier in 90-150 parts of deionized water, heat, add 10-20% of the core layer pre-emulsion, 0.5-5 parts of initiator and 5-15 parts of deionized water, and keep the reaction at the specified temperature to obtain a seed emulsion; add the remaining core layer pre-emulsion, 0.5-5 parts of initiator and 5-15 parts of deionized water dropwise, and keep the reaction at the specified temperature after the addition is complete to obtain a highly flexible emulsion core layer; S4. Preparation of high-flexibility emulsion: Add shell pre-emulsion, 0.5-5 parts initiator and 5-15 parts deionized water dropwise to the core layer of the high-flexibility emulsion. After the addition is complete, keep the reaction at a constant temperature. Finally, add a neutralizing agent to adjust the pH to 6-8 and filter to obtain the emulsion.

10. The application of the high flexibility emulsion according to any one of claims 1-8 in soft porcelain.

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