Copolymer coating wetting dispersant and preparation method thereof

Abstract

The invention relates to a copolymer coating wetting dispersant and a preparation method thereof. The copolymer coating wetting dispersant comprises the following raw materials in parts by weight: 15-25 parts of acrylic acid, 15-20 parts of methyl methacrylate, 10-18 parts of maleic anhydride, 2-3 parts of white carbon black, 2-3 parts of an initiator and 15-20 parts of modified zeolite. Monomethacrylate in the copolymer coating wetting dispersant is polymerized with acrylic acid and maleic anhydride to obtain a copolymer, an active group ester group on a main chain of the copolymer has relatively strong polarity and can be anchored on coating particles, and carboxyl on the copolymer has relatively strong hydrophilicity and stretches in water to form three-dimensional adsorption on the surface of the coating, so that the coating wetting dispersant has a good wetting effect on the coating. Therefore, the coating particles are dispersed and stabilized.

Description

Technical Field

[0001] The invention belongs to the technical field of coating additives, and particularly relates to a copolymer coating wetting dispersant and a preparation method thereof. Background Art

[0002] Fire is the most likely disaster among all natural and social disasters, posing a serious threat to human life and even life safety. At present, a large number of combustible and flammable materials are closely related to our production and life, which increases the potential risk of fire. It is effective to use flame-retardant materials or convert existing combustible materials into flame-retardant or non-combustible materials. At present, coatings are generally flame-retardant by adding flame-retardant fillers. Common flame-retardant fillers include organic flame retardants and inorganic flame retardants; inorganic flame retardants such as aluminum hydroxide and magnesium hydroxide have high surface energy and are difficult to disperse in the base material; organic flame retardants such as triphenyl phosphate and tricresyl phosphate are volatile and will cause potential dangers to the environment and human health when entering the environment.

[0003] Wetting dispersant is a surfactant, and its main function is to reduce the interfacial tension of various coatings during the wetting process of the coating and improve the dispersion efficiency. The invention patent with application publication number CN112898504A discloses a method for preparing a coating dispersant and a coating dispersant, and the preparation method of the coating dispersant includes: synthesizing a polyether alcohol head and a cyclic monomer into a polyether under the action of a catalyst; reacting the polyether with an acid substance under the action of a reducing agent, an initiator, and a chain transfer agent to obtain a polyether dispersant; and adding a neutralizing agent to the polyether dispersant to obtain a coating dispersant, wherein the polyether alcohol head is trans-4,4-dimethoxy-2-butenol, the cyclic monomer is ethylene oxide and propylene oxide, and the acid substance is acrylic acid. The coating dispersant has high dispersibility, but the coating dispersant does not have the ability to help the coating resist high temperatures. Summary of the invention

[0004] The first object of the present invention is to provide a copolymer coating wetting and dispersing agent to solve the technical problem that the existing wetting and dispersing agents cannot solve the coating's inability to withstand high temperatures.

[0005] The second object of the present invention is to provide a method for preparing a copolymer coating wetting and dispersing agent.

[0006] In order to achieve the above purpose, the technical solution adopted by the present invention is: The copolymer coating wetting dispersant comprises the following raw materials in parts by weight: 15-25 parts of acrylic acid, 15-20 parts of methyl methacrylate, 10-18 parts of maleic anhydride, 2-3 parts of white carbon black, 2-3 parts of initiator and 15-20 parts of modified zeolite.

[0007] Furthermore, the preparation method of the modified zeolite is: after shaking the zeolite in a silicate solution, trimethylsilanol is added, heating under acidic conditions for reaction, filtering to obtain a filter cake, and freeze-drying the filter cake to obtain the modified zeolite.

[0008] Furthermore, the mass ratio of the zeolite to the trimethylsilanol is 1:1-1:3.

[0009] Furthermore, the silicate is lithium silicate or potassium silicate.

[0010] Furthermore, the heating temperature is 60-100°C and the reaction time is 3-5 h.

[0011] Furthermore, the mesh size of the zeolite is 40-70 meshes.

[0012] Furthermore, the initiator is one or more of ammonium persulfate, potassium persulfate, and sodium persulfate.

[0013] The preparation method of the copolymer coating wetting dispersant comprises the following steps: 1) dissolving the coupling agent in ethanol to obtain a mixed solution, mixing the modified zeolite with the mixed solution, and then performing ultrasonic dispersion and drying; 2) The dried modified zeolite, methyl methacrylate, 0.02-0.2 parts of initiator and water are reacted at 70-90 °C for 1-5 h, and then acrylic acid and maleic anhydride are added and mixed evenly. After cooling, a neutralizing agent is added dropwise to adjust the pH to 6-8; 3) Raise the temperature to 60-90 °C, add the remaining amount of initiator and white carbon black and continue to react for 3-5 hours to obtain the product.

[0014] Furthermore, the coupling agent is one or more of a titanate coupling agent and an aluminate coupling agent.

[0015] Furthermore, the cooling temperature in step 2) is 30-50° C.; the neutralizing agent is sodium hydroxide solution, and the mass fraction of the sodium hydroxide solution is 25-35%.

[0016] Beneficial effects of the present invention: The copolymer is obtained by polymerizing the monomethacrylate with acrylic acid and maleic anhydride in the copolymer coating wetting dispersant of the present invention. The active ester group on the main chain of the copolymer has strong polarity and can be anchored on the coating particles, while the carboxyl group on the copolymer has strong hydrophilicity and stretches in water to form three-dimensional adsorption on the coating surface, thereby dispersing and stabilizing the coating particles.

[0017] The copolymer coating wetting dispersant of the present invention adds modified zeolite, which has a large number of pores and a large specific surface area inside. These structures can effectively absorb sound waves and reduce noise; at the same time, they can absorb indoor formaldehyde and benzene to improve indoor air quality. In addition, the white carbon black added to the copolymer coating wetting dispersant of the present invention can improve the dispersion effect and dispersion speed.

[0018] The zeolite of the present invention first undergoes a dehydration condensation reaction with trimethylsilanol to generate a Si-O-Si bond, and the bond energy of the Si-O-Si bond is extremely large, which helps to increase the high temperature resistance of the copolymer coating wetting dispersant, so that the copolymer coating wetting dispersant of the present invention can be used in places with high temperatures such as factories. Under the action of an initiator, the modified zeolite and methyl methacrylate are grafted onto the modified zeolite to avoid the problems of high surface energy of the modified zeolite, easy agglomeration, uneven dispersion of the modified zeolite, and weak binding force with the base material. BRIEF DESCRIPTION OF THE DRAWINGS

[0019] Figure 1 This is a diagram showing the delamination of the coatings to which the copolymer coating wetting and dispersing agents in Example 1 and Comparative Example 1 are added after standing for one month; Figure 2 This is a performance diagram of high temperature resistance test of coatings to which the copolymer coating wetting and dispersing agent in Example 1 and Comparative Example 2 is added. DETAILED DESCRIPTION

[0020] The present invention will be further described below in conjunction with the embodiments of the present invention and the accompanying drawings. Example

[0021] The preparation method of the copolymer coating wetting dispersant of Example 1 comprises the following steps: 20 kg of zeolite was placed in a sodium silicate solution, and filtered after ultrasonic oscillation to obtain a filter residue. The filter residue was mixed with 30 kg of trimethylsilanol, and 1 kg of a 95% hydrochloric acid solution was added dropwise. The temperature was raised to 70 °C and reacted for 4 h. The filter residue was then freeze-dried to obtain the modified zeolite. The titanate coupling agent is dissolved in ethanol to obtain a mixed solution, the modified zeolite is mixed with the mixed solution, and then ultrasonically dispersed at 55°C for 1.5 h, and then dried; Take 15 kg of dry modified zeolite, 20 kg of methyl methacrylate, 0.2 kg of potassium persulfate, and 70 kg of water and react at 70 °C for 4 h, then add 20 kg of acrylic acid and 10 kg of maleic anhydride, and add 30% sodium hydroxide solution at 35 °C to adjust the pH to 6; Raise the temperature to 70 °C, add 1.8 kg of potassium persulfate and 2 kg of white carbon black, react for 4 h, cool down and discharge the material.

[0022] The mesh number of zeolite is 50 mesh. Example

[0023] The preparation method of the copolymer coating wetting dispersant of Example 2 comprises the following steps: 1) 25 kg of zeolite was placed in a lithium silicate solution, and then filtered after ultrasonic oscillation to obtain a filter residue. The filter residue was mixed with 30 kg of trimethylsilanol, and 1 kg of a 95% hydrochloric acid solution was added dropwise. The temperature was raised to 100 °C for reaction for 3 h, and then filtered. The filter residue was freeze-dried to obtain a modified zeolite. 2) dissolving the aluminate coupling agent in ethanol to obtain a mixed solution, mixing the modified zeolite with the mixed solution, and then ultrasonically dispersing the mixture at 60° C. for 1 h, followed by drying; 3) Take 18 kg of dry modified zeolite, 22 kg of methyl methacrylate, 0.3 kg of potassium persulfate, and 80 kg of water and react at 80 °C for 4 h, then add 18 kg of acrylic acid and 15 kg of maleic anhydride, and add 25% sodium hydroxide solution at 40 °C to adjust the pH to 6; 4) Raise the temperature to 90 °C, add 2 kg of potassium persulfate and 2.5 kg of white carbon black, react for 3 h, cool down and discharge the material.

[0024] The mesh number of zeolite is 40 mesh. Example

[0025] The preparation method of the copolymer coating wetting dispersant of Example 3 comprises the following steps: 22 kg of zeolite was placed in a sodium silicate solution, and filtered after ultrasonic oscillation to obtain a filter residue. The filter residue was mixed with 35 kg of trimethylsilanol, and 1.5 kg of a 95% hydrochloric acid solution was added dropwise. The temperature was raised to 60 °C for reaction for 5 h, and then filtered. The filter residue was freeze-dried to obtain a modified zeolite. The titanate coupling agent is dissolved in ethanol to obtain a mixed solution, the modified zeolite is mixed with the mixed solution, and then ultrasonically dispersed at 50°C for 2 h, and then dried; Take 20 kg of dry modified zeolite, 25 kg of methyl methacrylate, 0.3 kg of sodium persulfate, and 90 kg of water and react at 90 °C for 2 h, then add 25 kg of acrylic acid and 18 kg of maleic anhydride, and add 50% sodium hydroxide solution at 50 °C to adjust the pH to 8; Raise the temperature to 60 °C, add 2 kg of potassium persulfate and 3 kg of white carbon black, react for 5 h, cool down and discharge the material.

[0026] The mesh number of zeolite is 70 mesh.

[0027] Comparative Example 1 The preparation method of the copolymer coating wetting dispersant of Comparative Example 1 comprises the following steps: 1) 20 kg of zeolite was placed in a sodium silicate solution, and filtered after ultrasonic oscillation to obtain a filter residue. The filter residue was mixed with 30 kg of trimethylsilanol, and 1 kg of a 95% hydrochloric acid solution was added dropwise. The temperature was raised to 70 °C for reaction for 4 h, and then filtered. The filter residue was freeze-dried to obtain the modified zeolite. 2) dissolving the titanate coupling agent in ethanol to obtain a mixed solution, mixing the modified zeolite with the mixed solution, and then ultrasonically dispersing the mixture at 55° C. for 1.5 h, followed by drying; 3) Take 15 kg of dry modified zeolite, 10 kg of methyl methacrylate, 0.1 kg of potassium persulfate, and 40 kg of water and react at 70 °C for 4 h, then add 15 kg of acrylic acid and 10 kg of maleic anhydride, and add 30% sodium hydroxide solution at 35 °C to adjust the pH to 6; 4) Raise the temperature to 70 °C, add 1.1 kg of potassium persulfate and 1.5 kg of white carbon black, react for 4 h, cool down and discharge the material.

[0028] The mesh number of zeolite is 50 mesh.

[0029] Comparative Example 2 The preparation method of the copolymer coating wetting dispersant of Comparative Example 2 comprises the following steps: The titanate coupling agent was dissolved in ethanol to obtain a mixed solution, the zeolite was mixed with the mixed solution, and then ultrasonically dispersed at 55 °C for 1.5 h, and then dried; Take 15 kg of dry zeolite, 20 kg of methyl methacrylate, 0.2 kg of potassium persulfate, and 70 kg of water and react at 70 °C for 4 h, then add 20 kg of acrylic acid and 10 kg of maleic anhydride, and add 30% sodium hydroxide solution at 35 °C to adjust the pH to 6; Raise the temperature to 70 °C, add 1.8 kg of potassium persulfate and 2 kg of white carbon black, react for 4 h, cool down and discharge the material.

[0030] The mesh number of zeolite is 50 mesh.

[0031] The same mass of copolymer coating wetting and dispersing agent of Examples 1-3 and Comparative Example 2 was added to the coating system to test the high temperature resistance and flame retardancy of the coating system. The coating system includes 10 kg of propylene emulsion, 10 kg of calcium carbonate, 6 kg of titanium dioxide, 6 kg of calcined kaolin, 8 kg of water, and 0.15 kg of copolymer coating wetting and dispersing agent.

[0032] High temperature resistance test The coating was applied to a polyvinyl chloride plate with a coating thickness of 1.2 mm. The polyvinyl chloride plate was placed at 500 °C and the state of the coating was observed.

[0033] Flame retardant performance test The test method and standard refer to UL94 flame retardant grade test.

[0034] The test results are shown in Table 1.

[0035] Table 1 Performance test results of coatings using the copolymer coating wetting dispersant of Examples 1-3 and Comparative Example 2 project High temperature resistance 500 ℃, 12 h Flame retardant grade Example 1 No cracking or falling off V-0 Example 2 No cracking or falling off V-0 Example 3 No cracking or falling off V-0 Comparative Example 1 Cracked but not falling off V-0 Comparative Example 2 Cracking and falling off V-1 As can be seen from Table 1, the coatings using the copolymer coating wetting dispersants of Examples 1-3 will not crack or fall off at 500°C, while the coatings using the copolymer coating wetting dispersants of Comparative Example 2 have poorer high temperature resistance than those of Examples 1-3. The reason is that the zeolite of Comparative Example 2 is not modified and does not generate Si-O-Si bonds with larger bond energy, which leads to poor high temperature resistance of the coatings using the copolymer coating wetting dispersants of Comparative Example 2. Figure 2 The right side of the figure shows the coating to which the polymer coating wetting and dispersing agent of Example 1 is added, and the left side shows the coating to which the polymer coating wetting and dispersing agent of Comparative Example 2 is added. Figure 2 It can be seen that after being subjected to 500°C for 12 h, the coating to which the copolymer coating wetting dispersant of Example 1 was added remained intact, while the coating to which the copolymer coating wetting dispersant of Comparative Example 2 was added partially fell off, indicating that the coating to which the copolymer coating wetting dispersant of the present invention was added has better high temperature resistance.

[0036] Dispersibility test: The copolymer coating wetting dispersant of Examples 1-3 and Comparative Example 1 was added to the coating system, and the viscosity and stability of the coating system were measured. The results are shown in Table 2. The coating system includes 10 kg of propylene emulsion, 10 kg of calcium carbonate, 6 kg of titanium dioxide, 6 kg of calcined kaolin, 8 kg of water, and 0.15 kg of the copolymer coating wetting dispersant.

[0037] Table 2 Dispersibility of the copolymer coating wetting dispersant of Examples 1-3 and Comparative Example 1 project Viscosity (mPa·s) stability Example 1 35 No stratification Example 2 38 No stratification Example 3 36 No stratification Comparative Example 1 43 Slightly delaminated

Claims

1. A copolymer coating wetting and dispersing agent, characterized in that: The invention comprises the following raw materials in parts by weight: 15-25 parts of acrylic acid, 15-25 parts of methyl methacrylate, 10-18 parts of maleic anhydride, 2-3 parts of white carbon black, 2-3 parts of initiator and 15-20 parts of modified zeolite.

2. The copolymer coating wetting and dispersing agent according to claim 1, characterized in that: The preparation method of the modified zeolite comprises the following steps: shaking the zeolite in a silicate solution, adding trimethylsilanol, heating under acidic conditions for reaction, filtering to obtain a filter cake, and freeze-drying the filter cake to obtain the modified zeolite.

3. The copolymer coating wetting dispersant according to claim 2, characterized in that: The mass ratio of the zeolite to the trimethylsilanol is 1:1-1:

3.

4. The copolymer coating wetting and dispersing agent according to claim 2, characterized in that: The silicate is lithium silicate or potassium silicate.

5. The copolymer coating wetting and dispersing agent according to claim 2, characterized in that: The heating temperature is 60-100°C and the reaction time is 3-5 h.

6. The copolymer coating wetting and dispersing agent according to claim 2, characterized in that: The mesh number of the zeolite is 40-70 meshes.

7. The copolymer coating wetting and dispersing agent according to claim 1, characterized in that: The initiator is one or more of ammonium persulfate, potassium persulfate and sodium persulfate.

8. The method for preparing a copolymer coating wetting and dispersing agent according to claim 1, characterized in that: The following steps are involved: Dissolving the coupling agent in ethanol to obtain a mixed solution, mixing the modified zeolite with the mixed solution, and then performing ultrasonic dispersion and drying; The dried modified zeolite, methyl methacrylate, 0.02-0.2 parts of initiator and water are reacted at 70-90 °C for 1-5 hours, and then acrylic acid and maleic anhydride are added and mixed evenly. After cooling, a neutralizing agent is added dropwise to adjust the pH to 6-8; The temperature is raised to 60-90 °C, and the remaining amount of initiator and white carbon black are added and the reaction is continued for 3-5 hours to obtain the product.

9. The method for preparing the copolymer coating wetting and dispersing agent according to claim 8, characterized in that: The coupling agent is one or more of a titanate coupling agent and an aluminate coupling agent.

10. The method for preparing a copolymer coating wetting and dispersing agent according to claim 8, characterized in that: The cooling temperature in step 2) is 30-50°C; the neutralizing agent is sodium hydroxide solution, and the mass fraction of the sodium hydroxide solution is 25-35%.

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